Cycles: principled absorption color now has more effect at lower values.

2 files changed, 3 insertions, 2 deletions

diff --git a/intern/cycles/kernel/shaders/node_principled_volume.osl b/intern/cycles/kernel/shaders/node_principled_volume.osl
index 609fb95866d..ea8d6ab12c5 100644
--- a/intern/cycles/kernel/shaders/node_principled_volume.osl
+++ b/intern/cycles/kernel/shaders/node_principled_volume.osl
@@ -51,7 +51,8 @@ shader node_principled_volume(
 
 		/* Add scattering and absorption closures. */
 		color scatter_coeff = scatter_color;
-		color absorption_coeff = max(1.0 - scatter_color, 0.0) * max(1.0 - AbsorptionColor, 0.0);
+		color absorption_color = sqrt(max(AbsorptionColor, 0.0));
+		color absorption_coeff = max(1.0 - scatter_color, 0.0) * max(1.0 - absorption_color, 0.0);
 		Volume = scatter_coeff * density * henyey_greenstein(Anisotropy) +
 		         absorption_coeff * density * absorption();
 	}
diff --git a/intern/cycles/kernel/svm/svm_closure.h b/intern/cycles/kernel/svm/svm_closure.h
index 819b256bde0..a54095ed127 100644
--- a/intern/cycles/kernel/svm/svm_closure.h
+++ b/intern/cycles/kernel/svm/svm_closure.h
@@ -893,7 +893,7 @@ ccl_device void svm_node_principled_volume(KernelGlobals *kg, ShaderData *sd, fl
 		/* Add extinction weight. */
 		float3 zero = make_float3(0.0f, 0.0f, 0.0f);
 		float3 one = make_float3(1.0f, 1.0f, 1.0f);
-		float3 absorption_color = stack_load_float3(stack, absorption_color_offset);
+		float3 absorption_color = max(sqrt(stack_load_float3(stack, absorption_color_offset)), zero);
 		float3 absorption = max(one - color, zero) * max(one - absorption_color, zero);
 		volume_extinction_setup(sd, (color + absorption) * density);
 	}