Illum Shader

Overview

The Illum Shader is the most commonly used shader. It can be used to create an extremely wide variety of effects. If there is no specific shader for the type of effect you are trying to achieve, use the Illum Shader.

Detail Bump Map and Vertex Color

1. Diffuse maps are the most common kind of texture maps. They define the color and pattern of the object.

2. Specular maps represent the specular intensity and color of material highlights.

3. Bumpmap adds the illusion of depth to the material.

4. Detail mapping allows the adding of more detail to surfaces. It works like a second material layer and it is not affected by the mapping of the model it is used for. To use it as a Detail bump map add a tileable normal map to the detail map channel.

5. Enable Detail bump mapping. Detail bump maps are similar to detail maps, but differ in that they add depth to the material. Detail bump maps are, like normal maps, affected by light.

6. Detail tilling U sets the amount of tilling used on the detail bump maps U coordinates

7. Detail tilling V sets the amount of tilling used on the detail bump maps V coordinates

8. Detail bump scale defines the bump intensity.

9. Activate the use of Vertex Colors. Allows the use of fake ambient occlusion by using vertex colors, or adds a bit more depth and contrast to the 3D model. Vertex colors have to be added to the geometry in the 3D modeling software.

Without and with detail bumpmap and color.

Glow in Diffuse Alpha

10. Enable the use of Glow in Diffuse Alpha. It only works if the Glossiness slider > 0.

11. The glow map is stored in the alpha channel of the Diffuse map, it has to be a greyscale texture. By painting the alpha channel black and white you can decide what part of the geometry should glow.

12. The Decal slot carries the special map for the glow. This map decides the color of the glow.

13. Alpha glow multiplier defines the intensity of the glow.

Without glow (left) and with glow (right).

Gloss Map DifAlpha

14. The Gloss Map DifAlpha is quite similar to a specular map, but the texture is stored in the alpha channel of the diffuse map. Only grayscale textures can be used. It is cheaper than using a Specular map because the specular map uses all RGB values; but, it also means you can not have colored speculars because for that you actually need a Specular map.

15. The Diffuse map has to have a greyscale alpha channel to be able to use the Gloss Map DifAlpha

16. Glossiness defines a sharp or scattered specular reflection. With values > 10 there is a sharp specular reflection.

Diffuse map and diffuse alpha.

Pipe without gloss (left) and with gloss (right).

Environment Map and Anisotropic Specular

17. To be able to see reflections, you have to enable Environment map.

18. To make a material reflective you need an Environment map or cubemap.

19. The Specular level of the geometry has to be > 0 in order to be able to see the reflection.

20. Reflection Amount defines the intensity of the reflection.

22. 21. Fresnel Bias and Fresnel Scale determine how much reflection vs. refraction is visible for any given pixel depending on what angle you look at the surface. The higher the value the more reflection is visible. It only works if Reflection Amount is > 0.

23. You can Disable rain layer for the material by using this check box.

24. Enables the use of Anisotropic specular, which allows the highlight to have dependency on orientation. See Anisotropic Specular Highlights for more information.

25. Anisotropy Shape defines the shape of specular highlight (0.5 is isotropic, 1 is radial, 0 is disk).

PerPixel Spec. Shininess

Very often there are different types of materials on one texture, especially in the case of character textures. In this case there is a metal and cloth texture on one texture sheet.

26. Per Pixel Spec. Shininess allows you to add different glossiness values to the material. Cloth normally has a different glossiness attribute than metal. But if you have both materials on your texture map, it is often very difficult to make both materials look good just by tweaking the specular map. You can use a map in the alpha channel of the specular map to control the glossiness value.

The darker the color, the smaller the glossiness value. A gray color represents a glossiness value of ~10. It is very important that you don’t use RGB 255.255.255 white and RGB 0.0.0 black in this map Because of technical reasons, these values break the material. On the left is the specular map with a simple glossiness intensity map in the alpha channel. The darker color means that this part will have a smaller glossiness value than the part above.

Specular map	Specular alpha

Without Per Pixel Spec. Shininess	With Per Pixel Spec. Shininess

You can see that the cloth glossiness value is lower and the specular reflection is much wider in this area, because the value set for this area is darker than the metal area.

Offset Bump Mapping

27. Enable Offset bump mapping. Offset bump mapping is a combination of bump mapping and normal mapping. It has a better depth effect than normal mapping. For offset bump mapping, a normalmap and a heightmap are required.

28. The heightmap has to be stored in the alpha channel of the normalmap, which loads to the Bumpmap slot.

29. To adjust the displacement effect use the OBM Displacement slider.

Normal map and its alpha

Without Offset bump mapping	With Offset bump mapping

Decal, Character Decal and Merged Decal

30. Activate this function if you use a Decal. Decal planes are normally placed very close to other geometry. By activating decal, you can avoid typical problems like flickering and z-fighting when faces are close to each other. The decal position will be adjusted and the render priority changed. For more information please see Placing Decals.

31. Character Decal was created for testing purposes, and is not actively supported.

32. DetailMap mask in diffuse alpha allow the artists to use the alpha channel in RGBA texture map to mask the decal.

Dirtlayer

Please note that the Dirt Layer is in the process of being replaced by Blend Layer. Look for new documentation soon.

33. Enable the use of Dirtlayer. The dirt shader allows you to blend another texture onto your base material in the same draw call without the need to place an extra decal. If you would like to read more about Dirtlayer, please see Dirt Layer.

34. Use the Custom slot for your Dirt texture map. The texture itself supports an alpha channel, and the amount of blending into the base material is controlled through the vertex alpha in your mesh and a shader attribute.

35. Dirt Tint allows you to tint your texture. Set it to white for no tinting.

36. Dirt Strength allows you to set the overall opacity of your Dirt Texture

37. Dirt Gloss allows you to set the glossiness of your Dirt Texture.

38. Dirt map alpha controls the opacity of the dirt.

39. Dirt Tiling allows you to set the scale of your Dirt Texture

Different use of dirt layer.

Blend Layer

For information about setting up and using the Blend Layer, please see the sub-page attached to this one.

Parallax Occlusion Mapping

For information about setting up and using Parallax Occlusion Mapping, please see the sub-page attached to this one.

Displacement and Tessellation

For information about setting up and using Tessellation and Displacement, please see the sub-page attached to this one.