Texturing

You have now covered the various types of modelling and the UV mapping process; now, you will work through Texturing. Texturing is an integral part of design production as it is essentially what helps bring life to your models.

As you will have found in the Model topic, some of these subtopics are paired with corresponding subtopics outlining the necessary system steps and videos that you will need for your learning tasks and assessment preparation.

The main subtopics you will explore in Texture include: 

• Maya Materials
• Arnold Materials
• Using the IPR Renderer Process
• Procedural Textures
• Painting Texture Maps.

Learning tasks that will support your skills in digital production have been outlined in the following table. 

Reference

When texturing objects, using a library of your reference material is a good idea to help guide your texture-building process. References can give you excellent ideas about how things in the natural world change over time, how structures are formed, how human-made buildings are put together, etc.

In terms of textures, having references for a range of everyday materials like wood, metal, stone, or tree bark can help inform your texture work and give you a far better understanding of how various materials react to light and weather in the real world, change colouration as they age and so much more.

Creating your library of reference material is as easy as going for a walk with your camera. There are so many exciting opportunities to gather reference material in your everyday life.

Check out the following sliders of natural elements you may capture for inspiration.

The beach

One location where you are bound to find natural elements is the beach. Beaches house interesting rock formations, not to mention coral swept onto the shore and the textures of sand.

Click the arrows in the slider below to view some pictures captured at a beach.

Exploring towns and cities

Exploring local or foreign towns with older buildings, houses with weathered bricks offer great inspiration for texture.

Click the slider below to view various weathered bricks.

Plants

Plant life is another natural element you may wish to draw textural inspiration from. Plants offer unique formations, textures and shapes to utilise in your work.

Having a library of images that you can refer to for inspiration will help you create more grounded works and can be a time saver and a creative advantage in your workflow.

Using your unique reference images can help your work stand out.

It also has the advantage of not requiring copywriting permission to use it. If you took the image yourself, you also have the right to use that image; something that most people don’t think about when trawling through a Google image search looking for something to use in their work.

Texture Schemes

When creating the model's textures, materials, and colours it is key to consider how to generate interest and appeal.

The main areas to focus on while working on textures, materials, and colour for any model are outlined below.

1. Contrast

Effective contrast can draw the eye to a particular part of an image, texture or model.

Contrast can also add interest and appeal to your models through contrasting shapes, large and small, straight and curved, smooth and rough, high detail and low detail.

2. Colour

Colour and combinations of colour can also add or remove appeal in an image, texture or model. Think back to your colour theory lesson from the Foundations portion of this course.

You will remember that there are established guidelines for creating appealing colour schemes—for example, contrasting, complementary, monochromatic, analogous colour schemes, etc.

3. Level of Detail

When working on an image, texture or model, it is critical to ask yourself what level of detail you need to achieve for this piece of work. An object on a mantle in the background of a shot need not be highly detailed but only painted so that the audience can recognise what it is. Conversely, something is going to be seen in a close-up. In that case, you must create enough detail to convince the audience of its authenticity and prevent pixelation in the final render.

4. Weathering

The last thing to consider is the backstory of an object. Has the object had a hard life? Does it show evidence of hard wear and tear? You will remember from the Space crate activity in the Foundations course we needed to consider that the crate would have been moved around a lot in its lifetime and would, therefore, show evidence of that in its texture with damaged and scuffed-up edges and corners.

Part of adding weathering and use to an object or texture is considering where an abject would show its usage. There are some great examples of usage in the real world, like statues with a specific highly polished area where many people have touched them for luck or fertility.

Click on each of the arrows to navigate through the following images.

Creating a texture material swatch sheet

A valuable process when you are creating a texture, material and colour scheme for a model is to go through the process of creating a swatch sheet for the object or model.

The swatch sheet is a high-resolution page that includes your model or concept drawing in the centre with a number of visual examples of the type of texture, material and or colour that each part of the model should be referenced and guided by.

In the following example of a spaceman character, the process involved finding high-resolution examples of the desired textures and materials for each part of the spaceman's costume and skin.

It would also be helpful to include notations on your sheet to help support your ideas and thinking for the textures, materials, colour weathering etc. Especially if you yourself are not going to be the texture artist who is tasked with bringing the textures and materials to life.

Watch the following video tutorial to help you with your texture swatch sheet.

The Hypershade Window

The hypershade window is where you create and manipulate all materials and shading networks in Maya. The steps below walk you through using the hypershade window.

To open the hypershade window:

• Go to Windows>Rendering Editors>Hypershade.
• The hypershade window can also be opened using the hypershade button on the main menu status line.

The hypershade window has been displayed below. Click the arrow to navitagte between the slides.

Watch Geoff, in the following video as he provides you with an overview of the features of Hypershade.

In Maya, there are several different materials available for you to use. There are Maya basic materials that will work in most different render engines, and there are materials that are specific to a set render engine. The current specialised render engine that comes with Maya is called “Arnold”.

