1 files changed, 59 insertions, 0 deletions
diff --git a/source/blender/draw/engines/eevee/shaders/eevee_deferred_transparent_frag.glsl b/source/blender/draw/engines/eevee/shaders/eevee_deferred_transparent_frag.glsl
new file mode 100644
index 00000000000..92bfa845e87
--- /dev/null
+++ b/source/blender/draw/engines/eevee/shaders/eevee_deferred_transparent_frag.glsl
@@ -0,0 +1,59 @@
+
+/**
+ * Apply transmittance to all radiance passes.
+ *
+ * We needs to evaluate the transmittance of homogeneous volumes if any is present.
+ * Hopefully, this has O(1) complexity as we do not need to raymarch the volume.
+ *
+ * Using blend mode multiply.
+ **/
+
+#pragma BLENDER_REQUIRE(eevee_volume_eval_lib.glsl)
+#pragma BLENDER_REQUIRE(eevee_gbuffer_lib.glsl)
+
+uniform usampler2D volume_data_tx;
+uniform sampler2D transparency_data_tx;
+
+in vec4 uvcoordsvar;
+
+layout(location = 0) out vec4 out_combined;
+layout(location = 1) out vec3 out_diffuse;
+layout(location = 2) out vec3 out_specular;
+layout(location = 3) out vec3 out_volume;
+layout(location = 4) out vec3 out_background;
+layout(location = 5) out vec3 out_holdout;
+
+void main(void)
+{
+  ClosureVolume volume_data = gbuffer_load_volume_data(volume_data_tx, uvcoordsvar.xy);
+
+  /* For volumes from solid objects. */
+  // float depth_max = linear_z(texture(depth_max_tx, uv).r);
+  // float depth_min = linear_z(texture(depth_min_tx, uv).r);
+
+  /* Refine bounds to skip empty areas. */
+  // float dist_from_bbox = intersect_bbox_ray(P, V, bbox);
+  // depth_min = max(dist_from_bbox, depth_min);
+
+  vec3 volume_transmittance;
+  if (volume_data.anisotropy == VOLUME_HETEROGENEOUS) {
+    volume_transmittance = volume_data.transmittance;
+  }
+  else {
+    // volume_eval_homogeneous(P, depth_min, depth_max, volume_transmittance);
+    volume_transmittance = vec3(0.0);
+  }
+
+  vec3 surface_transmittance =
+      gbuffer_load_transparency_data(transparency_data_tx, uvcoordsvar.xy).transmittance;
+
+  vec3 final_transmittance = volume_transmittance * surface_transmittance;
+
+  /* Multiply transmittance all radiance buffers. Remember that blend mode is multiply. */
+  out_combined = vec4(final_transmittance, avg(final_transmittance));
+  out_diffuse = final_transmittance;
+  out_specular = final_transmittance;
+  out_volume = final_transmittance;
+  out_background = final_transmittance;
+  out_holdout = final_transmittance;
+}