| Name | Type | Class | What
|
|---|
| Cs | color | Varying | Input surface color
|
| Os | color | Varying | Input surface opacity
|
| P | point | Varying | Input and output surface position
|
| dPdu | point | Varying | Change in surface position wrt u
|
| dPdv | point | Varying | Change in surface position wrt v
|
| N | vector | Varying | Input and Output surface shading normal
|
| Ng | vector | Varying | Surface geometric normal (for culling)
|
| u,v | float | Varying | Surface parameters
|
| du,dv | float | Varying | Change in u,v across element
|
| s,t | float | Varying | Surface texture coordinates (usually = u,v)
|
| L | vector | Varying | Direction from surface to light source
|
| Cl | color | Varying | Incoming light color
|
| Ol | color | Varying | Incoming light opacity
|
| E | point | Uniform | Position of camera
|
| I | vector | Varying | Direction from viewing point to the surface point
|
| Ci | color | Varying | Output surface color
|
| Oi | color | Varying | Output surface opacity
|
| ncomps | float | Uniform | Number of components in each color
|
| time | float | Uniform | Current shutter time
|
| dtime | float | Uniform | Amount of time covered by this shading sample
|
| dPdtime | vector | Varying | How this point is changinf wrt time
|
