Case Study - Cracked glass using materials
This case study by Crazy Mole explores the creation of a cracked glass texture using normal and specular maps (materials) for Second Life. The end result of this case study can be purchased for free from the Second Life Marketplace at: https://marketplace.secondlife.com/p/Cracked-glass-case-study-by-Crazy-Mole/5417411
Making the diffuse glass texture
Using your favorite drawing program, create a texture with the dirt and details you like for the glass and add an alpha layer to it with a gray scale of your choice. Do this by applying a gray setting of, for example, 126,126,126 in the RGB color setting. Fine tuning can eventually be done in Second life after the texture is uploaded.
Making a Normal map
In the same program, make a gray-scaled layer that represents the damage done to the glass (or any other effects you like). Shading represents depth; white is the maximum height and black is the maximum depth. Make a normal map from that image. In Photoshop, you can use the NVidia normal map plug-in.
Making the Specular map
In the same way as the normal map, create a grayscale specular map where white represents the glossiest parts and black represents matte (not shiny) parts.
Export the Materials
Save the specular, normal and diffuse maps, as .png files and upload them to Second Life.
Apply the materials
In Second Life, import a mesh or create a primitive. Place the materials textures in their proper slots on the Texture tab of the Build Tools window. Set the alpha channel in the texture slot to alpha blending and use the transparency option to set the transparency to your preferred glass-like level. In the shininess slot, use Glossiness to adjust the glossiness effect when under direct lighting using the Specular map, and use Environment to set the reflectiveness of the entire object to the environment around it. Play with the settings to get different effects; the numbers range from 0 to 255 for both.
|Note: The specular maps can also have a color which will affect the color of the reflection.|