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-rw-r--r--drivers/gles3/shaders/copy.glsl24
-rw-r--r--drivers/gles3/shaders/scene.glsl77
-rw-r--r--drivers/gles3/shaders/subsurf_scattering.glsl25
3 files changed, 94 insertions, 32 deletions
diff --git a/drivers/gles3/shaders/copy.glsl b/drivers/gles3/shaders/copy.glsl
index d33193ee50..743fe122d1 100644
--- a/drivers/gles3/shaders/copy.glsl
+++ b/drivers/gles3/shaders/copy.glsl
@@ -27,6 +27,8 @@ void main() {
#if defined(USE_CUBEMAP) || defined(USE_PANORAMA)
cube_interp = cube_in;
+#elif defined(USE_ASYM_PANO)
+ uv_interp = vertex_attrib.xy;
#else
uv_interp = uv_in;
#ifdef V_FLIP
@@ -59,6 +61,11 @@ in vec3 cube_interp;
in vec2 uv_interp;
#endif
+#ifdef USE_ASYM_PANO
+uniform highp mat4 pano_transform;
+uniform highp vec4 asym_proj;
+#endif
+
#ifdef USE_CUBEMAP
uniform samplerCube source_cube; //texunit:0
#else
@@ -70,7 +77,7 @@ uniform sampler2D source; //texunit:0
uniform float multiplier;
#endif
-#ifdef USE_PANORAMA
+#if defined(USE_PANORAMA) || defined(USE_ASYM_PANO)
vec4 texturePanorama(vec3 normal,sampler2D pano ) {
@@ -122,6 +129,21 @@ void main() {
vec4 color = texturePanorama( normalize(cube_interp), source );
+#elif defined(USE_ASYM_PANO)
+
+ // When an assymetrical projection matrix is used (applicable for stereoscopic rendering i.e. VR) we need to do this calculation per fragment to get a perspective correct result.
+ // Note that we're ignoring the x-offset for IPD, with Z sufficiently in the distance it becomes neglectible, as a result we could probably just set cube_normal.z to -1.
+ // The Matrix[2][0] (= asym_proj.x) and Matrix[2][1] (= asym_proj.z) values are what provide the right shift in the image.
+
+ vec3 cube_normal;
+ cube_normal.z = -1000000.0;
+ cube_normal.x = (cube_normal.z * (-uv_interp.x - asym_proj.x)) / asym_proj.y;
+ cube_normal.y = (cube_normal.z * (-uv_interp.y - asym_proj.z)) / asym_proj.a;
+ cube_normal = mat3(pano_transform) * cube_normal;
+ cube_normal.z = -cube_normal.z;
+
+ vec4 color = texturePanorama( normalize(cube_normal.xyz), source );
+
#elif defined(USE_CUBEMAP)
vec4 color = texture( source_cube, normalize(cube_interp) );
diff --git a/drivers/gles3/shaders/scene.glsl b/drivers/gles3/shaders/scene.glsl
index 341a5bf2c7..b322a4c957 100644
--- a/drivers/gles3/shaders/scene.glsl
+++ b/drivers/gles3/shaders/scene.glsl
@@ -865,11 +865,57 @@ float contact_shadow_compute(vec3 pos, vec3 dir, float max_distance) {
#endif
-// GGX Specular
-// Source: http://www.filmicworlds.com/images/ggx-opt/optimized-ggx.hlsl
-float G1V(float dotNV, float k)
-{
- return 1.0 / (dotNV * (1.0 - k) + k);
+
+// This returns the G_GGX function divided by 2 cos_theta_m, where in practice cos_theta_m is either N.L or N.V.
+// We're dividing this factor off because the overall term we'll end up looks like
+// (see, for example, the first unnumbered equation in B. Burley, "Physically Based Shading at Disney", SIGGRAPH 2012):
+//
+// F(L.V) D(N.H) G(N.L) G(N.V) / (4 N.L N.V)
+//
+// We're basically regouping this as
+//
+// F(L.V) D(N.H) [G(N.L)/(2 N.L)] [G(N.V) / (2 N.V)]
+//
+// and thus, this function implements the [G(N.m)/(2 N.m)] part with m = L or V.
+//
+// The contents of the D and G (G1) functions (GGX) are taken from
+// E. Heitz, "Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs", J. Comp. Graph. Tech. 3 (2) (2014).
+// Eqns 71-72 and 85-86 (see also Eqns 43 and 80).
+
+float G_GGX_2cos(float cos_theta_m, float alpha) {
+ // Schlick's approximation
+ // C. Schlick, "An Inexpensive BRDF Model for Physically-based Rendering", Computer Graphics Forum. 13 (3): 233 (1994)
+ // Eq. (19), although see Heitz (2014) the about the problems with his derivation.
+ // It nevertheless approximates GGX well with k = alpha/2.
