EEVEE: Add ensure_valid_reflection to glossy closures

This is ported from Cycles and fixes issues with bump/normal mapping
giving weird reflections/lighting.

Fixes T81070 Specular light should be limited to normal pointing toward the camera
Fixes T78501 Normal mapping making specular artifact
This commit is contained in:
Clément Foucault 2021-03-03 13:14:24 +01:00
parent 87da26404f
commit 1c22b551d0
Notes: blender-bot 2023-06-02 09:42:00 +02:00
Referenced by issue #89320, Smooth Shading renders semi abrupt triangles
Referenced by issue #88400, normal edit modifier make weird specular in 2.93.0 beta
Referenced by issue #88368, Regression: broken normal shading, sharp edges appear on smooth surfaces.
Referenced by issue #88170, Extreme Normal editing causes flat shading
Referenced by issue #81070, Eevee: Specular Light: The sepecular light contribution should be limited to samples with a normal pointing toward the camera
Referenced by issue #78501, EEVEE: Normal mapping making specular artifact
Referenced by issue #108334, Normal map node worked is not correct
2 changed files with 59 additions and 0 deletions

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@ -135,6 +135,60 @@ void accumulate_light(vec3 light, float fac, inout vec4 accum)
accum += vec4(light, 1.0) * min(fac, (1.0 - accum.a));
}
/* Same thing as Cycles without the comments to make it shorter. */
vec3 ensure_valid_reflection(vec3 Ng, vec3 I, vec3 N)
{
vec3 R = -reflect(I, N);
/* Reflection rays may always be at least as shallow as the incoming ray. */
float threshold = min(0.9 * dot(Ng, I), 0.025);
if (dot(Ng, R) >= threshold) {
return N;
}
float NdotNg = dot(N, Ng);
vec3 X = normalize(N - NdotNg * Ng);
float Ix = dot(I, X), Iz = dot(I, Ng);
float Ix2 = sqr(Ix), Iz2 = sqr(Iz);
float a = Ix2 + Iz2;
float b = sqrt(Ix2 * (a - sqr(threshold)));
float c = Iz * threshold + a;
float fac = 0.5 / a;
float N1_z2 = fac * (b + c), N2_z2 = fac * (-b + c);
bool valid1 = (N1_z2 > 1e-5) && (N1_z2 <= (1.0 + 1e-5));
bool valid2 = (N2_z2 > 1e-5) && (N2_z2 <= (1.0 + 1e-5));
vec2 N_new;
if (valid1 && valid2) {
/* If both are possible, do the expensive reflection-based check. */
vec2 N1 = vec2(sqrt(1.0 - N1_z2), sqrt(N1_z2));
vec2 N2 = vec2(sqrt(1.0 - N2_z2), sqrt(N2_z2));
float R1 = 2.0 * (N1.x * Ix + N1.y * Iz) * N1.y - Iz;
float R2 = 2.0 * (N2.x * Ix + N2.y * Iz) * N2.y - Iz;
valid1 = (R1 >= 1e-5);
valid2 = (R2 >= 1e-5);
if (valid1 && valid2) {
N_new = (R1 < R2) ? N1 : N2;
}
else {
N_new = (R1 > R2) ? N1 : N2;
}
}
else if (valid1 || valid2) {
float Nz2 = valid1 ? N1_z2 : N2_z2;
N_new = vec2(sqrt(1.0 - Nz2), sqrt(Nz2));
}
else {
return Ng;
}
return N_new.x * X + N_new.y * Ng;
}
/* ----------- Cone angle Approximation --------- */
/* Return a fitted cone angle given the input roughness */

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@ -3,6 +3,7 @@
#pragma BLENDER_REQUIRE(lights_lib.glsl)
#pragma BLENDER_REQUIRE(lightprobe_lib.glsl)
#pragma BLENDER_REQUIRE(ambient_occlusion_lib.glsl)
#pragma BLENDER_REQUIRE(bsdf_common_lib.glsl)
struct ClosureInputGlossy {
vec3 N; /** Shading normal. */
@ -39,6 +40,10 @@ ClosureEvalGlossy closure_Glossy_eval_init(inout ClosureInputGlossy cl_in,
cl_in.roughness = clamp(cl_in.roughness, 1e-8, 0.9999);
cl_out.radiance = vec3(0.0);
#ifndef STEP_RESOLVE /* SSR */
cl_in.N = ensure_valid_reflection(cl_common.Ng, cl_common.V, cl_in.N);
#endif
float NV = dot(cl_in.N, cl_common.V);
vec2 lut_uv = lut_coords(NV, cl_in.roughness);