Maya Default Materials

The main default materials you will use are:

• Lambert
• Blinn
• Phong
• Phong E
• Anisotropic.

All the default materials in Maya have some common material attributes. The image below illustrates the common material properties and descriptions of each attribute.

Colour

The colour attribute allows you to set a flat colour to your material. Clicking on the colour swatch will open a colour wheel where you can change the colour values.

Transparency

The transparency slider allows you to set how transparent a material is, with the slider all the way to the left it will appear opaque and to the right will appear fully transparent.

Ambient Colour

Ambient colour adds brightness to the colour of the material. With the slider to the left (black), the ambient colour will not affect the material’s colour. As ambient colour is lightened, it will mix with a material's colour and brighten the overall colour. Ambient colour is also affected if there are any ambient lights in the scene.

Incandescence

Incandescence is the colour and brightness that a material appears to be emitting. For example, if you have a material to simulate glowing lava, you can use a bright red incandescence. It is important to note that incandescence does not emit light or illuminate any other objects in the scene.

Diffuse

Diffusing allows a material to reflect light in all directions (0 = no light being reflected in all directions). The diffuse value acts like a scaling attribute for the colour of an object; the higher the value, the closer to the actual surface colour the object will appear. The diffuse value, by default, has a range of 0 to 1, but this attribute can be set to a higher value by manually inputting a value in the input field.

The checkbox icon to the right of each attribute is a button that allows you to link nodes to an attribute. You can use the check box to add a “file” node, for example, to select a pre-painted UV map of a model, which would then be mapped onto your model.

Many different nodes, like noise, patterns, etc., can be applied to the other attributes, which allows for large and sometimes complicated node trees to be created.

Material Specific Attributes

What makes each material type different from each other is how each reacts to and applies light secularity (highlights) to the surface of the model.

Lambert

Lambert does not have any attributes for secularity, it is a flat matte basic material.

Blinn

Blinn is a material shader that is particularly effective at simulating metallic surfaces which typically have soft specular highlights for example, brass or aluminium.

Specular Colour

Specular is the attribute that controls the colour of shiny highlights on the model's surface. Black produces no highlights; the default value is 0.5, and the mid-tone is grey.

Eccentricity

Eccentricity controls the size of shiny highlights on the surface.

Specular Roll Off

Specular roll-off allows the surface to reflect its surroundings (the environment, other surfaces) or the Reflected Colour when viewed at oblique angles. The slider range is 0 to 1. The default value is 0.7.

Reflectivity

Reflectivity gives the surface the ability to reflect its surroundings. The range for the slider is 0 to infinity the default value is 0.5. Note: to generate real reflection raytracing must be turned on in the render settings.

Reflected Colour

Reflected colour represents the colour of light reflected from the material. When raytracing Maya tints the reflections using this attribute. If you are not raytracing, you can map an image texture or environment map to this attribute to create fake reflections which is faster and uses less memory than raytracing.

Phong

Phong Is a material shader that represents glassy or glossy surfaces (such as car mouldings, telephones, bathroom fittings) with a hard specular highlight.

Specular Colour

Specular colour controls the colour of shiny highlight on the surface of the model. Black produces no highlights the default value is 0.5 or a mid-tone grey.

Cosine Power:

Cosine Power controls the size of shiny highlights on the surface.

Reflectivity

Reflectivity gives the surface the ability to reflect its surroundings. The range for the slider is 0 to infinity. The default value is 0.5. Note: raytracing must be turned on in the render settings to generate accurate reflection.

Reflected Colour

Reflected colour represents the colour of light reflected from the material. When raytracing, Maya tints the reflections using this attribute. If you are not raytracing, you can map an image texture or environment map to this attribute to create fake reflections, which is faster and uses less memory than raytracing.

Phong E

Phong E is a material shader that is a simpler version of the Phong material. The specular highlights on Phong E surfaces are softer than those on Phong surfaces, and Phong E surfaces render faster.

Specular Colour:

Specular colour controls the colour of shiny highlights on the model's surface. Black produces no highlights; the default value is 0.5, and the mid-tone is grey.

Whiteness:

Whiteness controls the specular highlight colour. The default is white, but you can choose any colour. You can also map a texture to this value.

Roughness:

Roughness controls the secularity focus.

Highlight Size

Highlight size controls the amount of specular highlight.

Reflectivity

Reflectivity gives the surface the ability to reflect its surroundings. The range for the slider is 0 to infinity. The default value is 0.5. Note: raytracing must be turned on in the render settings to generate real reflection.

Reflected Colour

Reflected colour represents the colour of light reflected from the material. When raytracing, Maya tints the reflections using this attribute. If you are not raytracing, you can map an image texture or environment map to this attribute to create fake reflections, which is faster and uses less memory than raytracing.

