Cycles: Added Cryptomatte output.

This allows for extra output passes that encode automatic object and material masks
for the entire scene. It is an implementation of the Cryptomatte standard as
introduced by Psyop. A good future extension would be to add a manifest to the
export and to do plenty of testing to ensure that it is fully compatible with other
renderers and compositing programs that use Cryptomatte.

Internally, it adds the ability for Cycles to have several passes of the same type
that are distinguished by their name.

Differential Revision: https://developer.blender.org/D3538

1 files changed, 20 insertions, 1 deletions

diff --git a/intern/cycles/render/buffers.cpp b/intern/cycles/render/buffers.cpp
index e6021f4b37d..dd20efb3dde 100644
--- a/intern/cycles/render/buffers.cpp
+++ b/intern/cycles/render/buffers.cpp
@@ -233,7 +233,7 @@ bool RenderBuffers::get_denoising_pass_rect(int offset, float exposure, int samp
 	return true;
 }
 
-bool RenderBuffers::get_pass_rect(PassType type, float exposure, int sample, int components, float *pixels)
+bool RenderBuffers::get_pass_rect(PassType type, float exposure, int sample, int components, float *pixels, const string &name)
 {
 	if(buffer.data() == NULL) {
 		return false;
@@ -249,6 +249,14 @@ bool RenderBuffers::get_pass_rect(PassType type, float exposure, int sample, int
 			continue;
 		}
 
+		/* Tell Cryptomatte passes apart by their name. */
+		if(pass.type == PASS_CRYPTOMATTE) {
+			if(pass.name != name) {
+				pass_offset += pass.components;
+				continue;
+			}
+		}
+
 		float *in = buffer.data() + pass_offset;
 		int pass_stride = params.get_passes_size();
 
@@ -385,6 +393,17 @@ bool RenderBuffers::get_pass_rect(PassType type, float exposure, int sample, int
 					pixels[3] = f.w*invw;
 				}
 			}
+			else if(type == PASS_CRYPTOMATTE) {
+				for(int i = 0; i < size; i++, in += pass_stride, pixels += 4) {
+					float4 f = make_float4(in[0], in[1], in[2], in[3]);
+					/* x and z contain integer IDs, don't rescale them.
+					   y and w contain matte weights, they get scaled. */
+					pixels[0] = f.x;
+					pixels[1] = f.y * scale;
+					pixels[2] = f.z;
+					pixels[3] = f.w * scale;
+				}
+			}
 			else {
 				for(int i = 0; i < size; i++, in += pass_stride, pixels += 4) {
 					float4 f = make_float4(in[0], in[1], in[2], in[3]);