+ float k = 0.5*alpha;
+ return 0.5 / (cos_theta_m * (1.0 - k) + k);
+
+ // float cos2 = cos_theta_m*cos_theta_m;
+ // float sin2 = (1.0-cos2);
+ // return 1.0 /( cos_theta_m + sqrt(cos2 + alpha*alpha*sin2) );
+}
+
+float D_GXX(float cos_theta_m, float alpha) {
+ float alpha2 = alpha*alpha;
+ float d = 1.0 + (alpha2-1.0)*cos_theta_m*cos_theta_m;
+ return alpha2/(M_PI * d * d);
+}
+
+float G_GGX_anisotropic_2cos(float cos_theta_m, float alpha_x, float alpha_y, float cos_phi, float sin_phi) {
+ float cos2 = cos_theta_m * cos_theta_m;
+ float sin2 = (1.0-cos2);
+ float s_x = alpha_x * cos_phi;
+ float s_y = alpha_y * sin_phi;
+ return 1.0 / (cos_theta_m + sqrt(cos2 + (s_x*s_x + s_y*s_y)*sin2 ));
+}
+
+float D_GXX_anisotropic(float cos_theta_m, float alpha_x, float alpha_y, float cos_phi, float sin_phi) {
+ float cos2 = cos_theta_m * cos_theta_m;
+ float sin2 = (1.0-cos2);
+ float r_x = cos_phi/alpha_x;
+ float r_y = sin_phi/alpha_y;
+ float d = cos2 + sin2*(r_x * r_x + r_y * r_y);
+ return 1.0 / (M_PI * alpha_x * alpha_y * d * d );
}
@@ -1019,7 +1065,6 @@ LIGHT_SHADER_CODE
#elif defined(SPECULAR_SCHLICK_GGX)
// shlick+ggx as default
- float alpha = roughness * roughness;
vec3 H = normalize(V + L);
@@ -1035,26 +1080,22 @@ LIGHT_SHADER_CODE
float ay = ry*ry;
float XdotH = dot( T, H );
float YdotH = dot( B, H );
- float denom = XdotH*XdotH / (ax*ax) + YdotH*YdotH / (ay*ay) + cNdotH*cNdotH;
- float D = 1.0 / ( M_PI * ax*ay * denom*denom );
+ float D = D_GXX_anisotropic(cNdotH, ax, ay, XdotH, YdotH);
+ float G = G_GGX_anisotropic_2cos(cNdotL, ax, ay, XdotH, YdotH) * G_GGX_anisotropic_2cos(cNdotV, ax, ay, XdotH, YdotH);
#else
- float alphaSqr = alpha * alpha;
- float denom = cNdotH * cNdotH * (alphaSqr - 1.0) + 1.0;
- float D = alphaSqr / (M_PI * denom * denom);
+ float alpha = roughness * roughness;
+ float D = D_GGX(cNdotH, alpha);
+ float G = G_GGX_2cos(cNdotL, alpha) * G_GGX_2cos(cNdotV, alpha);
#endif
// F
float F0 = 1.0; // FIXME
float cLdotH5 = SchlickFresnel(cLdotH);
float F = mix(cLdotH5, 1.0, F0);
- // V
- float k = alpha / 2.0f;
- float vis = G1V(cNdotL, k) * G1V(cNdotV, k);
-
- float speci = cNdotL * D * F * vis;
+ float specular_brdf_NL = cNdotL * D * F * G;
- specular_light += speci * light_color * specular_blob_intensity * attenuation;
+ specular_light += specular_brdf_NL * light_color * specular_blob_intensity * attenuation;
#endif
#if defined(LIGHT_USE_CLEARCOAT)
@@ -1069,7 +1110,7 @@ LIGHT_SHADER_CODE
#endif
float Dr = GTR1(cNdotH, mix(.1, .001, clearcoat_gloss));
float Fr = mix(.04, 1.0, cLdotH5);
- float Gr = G1V(cNdotL, .25) * G1V(cNdotV, .25);
+ float Gr = G_GGX_2cos(cNdotL, .25) * G_GGX_2cos(cNdotV, .25);
specular_light += .25*clearcoat*Gr*Fr*Dr;
diff --git a/drivers/gles3/shaders/subsurf_scattering.glsl b/drivers/gles3/shaders/subsurf_scattering.glsl
index 20c3b7473f..fc66d66198 100644
--- a/drivers/gles3/shaders/subsurf_scattering.glsl
+++ b/drivers/gles3/shaders/subsurf_scattering.glsl
@@ -82,18 +82,18 @@ QUALIFIER vec2 kernel[17] = vec2[](
const int kernel_size=11;
-QUALIFIER vec4 kernel[11] = vec4[](
- vec4(0.560479, 0.0),
- vec4(0.00471691, -2.0),
- vec4(0.0192831, -1.28),
- vec4(0.03639, -0.72),
- vec4(0.0821904, -0.32),
- vec4(0.0771802, -0.08),
- vec4(0.0771802, 0.08),
- vec4(0.0821904, 0.32),
- vec4(0.03639, 0.72),
- vec4(0.0192831, 1.28),
- vec4(0.00471691,2.0)
+QUALIFIER vec2 kernel[11] = vec2[](
+ vec2(0.560479, 0.0),
+ vec2(0.00471691, -2.0),
+ vec2(0.0192831, -1.28),
+ vec2(0.03639, -0.72),
+ vec2(0.0821904, -0.32),
+ vec2(0.0771802, -0.08),
+ vec2(0.0771802, 0.08),
+ vec2(0.0821904, 0.32),
+ vec2(0.03639, 0.72),
+ vec2(0.0192831, 1.28),
+ vec2(0.00471691,2.0)
);
#endif //USE_11_SAMPLES
@@ -190,4 +190,3 @@ void main() {
frag_color = base_color;
}
}
-
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-04 05:19:20 +0000