Anisotropic

Anisotropic is a material shader representing surfaces with grooves, such as a CD, feathers, or fabrics like velvet or satin. The appearance of specular highlights on an Anisotropic material depends on the properties of these grooves and their orientation. The Specular shading attributes (shiny highlights) determine the grooves' direction and properties.

Specular Colour:

Specular colour controls the colour of shiny highlights on the model's surface. Black produces no highlights; the default value is 0.5, and the mid-tone is grey.

Angle

The angle determines the orientation of the grooves. The range is 0.0 (default) to 360.0. Use to determine the X and Y direction for non-uniform specular highlight.

Spread X/Spread Y:

Spread X/Spread Y determines how much the grooves spread out in the X and Y directions. The X direction is the U direction rotated counterclockwise by the specified Angle degrees. The Y direction is perpendicular to the X direction in UV space.

For Spread X, the range is 0.1 to 100.0 and the default is 13. For Spread Y, the range is 0.1 to 100.0 and the default is 3.0

Roughness:

Roughness determines the overall roughness of the surface. The range is 0.01 to 1.0. The default is 0.7. Smaller values correspond to smoother surfaces and the specular highlights are more concentrated. Larger values correspond to rougher surfaces and the specular highlights are more spread out - similar to being diffused.

Fresnel Index:

Fresnel Index simulates the Fresnel index of a real-world material for example the Fresnel Index for water is 1.33. Values range from 1.0 to 20.0.

Reflectivity

Reflectivity gives the surface the ability to reflect its surroundings. The range for the slider is 0 to infinity the default value is 0.5. Note: to generate real reflection raytracing must be turned on in the render settings.

Reflected Colour

Reflected colour represents the colour of light reflected from the material. When raytracing, Maya tints the reflections using this attribute. If you are not raytracing, you can map an image texture or environment map to this attribute to create fake reflections, which is faster and uses less memory than raytracing.

Anisotropic Reflectivity

Maya automatically calculates reflectivity as a fraction of roughness if anisotropic reflectivity is on. Reflectivity is on by default.

If off, Maya uses the specified Reflectivity value for the environment map (mapped on the Reflected Colour attribute), similar to how the Phong and Blinn materials work. For more information on the default Maya materials go to the Autodesk Maya documentation.

The Maya Arnold render engine has several materials, textures, lights and cameras specifically designed and written to work with the Maya Arnold render engine. Because of this, you will often find that an Arnold material will not render correctly or even display if you use a render engine other than Arnold.

If you cannot see the Arnold renderer or any of its materials, etc., you may need to enable the Arnold plugin in your version of Maya.

Arnold plugins

The following steps will guide you through adding the Arnold plugin.

Step 1

• Go to Windows>Settings and Preferences>Plugin Manager.

Step 2

Scroll down to the Arnold section and ensure that the “mtoa.mll” plugin is loaded and that the auto load option is enabled.

Step 3

You should now be able to see and access the Arnold renderer and features inside of Maya.

All Arnold materials, textures, lights and camera begin for the prefix ai.

Arnold Textures

Let’s take a look at the various textures you can use when using Arnold.

aiStandardsurface

The standard surface material is the main go-to Arnold shader, which incorporates attributes for most of the main areas for material creation. The standard surface material also includes several default presets (car paint, chrome, clay, plastic, rubber, among many more) that give the artist an excellent starting point to create their unique materials inside of Maya.

There are too many attributes to list in this course, so we will only list the base options and urge you to go and have a look at the standard surface material in more detail for yourself.

Base Options

The following table provide you with examples and descriptions of the base options available.

Option	Description
Weight	The base colour weight. 0 will bring the amount of colour in the material to nothing and the surface will appear black 1 will allow full colour.
Colour	Sets the base colour of the material.
Diffuse Roughness	Controls how rough the diffuse colour appears. A value of 0.0 is comparable to the Lambert material. Higher values will result in a rougher surface look more suitable for materials like concrete, plaster or sand.
Metalness	Allows the material to behave like metal. With the metalness attribute set to 0 the material will render like wood, plastic or other non-metallic surfaces. Set the metelness value to 1 to enable metal like behaviours like fully specular reflection and complex fresnel.
Specular Weight	Influences the brightness of the specular highlight.
Specular Colour	Use this colour to 'tint' the specular highlight. You should only use coloured specular for certain metals, whereas non-metallic surfaces usually have a monochromatic specular colour. Non-metallic surfaces normally do not have a coloured specular.
Specular Roughness	Controls the glossiness of the specular reflections. The lower the value, the sharper the reflection. A value of 0 will give you a perfectly sharp mirror reflection, while 1.0 will create reflections that are close to a diffuse reflection.
IOR (Index of Refraction)	Defines the material's Fresnel reflectivity and is by default the angular function used. Effectively the IOR will define the balance between reflections on surfaces facing the viewer and on surface edges. You can see the reflection intensity remains unchanged, but the reflection intensity on the front side changes a lot.
Anisotropy	Reflects and transmits light with a directional bias and causes materials to appear rougher or glossier in certain directions. The default value for anisotropy is 0, which means 'isotropic.' As you move the control towards 1.0, the surface is made more anisotropic in the U axis.
Rotation	Changes the orientation of the anisotropic reflectance in UV space. At 0.0, there is no rotation, while at 1.0 the effect is rotated by 180 degrees. For a surface with brushed metal, this controls the angle at which the material was brushed. For metallic surfaces, the anisotropic highlight should stretch out in a direction perpendicular to the brushing direction.

