EEVEE: Volumetrics: Add special attenuation volume for lights

This makes volume lights more efficient if they have lower power.

2 files changed, 14 insertions, 3 deletions

diff --git a/source/blender/draw/engines/eevee/shaders/lights_lib.glsl b/source/blender/draw/engines/eevee/shaders/lights_lib.glsl
index d2daa5a1092..0c26c8d1ff1 100644
--- a/source/blender/draw/engines/eevee/shaders/lights_lib.glsl
+++ b/source/blender/draw/engines/eevee/shaders/lights_lib.glsl
@@ -251,7 +251,11 @@ float light_attenuation(LightData ld, vec4 l_vector)
     vis *= step(0.0, -dot(l_vector.xyz, ld.l_forward));
   }
   if (ld.l_type != SUN) {
+#ifdef VOLUME_LIGHTING
+    vis *= distance_attenuation(l_vector.w * l_vector.w, ld.l_influence_volume);
+#else
     vis *= distance_attenuation(l_vector.w * l_vector.w, ld.l_influence);
+#endif
   }
   return vis;
 }
diff --git a/source/blender/draw/engines/eevee/shaders/volumetric_scatter_frag.glsl b/source/blender/draw/engines/eevee/shaders/volumetric_scatter_frag.glsl
index f75108babe6..dc755aeab8b 100644
--- a/source/blender/draw/engines/eevee/shaders/volumetric_scatter_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/volumetric_scatter_frag.glsl
@@ -40,18 +40,25 @@ void main()
 
 #ifdef VOLUME_LIGHTING /* Lights */
   for (int i = 0; i < MAX_LIGHT && i < laNumLight; i++) {
-
     LightData ld = lights_data[i];
 
+    if (ld.l_volume == 0.0) {
+      continue;
+    }
+
     vec4 l_vector;
     l_vector.xyz = light_volume_light_vector(ld, P);
     l_vector.w = length(l_vector.xyz);
 
-    float Vis = light_visibility(ld, P, l_vector);
+    float vis = light_visibility(ld, P, l_vector);
+
+    if (vis < 1e-4) {
+      continue;
+    }
 
     vec3 Li = light_volume(ld, l_vector) * light_volume_shadow(ld, P, l_vector, volumeExtinction);
 
-    outScattering.rgb += Li * Vis * s_scattering *
+    outScattering.rgb += Li * vis * s_scattering *
                          phase_function(-V, l_vector.xyz / l_vector.w, s_anisotropy);
   }
 #endif