GLSL: specular transparency support for Blender internal materials

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D781

4 files changed, 21 insertions, 0 deletions

diff --git a/source/blender/gpu/GPU_material.h b/source/blender/gpu/GPU_material.h
index a111401343e..fab9c28cb61 100644
--- a/source/blender/gpu/GPU_material.h
+++ b/source/blender/gpu/GPU_material.h
@@ -159,6 +159,7 @@ typedef struct GPUShadeInput {
 
 	GPUNodeLink *rgb, *specrgb, *vn, *view, *vcol, *ref;
 	GPUNodeLink *alpha, *refl, *spec, *emit, *har, *amb;
+	GPUNodeLink *spectra;
 } GPUShadeInput;
 
 typedef struct GPUShadeResult {
diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index 32d7e04aeea..fa22783ba2a 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -1426,6 +1426,7 @@ void GPU_shadeinput_set(GPUMaterial *mat, Material *ma, GPUShadeInput *shi)
 	GPU_link(mat, "set_value", GPU_uniform(&ma->emit), &shi->emit);
 	GPU_link(mat, "set_value", GPU_uniform(&hard), &shi->har);
 	GPU_link(mat, "set_value", GPU_uniform(&ma->amb), &shi->amb);
+	GPU_link(mat, "set_value", GPU_uniform(&ma->spectra), &shi->spectra);
 	GPU_link(mat, "shade_view", GPU_builtin(GPU_VIEW_POSITION), &shi->view);
 	GPU_link(mat, "vcol_attribute", GPU_attribute(CD_MCOL, ""), &shi->vcol);
 	if (GPU_material_do_color_management(mat))
@@ -1497,6 +1498,12 @@ void GPU_shaderesult_set(GPUShadeInput *shi, GPUShadeResult *shr)
 			}
 		}
 
+		if (ma->mode & MA_TRANSP && (ma->mode & (MA_ZTRANSP|MA_RAYTRANSP))) {
+			if (GPU_link_changed(shi->spectra) || ma->spectra != 0.0f)
+				GPU_link(mat, "alpha_spec_correction", shr->spec, shi->spectra,
+					shi->alpha, &shr->alpha);
+		}
+
 		if (ma->mode & MA_RAMP_COL) ramp_diffuse_result(shi, &shr->combined);
 		if (ma->mode & MA_RAMP_SPEC) ramp_spec_result(shi, &shr->spec);
 
diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index d5bc65eff4f..a737741975e 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -1935,6 +1935,17 @@ void shade_add_spec(float t, vec3 lampcol, vec3 speccol, out vec3 outcol)
 	outcol = t*lampcol*speccol;
 }
 
+void alpha_spec_correction(vec3 spec, float spectra, float alpha, out float outalpha)
+{
+	if (spectra > 0.0) {
+		float t = clamp(max(max(spec.r, spec.g), spec.b) * spectra, 0.0, 1.0);
+		outalpha = (1.0 - t) * alpha + t;
+	}
+	else {
+		outalpha = alpha;
+	}
+}
+
 void shade_add(vec4 col1, vec4 col2, out vec4 outcol)
 {
 	outcol = col1 + col2;
diff --git a/source/blender/nodes/shader/nodes/node_shader_material.c b/source/blender/nodes/shader/nodes/node_shader_material.c
index 79d66495ad7..b7e10c7e9df 100644
--- a/source/blender/nodes/shader/nodes/node_shader_material.c
+++ b/source/blender/nodes/shader/nodes/node_shader_material.c
@@ -267,6 +267,8 @@ static int gpu_shader_material(GPUMaterial *mat, bNode *node, bNodeExecData *UNU
 				shi.amb = gpu_get_input_link(&in[MAT_IN_AMB]);
 			if (hasinput[MAT_IN_EMIT])
 				shi.emit = gpu_get_input_link(&in[MAT_IN_EMIT]);
+			if (hasinput[MAT_IN_SPECTRA])
+				shi.spectra = gpu_get_input_link(&in[MAT_IN_SPECTRA]);
 			if (hasinput[MAT_IN_ALPHA])
 				shi.alpha = gpu_get_input_link(&in[MAT_IN_ALPHA]);
 		}