For more information on the Arnold Standard Surface material go to the Autodesk Arnold documentation at:

https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_user_guide_ac_surface_shaders_ac_standard_surface_html

While there are alot more Arnold materials, we will not be delving into them all in this course.

We will look at using the aiAmbientOcclusion and the aiWireframe materials in the “Presentation” section of this module, where we will look at how to use these Arnold materials to showcase your 3D models for your showreel.

Simulating real world surfaces

You can simulate real world surfaces using default Maya Materials.

Now that we know what each of the default materials and attributes are for, we need to start putting those materials and attributes to use to simulate real world surfaces.

Click the arrows to navigate through each of the examples of materials.

Each different surface reacts differently to the way light interacts with its surface. Learning to observe these qualities of a material surface will enable you to simulate accurate world materials more accurately and, in turn, create more realistic-looking renders.

Procedural Textures

The word procedural in procedural texturing means that the texture uses mathematically generated patterns and textures. Procedurally generated textures are usually faster to compute than painted textures because they are generally far smaller.

Creating textures entirely within Maya using only the default materials, their attributes and the available 2D and 3D textures Maya offers is called procedural texturing. You can create some exceptionally realistic procedural textures using only the nodes within Maya. In this next section, we will look at the process of making some procedural textures and introduce you to some 2D and 3D texture nodes in Maya.

Let's begin to create procedural material by looking at references and deciding on some critical things about the material based on the reference image.

Note: It is important to understand that the material you create is a possible version of the material based on the reference that you have. The same material will look different based on many different variables for example, the lighting at the time the image was taken and the age of the object. Newly machined surfaces are often very different from materials which have been exposed to the weather.

Procedural Concrete

Looking at the above reference image for concrete, we can see that there is very little secularity or highlights due to the rough and unpolished surface of the material.

There is only a small variation in the overall colour of the concrete, ranging from light to mid-tone greys.

By far, the most prevalent feature of the material in the above reference image is the surface detail from the bumps and marks in the surface, ranging from small-scale roughness to some larger-scale bubbles and pitting in the surface.

Using this observational knowledge, you will try to simulate a concrete texture using procedural textures and techniques.

First, you must decide which Maya material would be the best starting point for your concrete material. The answer to this question relies on whether you need specular highlights or any unique properties in the material. This concrete has no specular details, so you won't need those attributes in the material. We can, therefore, choose a Lambert material that does not have any specular properties.

Create a Lambert material and give it a meaningful name like "Concrete_SHDR" Apply the material to your geometry by middle mouse clicking and dragging the material from the Hypershade window to the geometry in the perspective or other camera views.

The steps below guide you through the IPR Renderer. You can return to this subtopic at any time to review the steps via the navigation bar and selecting Using the IPR Renderer subtopic.

Opening the IPR renderer

To open the IPR renderer:

• first open the render settings window.
• you can open the render settings window by clicking on the render button with a cog in the corner.

Choose the software renderer

• Choose the Maya software renderer (IPR Rendering only works with the Maya Software Render Engine).

Select the frame size

Then make sure that you have your preferred frame size selected, you can input this manually or choose from the presets (we are using 1080p or 1920 wide by 1080 pixels high).

Close and accept

• Click on the close button to accept these settings.

Open and use the IPR renderer

• To open and use the IPR renderer, click on the render button with IPR on.

The Render window will open and render the current camera and view of your scene. With the render completed, to start interactive rendering you will first need to select a portion of the render window to set an interactive region. Now with a region selected any changes that you make to your textures will update in real time in the IPR render window.

Watch the following video for an overview and setup of a Render.

Colour

The base colour is the first area to work on inside the concrete material. If you only need a flat colour for your material, set the colour using the colour swatch and colour wheel. However, you want some variation in our base colour, so connect one of the procedural textures already inside Maya to the colour attribute of the Lambert material.

To add a texture to the colour attribute in the attribute editor follow the steps below.

• Click on the checker box to the right of the colour attribute.
  • this opens the create render node window
  • can choose which texture node to add to the colour attribute.

You can apply several nodes, from grid patterns to varying types of noise. Some of the textures are 2D, and some are 3D. You can refine the available textures by selecting one of the categories on the menu on the left. Selecting 2D Textures, for example, will only show you 2D Textures.

Next to each texture is a small thumbnail image of the texture and roughly what it looks like. Each texture type will have its own attributes that you can adjust and change to create the details and look you need in your material.

