Sign in to follow this  

Materials: Normal and Specular Mapping


Without and with.png

Normal and specular maps in Second Life are texture layers that convey additional rendering information to the graphics engine.  This additional information is used in conjunction with standard "diffuse" textures to add a whole new level of detail to otherwise flat surfaces without drastically increasing either land impact or graphical or server lag.

 

Tip: Applying a normal or specular map to an object does cause the object's land impact to be calculated using the standard land impact parameters rather than prim count.  However, the maps themselves do not contribute to the land impact rating.
 

Normal maps

Applying a normal map.png

Normal mapping is a method of simulating the lighting of bumps and dents on an otherwise flat surface, creating the illusion of a physically detailed surface.  In Second Life, this technique can be used to add detail to a geometrically simple object without significantly increasing the object's land impact or sacrificing graphical performance.

The normal map itself is stored as a texture, with the red, green, and blue values representing the X, Y and Z coordinates of the surface normal.

To apply a normal map to an object you own in Second Life:

  1. Right-click the object and click Edit.
  2. Click the Texture tab in the Build Tools window.
  3. Click the Texture (diffuse) dropdown menu and select Bumpiness (normal).
  4. Click the box above the word Texture to open the Pick: Texture window.
  5. Choose a normal map texture from your inventory and click OK.
  6. The normal map is applied to your object.
 

Specular maps 

Applying a specular map.png

Specular mapping is a method used to define the shape of shiny or reflective areas on a surface.  For example, if a textured surface represents a wooden box with metal parts, a specular map can be applied to define only the metallic portions of the texture as shiny.  In Second Life, specular mapped surfaces reflect light cast by either the sun or local lights.

Specular maps are stored as RGBA textures; The reflected color is tinted by the RGB value (a red specular map reflects white light as if it is red), and the alpha channel conrols the intensity of the reflected environment map.

To apply a specular map to an object you own in Second Life:

  1. Right-click the object and select Edit.
  2. Click the Texture tab in the Build Tools window.
  3. Click the Texture (diffuse) dropdown menu and select Shininess (specular).
  4. Click the box above the word Texture to open the Pick: Texture window.
  5. Choose a specular map texture from your inventory and click OK.
  6. The specular map is applied to your object.
  7. Increase Glossiness to increase the reflectiveness of your specular mapped area; increase Environment to increase the intensity of the reflected environment map.  Glossiness and Environment are also modulated by the alpha channel of the specular map.
Tip: If you want to access the GlossinessEnvironment, and Color controls for your entire object without applying a specifically shaped specular map, you may click the Blank button in the texture picker for a completely white texture.
 


Advanced techniques and technical details 

You can find case studies, advanced techniques, and technical details on Second Life's normal and specular mapping features at the Good Building Practices portal on the Second Life wiki.  

  • Like 1
Sign in to follow this  


User Feedback


There are no comments to display.