lit
Returns a lighting coefficient vector.
| ret lit(n_dot_l, n_dot_h, m) |
|---|
This function returns a lighting coefficient vector (ambient, diffuse, specular, 1) where:
- ambient = 1.
- diffuse = ((n • l) < 0) ? 0 : n • l.
- specular = ((n • l) < 0) || ((n • h) < 0) ? 0 : ((n • h) * m).
Where the vector n is the normal vector, l is the direction to light and h is the half vector.
Parameters
| Item | Description |
|---|---|
|
n_dot_l |
[in] The dot product of the normalized surface normal and the light vector. |
|
n_dot_h |
[in] The dot product of the half-angle vector and the surface normal. |
|
m |
[in] A specular exponent. |
Return Value
The lighting coefficient vector.
Type Description
| Name | Template Type | Component Type | Size |
|---|---|---|---|
| n_dot_l | scalar | float | 1 |
| n_dot_h | scalar | float | 1 |
| m | scalar | float | 1 |
| ret | vector | float | 4 |
Minimum Shader Model
This function is supported in the following shader models.
| Shader Model | Supported |
|---|---|
| Shader Model 2 (DirectX HLSL) and higher shader models | yes |
| Shader Model 1 (DirectX HLSL) | yes (vs_1_1 only) |
See also
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Build date: 3/5/2013