The best way to select a texture for a particular material is to find one that is nearly what you want and then use its attributes to dial in the texture you are after. For our concrete, we want a two-tone texture that has some variation in the pattern of the colours.

For this example, the Solid Fractal 3D texture is used, but you may wish to experiment with a few of the other textures to create your concrete material.

You can adjust the attribute sliders and values for the Solid Fractal texture to change the way that the pattern is being generated.

To solo a node in the Hypershade window:

• click on the small s button in the top right of its node.
  • This will only show you the output of the node you are currently working on in the material viewer window.
• Click it again to turn soloing off.

Common Procedural Attributes

The following image illustrates the Common Procedural Attributes. Below this image, you will find descriptions of each attribute. Click on each of the headings to read the descriptions.

Click on each of the following headings to learn more about each common procedural attribute.

In the Colour balance area of the fractal attributes, you can adjust the colour of the material by using the Default colour, Colour Gain, and Colour Offset swatches which are a method to Tint your overall colour, Darken and Lighten, respectively.

You can also select the place 3Dtexture node in the Hypershade window if you adjust the position size and scale of the 3D placement of the texture to adjust how the texture looks on the object. If you need the texture to fit your model in the 3D space, you can click on the Fit to Group BBox button, which will fit the 3D placement node around the model exactly.

Notice in this texture that the scale of the place 3D texture node has been made larger to increase the size of the texture on the model.

Surface Detail

The next area to work on is the surface bump detail of the material.

Because there is a fair number of different types of bump detail in the concrete, you must think of each of the different types of bumpiness separately from each other. Create the fine bump detail first and the larger details second, then stack them up to create the final shading network.

Bump1

The first bump detail will be the fine roughness of the surface. The steps below guide you through the process of adding the bump.

• add the first of your bump textures to the bump/normal attribute of the lambert material.
  • Using the checker box button to the right of the attribute.
• use a fractal texture which is a 2D texture.

Using the Fractal attributes adjust the texture to be a fine surface bump detail.

• lower the bump depth of the bump 2D node so that the bump is not too extreme. Bump always looks better using a low bump depth and creating a more subtle overall effect.

• play with the sliders for the fractal effect to create the texture that you like in your concrete material
• solo the texture by clicking on the S button in the top right of a node
  • click it again to turn the soloing off and return to viewing the full material in the material viewing window.

You can also adjust the amount of detail of a texture by adjusting the repeat UV attributes of a texture in the place 2D node. Notice that this texture has had the repeat UV value increased to 30 to create a far finer surface detail than would be possible using the fractal attributes alone.

Bump 2

The second bump detail will add more variation to the bump detail. The following image sliders illustrate the variation in the Stucco window.

Because the Stucco texture is a 3D texture, we will need to use the 3D bump node to connect it to the shading network.

You can stack as many different textures as you need to create the details you want in your bump map.

Connecting the bumps to the network

You will then need to connect the bumps to the network.

To connect more than one bump map to the lambert material, we will use the connection editor to make the connection for the second bump map and create a daisy chain in the Hypershade window. You can make as many different bump maps as you need to create the detail that you want.

Follow the steps below to guide you through connecting the bumps to the network.

To make manual connections between nodes in the work area:

• use the Connection editor which can be found by going to the menu of the Hypershade and choosing:
  • Window>Connection Editor.

The connection editor window will open which has two columns. By Default, the column on the left is the “From” column the column on the right is the “To” column.

• select a node that you want to connect from (we want to connect from the Stucco bump 3D node)
• click the reload left button at the top of the window
• select the node you want to connect to (we want to connect to the fractal bump 2D node)
• click reload right.

You should now have both columns populated with several different attributes.

At the top of the widow in the Left and Right Display menus make sure that the Show Hidden option is checked. Do this for both menus.

To make the connection between the two nodes:

• first select an attribute in the left column (from)
• then select an attribute in the right column (to)
• connect the “outNormal” to the normalCamera attributes.

Shading Network

Congratulations you have now created your first shading network!

You can see the shading network in the work area of the Hypershade. If you want to work on a different texture in the future, you can graph a network and bring it into the work area by following the steps below:

• right mouse selecting the material in your materials area at the top of the Hypershade window
• right mouse click and hold
  • choose the “graph network” option from the marking menu.

Once you have finished, your final rendered procedural concrete should look like the image below.

Metals

Metals like the next example need specular attributes, which means that you must use one of the Maya materials with a specular highlight, these materials are:

• Blinn
• Phong
• PhongE and
• Anisotropic.

Looking at this reference for gold, you can see that it is not smooth and shiny. As a result, the specular highlight is not all that sharp and can spread a little over the surface. We will need to use the eccentricity value in our material to simulate how far the specular highlight spreads over the surface of a model. The specular colour for metal should be a colour that matches the main colour of the material, which will help to make the material look more metallic.

The specular roll-off attribute controls the brightness or intensity of the specular highlight. You can set this value above 1 by attributing a higher value as required.

