void split_bsdf(bsdf &lobes[], bsdf source, float &weights[])
void split_bsdf(bsdf &lobes[], bsdf source, float &weights[], int mask)
void split_bsdf(bsdf &lobes[], bsdf source, float &weights[], int mask, int type)
void split_bsdf(bsdf &lobes[], bsdf source, float &weights[], int mask, int type, float u)
void split_bsdf(bsdf &lobes[], bsdf source, float &weights[], int mask, int type, float u, float cdf[])
&lobes
The function overwrites this array with the BSDFs for the component lobes.
source
The BSDF to split.
weights
The function fills this array with the weights for the split lobes (same length as the returned bsdf array). When you sample Illumination using the returned lobes you must scale it by these weights.
mask
A bitmask indicating which types of bounces to evaluate.
See bouncemask for information on component label bitmasks.
type
How to split the lobes. You can #import "pbr.h" to get constant values representing the different split types:
-
PBR_SPLIT_FULL = 0 -
PBR_SPLIT_RANDOM = 1 -
PBR_SPLIT_ALBEDO = 2 -
PBR_SPLIT_COMPONENT = 3 -
PBR_SPLIT_DEFAULT = PBR_SPLIT_ALBEDO
u
Random value to sample the CDF at.
cdf
CDF used to control sampling among components of the BSDF.
Returns
An array of bsdf objects representing the lobes.
Examples
// Split BSDF into component lobes float weights[]; bsdf lobes[]; split_bsdf(lobes, hitF, weights); // Get albedos of lobes float albedos[]; resize(albedos, len(lobes)); for (int i = 0; i < len(lobes); i++) { albedos[i] = luminance(albedo(lobes[i], -hitnI)) * weights[i]; } // Compute CDF float cdf[] = compute_cdf(albedos); // Randomly select a BSDF based on albedo distribution int index = 0; sample_cdf(cdf, s.x, index); // Do something with the selected BSDF // lobes[index] ...
| See also | |
| bsdf | |
| pbr |
|
| sampling |