blender
/
blender
137
416
Fork 599
Code Issues 6.3k Pull Requests 771 Projects 19 Wiki Activity

Cycles: new Microfacet-based Hair BSDF with elliptical cross-section support #105600

Merged
Weizhen Huang merged 114 commits from weizhen/blender:microfacet_hair into main 2023-08-18 12:46:20 +02:00
Conversation 12 Commits 114 Files Changed 25 +18 -20
4 changed files with 18 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files
Showing only changes of commit 22f9898b4d - Show all commits

21
intern/cycles/kernel/film/denoising_passes.h
View File

@ -55,9 +55,9 @@ ccl_device_forceinline void film_write_denoising_features_surface(KernelGlobals
}
/* All closures contribute to the normal feature, but only diffuse-like ones to the albedo. */
if (sc->type != CLOSURE_BSDF_HAIR_MICROFACET_ID) {
normal += sc->N * sc->sample_weight;
}
/* If far-field hair, use fiber tangent as feature instead of normal. */
normal += (sc->type == CLOSURE_BSDF_HAIR_MICROFACET_ID ? safe_normalize(sd->dPdu) : sc->N) *
sc->sample_weight;
Lukas Stockner commented 2023-08-06 23:37:26 +02:00
Outdated
Review
Copy Link

Is this conditional just due to compatibility?
If yes, and the tangent works better, I think we should just change it for the old model as well.

Is this conditional just due to compatibility? If yes, and the tangent works better, I think we should just change it for the old model as well.
Weizhen Huang commented 2023-08-07 02:11:19 +02:00
Outdated
Review
Copy Link

This piece of code is provided by @olivier.fx. I didn't came up with the logic myself, but for a far-field model the "normal" is always the incoming direction, not really a feature of the object itself, so tangent makes more sense here. For the previous near-field model the normal does influence the appearance and it makes sense to use normal as feature. Not sure if tangent works better, I'm not very knowledgeable about denoising.

This piece of code is provided by @olivier.fx. I didn't came up with the logic myself, but for a far-field model the "normal" is always the incoming direction, not really a feature of the object itself, so tangent makes more sense here. For the previous near-field model the normal does influence the appearance and it makes sense to use normal as feature. Not sure if tangent works better, I'm not very knowledgeable about denoising.
sum_weight += sc->sample_weight;
if (sc->type == CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID) {
@ -68,25 +68,16 @@ ccl_device_forceinline void film_write_denoising_features_surface(KernelGlobals
continue;
}
}
else if (sc->type == CLOSURE_BSDF_HAIR_MICROFACET_ID) {
/* If hair, use fiber tangent as feature instead of normal. */
normal += safe_normalize(sd->dPdu);
}
Spectrum closure_albedo = bsdf_albedo(sd, sc);
if (sc->type == CLOSURE_BSDF_HAIR_MICROFACET_ID) {
if (bsdf_get_specular_roughness_squared(sc) > sqr(0.075f) ||
sc->type == CLOSURE_BSDF_HAIR_MICROFACET_ID) {
/* Hair far field models "count" as diffuse. */
diffuse_albedo += closure_albedo;
sum_nonspecular_weight += sc->sample_weight;
}
else {
if (bsdf_get_specular_roughness_squared(sc) > sqr(0.075f)) {
diffuse_albedo += closure_albedo;
sum_nonspecular_weight += sc->sample_weight;
}
else {
specular_albedo += closure_albedo;
}
specular_albedo += closure_albedo;
}
}

3
source/blender/blenkernel/BKE_node.h
View File

@ -1246,8 +1246,7 @@ void BKE_nodetree_remove_layer_n(struct bNodeTree *ntree, struct Scene *scene, i
#define SH_NODE_COMBINE_COLOR 711
#define SH_NODE_SEPARATE_COLOR 712
#define SH_NODE_MIX 713
#define SH_NODE_BSDF_HAIR_MICROFACET 800
#define SH_NODE_BSDF_HAIR_MICROFACET 714
/** \} */

12
source/blender/gpu/shaders/material/gpu_shader_material_hair.glsl
View File

@ -84,13 +84,21 @@ void node_bsdf_hair_microfacet(vec4 color,
out Closure result)
{
/* Placeholder closure.
* Some computation will have to happen here just like the Principled BSDF. */
* TODO: Some computation will have to happen here just like the Principled BSDF. */
#if 0
ClosureHair hair_data;
hair_data.weight = weight;
hair_data.color = color.rgb;
hair_data.offset = offset;
hair_data.roughness = vec2(0.0);
hair_data.T = g_data.curve_B;
#else
ClosureDiffuse hair_data;
hair_data.weight = weight;
hair_data.color = color.rgb;
hair_data.N = g_data.N;
hair_data.sss_radius = vec3(0.0);
hair_data.sss_id = 0u;
#endif
result = closure_eval(hair_data);
}

2
source/blender/nodes/shader/nodes/node_shader_bsdf_hair_microfacet.cc
View File

@ -168,7 +168,7 @@ static int node_shader_gpu_hair_microfacet(GPUMaterial *mat,
} // namespace blender::nodes::node_shader_bsdf_hair_microfacet_cc
/* node type definition */
/* Node type definition. */
void register_node_type_sh_bsdf_hair_microfacet()
{
namespace file_ns = blender::nodes::node_shader_bsdf_hair_microfacet_cc;