The colour is set using the main diffuse colour of the material, which can then be made brighter or darker as required by looking at the IPR render and using the ambient colour attribute.

You may also decide that you want to introduce more variation into the main colour of the shader you can do this by adding a texture to the colour attribute as we have done previously. In this case we want to keep the colour in the yellow/green area and have a slight variation in the colours.

There are a few of the 3D textures like Crater Marble, and Stucco that have the option of displaying a few colours so try one of them to add in some variation on the colour of your material shader.

The surface detail of the material can be achieved by daisy chaining several textures together to control the bump of the shading network. This network used two noise texture nodes and a simplex noise texture to create an interesting and varied bump texture.

Your final rendered procedural Gold should look like the example below.

Fresnel Materials

For highly reflective and smooth surfaces like glass and polished surfaces, you must consider how light and reflections react to curved surfaces as they curve towards and away from the camera's point of view.

To simulate this in Maya, we use a sampler info node. This node has a facing ratio attribute that can calculate the angles at which surfaces face the camera.

In the example of a highly reflective car below, you can see the Fresnel Effect in the way that the colour of the paint changes as surfaces curve away from and towards the camera Surfaces that are facing the camera are brighter and more orange than the surfaces that are facing away from the camera. This effect is also apparent in the reflections on the surfaces, with the surfaces facing away from the camera appearing more reflective than those facing the camera.

You first need a material with specular attributes to create a shader that simulates this effect. The Blinn material is an excellent starting point for a shiny and reflective surface.

The Fresnel Effect is achieved using the “Sampler info” node and a “Ramp” node. The sampler info node can be found in the utility area of the Hypershade; the Ramp is a 2D texture.

To connect the nodes, we can connect the ramp into the colour attribute of the Blinn material. To connect the sampler info node to the ramp we will use the connection editor.

Looking at the Ramp attribute we need to note what type of ramp we are currently using; in this case the type is a “V ramp”. This will be important to note for the connection of the sampler info node next.

• Load the sampler info node into the “from” column and the ramp into the “to” column.

To connect the two nodes, follow the steps below:

• select the facing ratio attribute of the sampler info on the lef
• then the vCoord attribute of the ramp.

Adding and changing colour

You can add or change the colour of the ramp.

Adding and changing colours on the ramp will create the Fresnel effect on the model's surface. You can add as many different colours as you like and move the colour locations on the gradient bar by sliding the colours around. This will affect where the colours are located on the model according to its angle to the render camera.

With the colours in this position the yellow/orange value is rendered on surfaces that are facing the camera and the red/orange on the surfaces that are at an angle to the render view.

The sampler info node is especially useful in creating many different types of shaders in Maya, from glass and metal to other fabrics.

To create the effect of metallic flecks in the paint, you can use the sampler info node to add some texture to the material's Ambient colour. In the example below, the granite texture node, which has a cell-like or spotty look, has been used to apply to a new ramp.

The colours of the granite texture are all greyscale tones which will brighten the ambient colouration of the paint on those areas. You can play with the other attribute to get the size and density that you like.

The Granite texture is plugged into one of the colours of the ramp node and then you can play with its position on the ramp and the colour of the second ramp colour to achieve the fall off that you think looks good in your car paint.

The following is an example of the final rendered procedural paint with a slight metallic fleck effect in the material.

Complicated and/or Detailed textures

You may choose to add more complicated and detailed textures to your work.

To achieve more detailed materials Maya has two different layer-based nodes that you can use. The layered shader, and the layered texture. Both work in a similar way in that you can layer and blend materials or textures together before displaying them on a surface.

Layered Shader

You can plug different shading networks into the layers (Lambert, Blinn, Phone, etc). This is handy if you have a model with areas requiring different material attributes, such as a glass bottle with a paper label attached.

Using a Layered shader, you can have a shading network for the glass with a specular highlight and a Fresnel effect with a label material without specular attributes.

The series of images below illustrate the difference in specular values (highlights between the glass of the bottle and the label.

Layered Texture

You can plug textures into its layers (fractal, ramp, marble, etc). Layered textures are suitable for materials that require multiple inputs for an attribute. For example, with more detailed materials, you should have a base colouration with areas of discolouration or oxidation. Because you can only have one input into the colour attribute of a material, you would not be able to do this procedurally. You would have to paint a texture map for the material's colour.

For more complicated and detailed textures like the aged bronze in the image below, you must create a more complex shading network to simulate the detail and nuance in this reference image.

To simulate this material, we must break up its different visual elements. For example, the object's base metal would be the shader's main visual element. Then, you might have another visual component for the areas of oxidation.

It is obvious the condition of the metal is very old; there is weathering evident in the areas of oxidation of the surface, which has created localised areas of green, turquoise, and pale greenish/white.

The surface finish is slightly pitted and is not consistently smooth all over. There are scratches and evidence of use on the surface of the material.

