Maya: Texture Maps

smallarrows.GIF

Set Up
Turn off Color Management:
Select Windows->Settings/Preferences->Preferences
Select Color Management
Uncheck Enable Color Management
Select Save


hypershade  Windows->Rendering Editors->Hypershade

Close Material Viewer and Property Editor in the hypershade window
From this:
hypershade_before

To this:
hypershade_after



Color Maps
Color mapping is like gift wrapping.  Color maps apply an image to the surface of an object

hypershade  Windows->Rendering Editors->Hypershade
Under the Create tab, click on Lambert to create a new shader ball.

Select a model.

Use the right mouse key over one of the shader balls to bring up the marking menu, select Assign Material to Selection.

Double click the Lambert shader ball you just assigned.

(You should be in the Lambert tab of the attribute editor on the right.)
Click the Map Button map_button.jpg across from Color, this brings up the Create Render Node window.

Using the 2D Textures filter:
     Select the File icon
To the right of the Image Name click the folder icon
Choose an image, it is best to keep your images in the scenes directory.
     Change Filter Type to Off

Hit 4,5,6 to view the texture shades on the model.

mcm1.jpg



Reflected Color Maps
A reflected color map makes an object appear shiny by reflecting a picture on to its surface. Any picture whether it is painted or rendered can be used as a reflection map. The software takes this image and wraps it around an imaginary sphere, (by default), distortion takes place around the poles of the sphere.

Raytrace will not calculate objects reflecting in each other if the object is using a reflection map. Reflection map can save a lot of rendering time if you are raytracing!

The reflection depends on the position of the object and the FOV (angle of view, or zoom). Round objects catch more reflection than flat objects, especially in computer graphics. Contrast is important to achieve a shiny surface, the darker the surface color the more reflective it will appear. The amount of reflectivity is variable, it is determined by how high the reflectivity is in combination with the specular highlight value. (The specular value also determines how bright the highlight will appear.)

hypershade  Windows->Rendering Editors->Hypershade
In the hypershade window, click on Phong to create a shiny shader ball.

Select a model.

Use the right mouse key over one of the shader balls to bring up the marking menu, select Assign Material to Selection.

Double click the shader ball.
Click the Map Button map_button.jpg across from Reflected Color
Under the Create Render Node window:
     Click Env Chrome (Will work with Maya Software Renderer and Mental Ray Renderer)
Change colors and widths in the chrome procedure.
This procedure is an environment with a grid floor and a sky with rectangle light fixtures.

You will need to render the model to see the reflection.

mcm4.jpg



Bump Maps
Bump mapping is similar to color mapping in approach.  It differs in that it uses black and white data from a color image, these luminance values used to simulate bumps on an object surface.  Bright areas of the picture will appear to raise while dark areas will sink in. The object surface is not actually distorted, it only appears so.

hypershade  Windows->Rendering Editors->Hypershade

Select a model.

Use the right mouse key over one of the shader balls to bring up the marking menu, select Assign Material to Selection.

Double click the shader ball.
Click the Map Button map_button.jpg across from Bump Mapping.
Under the Create Render Node window:
Click File

New tabs called bump2D and file will appear in the Attribute Editor.
Go to file tab in the Attribute Editor.
To the right of the Image Name click the
folder icon.
Choose an image. White areas appear to bump out, black stays the same.

Under the bump2D tab, You can change the apparent height of the bump with the Bump Depth slider, negative or positive numbers work.

Later, you can always find bump2D tab by clicking the connection arrows.
     Double click your shader
     Connect over to the Bump Mapping  connection_arrow2
     Click the lower connection arrow to bring up the bump2d height tab
ConnectionArrow


mcm2.jpg



Transparency Maps
Transparency mapping uses black and white data from a color image or the alpha channel. Luminance values are used to define transparency on the object surface. Dark areas of the picture are transparent while white areas are opaque.

hypershade  Windows->Rendering Editors->Hypershade

Select a model.

Use the right mouse key over one of the shader balls to bring up the marking menu, select Assign Material to Selection.

Double click the shader ball.
Click the Map Button map_button.jpg across from Transparency.
Under the Create Render Node window:
     Click Grid
Turn off Opaque under the Arnold drop-down in the Attribute Editor

mcm3.jpg


File Transparency Maps, Maya, Mental Ray Renderers and Unity:

If you create an image with 1 alpha channel, the alpha channel will automatically create a transparancy map when you apply the image as a color map. (This technique will not work with Arnold. This will work with Unity, remember Unity is single sided, so you will need to duplicate your geometry and invert it.)

color_plus_alpha



File Transparency Maps, Arnold Renderer:

Maya Shader, Arnold Renderer
This is a procedure for Lambert, Blinn and Phong shaders + Arnold
.
Make 2 maps, one for color the other for transparency, it should be negative. (This will not work in Unity unless you make the transparency image inverted positive.)
arnold_transparancy_maya


Arnold Shader
This only works with the Arnold renderer, this will not work with Maya Renderer, Mental Ray or Unity.
I found it difficult to control the specular with this shader.

You will need to use the aiStandard Surface Shader when using transparency with Arnold. Find this Material under the Arnold -> Shader in the Hypershade window.

Select a model.
Turn off Opaque under the Arnold drop-down in the Attribute Editor

Use the right mouse key over one of the shader balls select
Assign Material to Selection.

Under Specular, set IOR (Index of Refraction) to 1
Under Geometry, click the Map Button map_button.jpg across from Opacity.
The white will render out as opaque and black as transparent.

arnold_transparancy_arnoldshader




Delete a Shader
hypershade
  Windows->Rendering Editors->Hypershade
In the hypershade window, select the Lambert shader ball.
Choose Edit->Delete in the hypershade menu. This will not delete any textures associated with it.


Remove Texture from Material
hypershade  Windows->Rendering Editors->Hypershade
Double click a shader ball.
With the right mouse button, click on the attribute next to the item mapped, such as Color.
Choose Break Connection


Delete a Texture

switch to the texture tab
Select the texture you would like to delete
Choose Edit->Delete in the hypershade menu.


Generate a Map with Render.
Create a model, render it to a picture file and use it as a map.

Under the Persp Window's menus:
Select View->Camera Settings->Resolution Gate.


Open Windows->Rendering Editors->Render Settings... render_settings_button
Under Common tab,
Under File Output, Set Image format to Tiff
Under Image Size: Input  256 x 256  Width x Height

Under the Maya Software tab:
Under the arrow Anti-aliasing Quality tab:
Set Quality to: Intermediate Quality

In the Rendering Module:
Use Render->Batch Render



UV Mapping Example

UVmap.jpg

Shape with the 256 x 256 color map
Shape created from skinned cross-sections.



What are 24 bit, 32 bit and 16 million colors?

Red          8 bits per pixel = 256 shades of red
Green      8 bits per pixel = 256 shades of green
Blue         8 bits per pixel = 256 shades of blue

Alpha       8 bits per pixel = 256 shades of transparency for compositing

8 bits per channel x 3 channels RGB = 24 bit total per pixel.
8 bits per channel x 4 channels RGBA = 32 bit total per pixel.

256 x 256 x 256 = 16,777,216 colors available per pixel



Compositing

 utah.jpg                            
background


utahfloweronly.jpg
foreground                   


utahflowermat.jpg
transparency Alpha map  holds out the flower


utahflower.jpg
composite