Eevee: Fix some problem with Glass & Diffuse BSDF with SSR

Diffuse was not outputing the right normal. (this is not a problem with SSR actually)

Glass did not have proper ssr_id and was receiving environment lighting twice.
Also it did not have proper fresnel on lamps.

4 files changed, 19 insertions, 12 deletions

diff --git a/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl b/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
index 4ee2e778c21..16b3283b624 100644
--- a/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
@@ -742,7 +742,7 @@ vec3 eevee_surface_glass(vec3 N, vec3 transmission_col, float roughness, float i
 	vec3 spec_dir = get_specular_reflection_dominant_dir(N, V, roughnessSquared);
 
 	/* Starts at 1 because 0 is world probe */
-	for (int i = 1; i < MAX_PROBE && i < probe_count && spec_accum.a < 0.999 && trans_accum.a < 0.999; ++i) {
+	for (int i = 1; i < MAX_PROBE && i < probe_count && (spec_accum.a < 0.999 || trans_accum.a < 0.999); ++i) {
 		CubeData cd = probes_data[i];
 
 		float fade = probe_attenuation_cube(cd, worldPosition);
@@ -751,10 +751,10 @@ vec3 eevee_surface_glass(vec3 N, vec3 transmission_col, float roughness, float i
 			if (!(ssrToggle && ssr_id == outputSsrId)) {
 				vec3 spec = probe_evaluate_cube(float(i), cd, worldPosition, spec_dir, roughness);
 				accumulate_light(spec, fade, spec_accum);
-
-				spec = probe_evaluate_cube(float(i), cd, refr_pos, refr_dir, roughnessSquared);
-				accumulate_light(spec, fade, trans_accum);
 			}
+
+			spec = probe_evaluate_cube(float(i), cd, refr_pos, refr_dir, roughnessSquared);
+			accumulate_light(spec, fade, trans_accum);
 		}
 	}
 
@@ -763,12 +763,14 @@ vec3 eevee_surface_glass(vec3 N, vec3 transmission_col, float roughness, float i
 		if (!(ssrToggle && ssr_id == outputSsrId)) {
 			vec3 spec = probe_evaluate_world_spec(spec_dir, roughness);
 			accumulate_light(spec, 1.0, spec_accum);
-
-			spec = probe_evaluate_world_spec(refr_dir, roughnessSquared);
-			accumulate_light(spec, 1.0, trans_accum);
 		}
 	}
 
+	if (trans_accum.a < 0.999) {
+		spec = probe_evaluate_world_spec(refr_dir, roughnessSquared);
+		accumulate_light(spec, 1.0, trans_accum);
+	}
+
 	/* Ambient Occlusion */
 	/* TODO : when AO will be cheaper */
 	float final_ao = 1.0;
@@ -780,9 +782,13 @@ vec3 eevee_surface_glass(vec3 N, vec3 transmission_col, float roughness, float i
 
 	float fresnel = F_eta(ior, NV);
 
+	/* Apply fresnel on lamps. */
+	out_light *= vec3(fresnel);
+
 	ssr_spec = vec3(fresnel) * F_ibl(vec3(1.0), brdf_lut) * specular_occlusion(NV, final_ao, roughness);
 	out_light += spec_accum.rgb * ssr_spec;
 
+
 	float btdf = get_btdf_lut(utilTex, NV, roughness, ior);
 
 	out_light += vec3(1.0 - fresnel) * transmission_col * trans_accum.rgb * btdf;
diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index f8ac92f3258..b667df16101 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -2664,7 +2664,7 @@ void node_bsdf_diffuse(vec4 color, float roughness, vec3 N, out Closure result)
 #ifdef EEVEE_ENGINE
 	vec3 L = eevee_surface_diffuse_lit(N, vec3(1.0), 1.0);
 	vec3 vN = normalize(mat3(ViewMatrix) * N);
-	result = Closure(L * color.rgb, 1.0, vec4(0.0), normal_encode(N, viewCameraVec), -1);
+	result = Closure(L * color.rgb, 1.0, vec4(0.0), normal_encode(vN, viewCameraVec), -1);
 #else
 	/* ambient light */
 	vec3 L = vec3(0.2);
@@ -2720,14 +2720,14 @@ void node_bsdf_anisotropic(
 	node_bsdf_diffuse(color, 0.0, N, result);
 }
 
-void node_bsdf_glass(vec4 color, float roughness, float ior, vec3 N, out Closure result)
+void node_bsdf_glass(vec4 color, float roughness, float ior, vec3 N, float ssr_id, out Closure result)
 {
 #ifdef EEVEE_ENGINE
 	vec3 ssr_spec;
 	roughness = sqrt(roughness);
-	vec3 L = eevee_surface_glass(N, (refractionDepth > 0.0) ? color.rgb : vec3(1.0), roughness, ior, int(-2), ssr_spec);
+	vec3 L = eevee_surface_glass(N, (refractionDepth > 0.0) ? color.rgb : vec3(1.0), roughness, ior, int(ssr_id), ssr_spec);
 	vec3 vN = normalize(mat3(ViewMatrix) * N);
-	result = Closure(L * color.rgb, 1.0, vec4(ssr_spec * color.rgb, roughness), normal_encode(vN, viewCameraVec), int(-2));
+	result = Closure(L * color.rgb, 1.0, vec4(ssr_spec * color.rgb, roughness), normal_encode(vN, viewCameraVec), int(ssr_id));
 #else
 	node_bsdf_diffuse(color, 0.0, N, result);
 #endif
diff --git a/source/blender/nodes/shader/node_shader_tree.c b/source/blender/nodes/shader/node_shader_tree.c
index 29cfc6b0f17..b90297cc631 100644
--- a/source/blender/nodes/shader/node_shader_tree.c
+++ b/source/blender/nodes/shader/node_shader_tree.c
@@ -486,6 +486,7 @@ static bool ntree_tag_ssr_bsdf_cb(bNode *fromnode, bNode *UNUSED(tonode), void *
 		case SH_NODE_EEVEE_SPECULAR:
 		case SH_NODE_BSDF_PRINCIPLED:
 		case SH_NODE_BSDF_GLOSSY:
+		case SH_NODE_BSDF_GLASS:
 			fromnode->ssr_id = (*(float *)userdata);
 			(*(float *)userdata) += 1;
 			break;
diff --git a/source/blender/nodes/shader/nodes/node_shader_bsdf_glass.c b/source/blender/nodes/shader/nodes/node_shader_bsdf_glass.c
index 25f76ba9ecb..1537e07ca16 100644
--- a/source/blender/nodes/shader/nodes/node_shader_bsdf_glass.c
+++ b/source/blender/nodes/shader/nodes/node_shader_bsdf_glass.c
@@ -52,7 +52,7 @@ static int node_shader_gpu_bsdf_glass(GPUMaterial *mat, bNode *node, bNodeExecDa
 	if (!in[3].link)
 		GPU_link(mat, "world_normals_get", &in[3].link);
 
-	return GPU_stack_link(mat, node, "node_bsdf_glass", in, out);
+	return GPU_stack_link(mat, node, "node_bsdf_glass", in, out, GPU_uniform(&node->ssr_id));
 }
 
 /* node type definition */