The colouration of the bronze itself is not uniform; some areas are a rich reddish/orange, and others are more subdued brownish/red.

The specular highlights do not look incredibly sharp, are slightly diffused around the edges, and show clear breaks where there are pits and scratches on the material's surface—the specular needs to show up on the areas of the material where oxidation is present.

Base Metal Layer: Bronze

For the base metal layer, we can create a basic bronze shader using a Blinn material.

The colouration of the basic bronze is made using a solid fractal texture with some variations of brown in the colour section.

Oxidation Layer: Turquoise and green oxidation

The oxidation for the material is made using a stucco texture with a light turquoise and a darker green colouration.

To combine the two elements, we can use a layered texture node which is found in the “other textures” area of the Hypershade window.

To add the two textures to the layered texture node follow the steps below.

• Drag and drop each using the middle mouse button in the layers area (the area with a rectangular box) of the layered texture node.
• When a layer is empty it is displayed green, when a layer contains something, it is displayed purple.

The layers are displayed on the material from left to right. The left most layer is on the top and the right most layer is the bottom.

Once you have your layers set up

• connect the layered texture out colour to the colour of the Blinn texture.

If you have the layers in the correct order, you won't see the colour of the oxidation texture. We need to create a mask that cuts through the base metal layer and reveals the oxidation on the layer underneath to display both the oxidation and the base metal layers.

To create the mask layer, we can use any one of the black and white textures in Maya. For this mask, a solid fractal texture is used.

To connect the solid fractal as a mask:

• Connect the out alpha of the fractal texture to the alpha attribute of the base metal layer in the layered texture node.

The mask will create transparent and semi-transparent areas (anywhere the texture is black or shades of grey) of the base metal layer and reveal the oxidation colours beneath.

You can also connect the mask to the specular colour attribute of the material and use this mask to drive where the specular highlights are applied to the model's surface. Anywhere there is oxidation on the surface, there will not be any specular highlights because the mask is black or a shade of grey in those areas (the specular highlight is displayed the brightest in the light areas of the mask).

The surface detail of the material is made using a chain of bump textures; in the example, a solid fractal, a marble, and a mask texture are used to slightly raise the surface of the model in the areas where the oxidation texture is located.

The image below illustrates the final rendered procedural Aged Bronze.

Using what you have learned about the Hypershade window, Maya material types, Material Attributes, and Procedural textures, create procedural shaders for each of the material cubes in the procedural texturing activity.

Watch the following video tutorials to help guide you through the task of creating procedural shaders. 

Now that you have discovered and experimented with procedural textures, it’s time to move on to creating painted texture maps using a UV layout from the UV process you learned about previously.

Colour maps

Painting your own colour maps using a paint program like Adobe Photoshop, allows you far more control over the colour, texture, details and weathering of a 3D object. Adding designs, text and a myriad of other details are now possible where they were not before if you were to only use procedural texturing techniques.

In the example below of a relatively simple model of a Viking Shield, a large amount of the overall interest and narrative of the object is conveyed by the colours and textures. The texture tells a story, which in turn makes for a far more interesting model.

Click the arrows within the slides to navigate through the examples.

Other texture maps

The look of a shader is controlled by many attributes, some of the main ones being bump, specularity, reflectivity, and so on. You can also create painted texture maps to control these attributes.

Most attributes are controlled by values from 0 to 1 or black to white. So, most painted texture maps that control these attributes will be monochromatic or greyscale.

Specular Map

The light areas of a specular map will have the brightest specularity, or highlights, darker areas will have less or none depending on the colour values used in the map.

In the example below for the Viking shield, most of the map is painted in mid grey tones, the lighter areas of the map like the scratches around the edges of the shield, the dragon design, and the blood spatter will appear with the brightest amount of specularity, in the final render as they are the lightest values in the map.

Bump maps

The bump map of an object will also be a greyscale image. The dark values in the image will be the areas where the bump will appear to sink into the surface. Light values in the image will have the opposite effect, making the light areas of the map seem to rise from the surface.

From the example of the Viking shield's main bump map, you will note that several texture details need to be added to the image. The designs from the front of the shield are not present, and the blood splatter is not. Also, the scratches and nicks on the shield's edge are not included.

The missing details mentioned have been separated into their texture maps so that they can be controlled independently. You will also note in these maps that the scratches are now rendered in dark values, which, when applied to the bump attribute, will make them appear to sink into the model's surface.

Click on each of the following headings for other maps you may wish to create for a material shader.

Other maps you may wish to create for a material shader might include:

Adding maps to your material shaders

Adding the painted map is a very simple process, in the list of nodes you can choose to add to an attribute is a node called a “File” node; displayed in the image below.

You can add this node to any attribute in your material. With the node connected to an attribute you can then select a file to display by selecting the browser icon which looks like a folder to the right of the “Image Name” attribute and then navigating to the location your file is saved in.

The filter attribute allows you to blur an image.

The colour balance area of the node allows you to tint, brighten and darken an image being displayed.

Putting the theory into practice

The best way to learn and get better at painting textures for objects is to learn by doing the skills and processes. So, we will put that philosophy into practice and focus on creating the colour, bump and specular maps for a simple 3D model.

Reference

The hammer in the following image, is very similar to the ballpeen model and would make great reference material to work from. You do not have to use this exact reference material and can decide to find your own. Or you may decide that you'd like to try making a texture that shows more weathering on the Model, as if the hammer has been left out in the elements for years accumulating rust and dirt from general neglect.

Texturing approach

Looking at the reference in the image slider above, you can see that two distinct materials make up the hammer's texture. There is a Metal (Steel) and handle material that looks like a leather wrapping.

There is also an excellent vintage-looking label on the shaft that will add another small area of interest that we may have only thought of adding by looking at reference material.

Combining procedural and painted maps

To begin, create a material for the hammer in the hypershade window; the material will need specular attributes, so Blinn, Phong, and PhongE will be our main choices of Maya material.

The Anisotropic material would not be a leading choice because of its unique attributes to control the shape and spread of the specular highlight which doesn't match the steel material we want to simulate.

The metallic texture of the shaft and head of the hammer can be created either using texture maps or by building a procedural shading network.

The leather handle wrappings would be challenging to create using procedural techniques alone, so it would be easier to paint in Photoshop.

The label is impossible to create as a procedural texture and must be part of a custom map.

The Base Metal Shader

We can use a Blinn to create the base metal shader for the shaft and head of the hammer. We will use a textured shader to combine the colour elements of the hammer together.

We can use the layered texture method to create an interesting slightly rusted up looking metal material and stack some different bump materials together to create some varied texture on the surface of the metal.

Remember that we can use the mask that reveals the rust colours on the metal also as a bump node so that the rusted areas appear to stand out from the surface of the model.

The image below highlights the base metal procedural shading network needed for the hammer.

With the procedural part of the texture complete we can move over to Photoshop to paint the colour map for the leather portions of the handle.

Click the arrows to navigate through the texture maps.

As you add more details to your shading network, it can begin to get a little on the confusing side to keep track of it all. It is a good idea to group the nodes that are doing a certain job, like driving the colour attribute of a material for example. This will help to keep your networks manageable as they get more complex.

Now, let’s get practicing!

Watch the videos before commencing this task to help guide you through it.

Further practice with texturing

Now that you have created a basic set of texture maps for a simple model, you can take what you have learned and develop our skills by tackling a model that has little or no procedural textures. For this last texturing activity, you need to create a set of texture maps for our spacecraft models.

Texture your model that you completed earlier in the course.

Try to create a story for the spacecraft, think about ways to add interest and history to the 3D model through the following:

• design
• texture
• detail
• weathering.

Design

Begin your texturing by first thinking about the overall design of the model. What materials are present that will need to be simulated? What colours do you want to see in the final textured model?

Do some research and note what objects like your model look like. In this case, with a spacecraft model, hundreds of well-known and not-so-well-known examples exist online. Get tips and pointers from a handful of these examples and consider the following:

• How many colours have been used?
• Is there a main colour and a detail colour?
• Can you identify any bump details?
• Is there variation evident in the specularity of the model?

Answer these questions for yourself and list style guide pointers that will help you create an exciting texture design.

Texture

You will need to identify areas on your model where there are different textures and materials needed. Consider if there is there any way that you can add interest to the textures through one surface finish contrasting with another either with colour, detail or surface finish (glossy/matte) etc.

While creating your texture maps, think about the level of detail required for each map area. If there are any large unbroken surfaces in the model, you can break them up with painted detail on the map so that they have some interest present that will help slow down the eye when the audience views the model.

Weathering

The last stage of painting a map is to think about the age and weathering that may have happened to a model in its lifetime. Ask yourself the following questions:

• are there surfaces that are exposed to the air more than others?
• are there areas on the model that are located under moving parts that require lubrication?

In these areas, there may be leak or dripping stains where the lubricant has dripped down onto the surfaces below. Corners and edges of an object may be scraped and damaged, the paint or surface of a model may be faded and peeling due to age.

Watch the following videos to help you with this task. Ensure you are watching closely as this task is linked to your Assessment 1.

Congratulations, you have now finished Texture.  As you wrap up this topic, take a few moments to reflect on all that you have achieved, including the various learning tasks to hone your skills.

You have learnt:

• Maya materials
• Arnold materials
• Using the IPR renderer process
• Procedural textures
• Painting texture maps.

Learning task #	Learning Task Name	Duration (Hours)
6	Create a texture material swatch for your space craft model	2
7	Create 9 procedural shaders using default Maya materials	6
8	Create texture maps for the ballpeen hammer model	3

This topic proved to be highly technical and complex, equipping you with the skills, knowledge, and perseverance to apply varying techniques to several digital projects. The skillset and tools you have obtained will be integral to the next topic.