Cycles code refactor: improve vertex motion attribute storage and export.

This now supports multiple steps and subframe sampling of motion.

There is one difference for object and camera transform motion blur. It still
only supports two steps there, but the transforms are now sampled at subframe
times instead of the previous and next frame and then interpolated/extrapolated.
This will give different render results in some cases but it's more accurate.

Part of the code is from the summer of code project by Gavin Howard, but it has
been significantly rewritten and extended.

1 files changed, 15 insertions, 0 deletions

diff --git a/intern/cycles/kernel/geom/geom_object.h b/intern/cycles/kernel/geom/geom_object.h
index 3646615b9f6..b1106c25fd7 100644
--- a/intern/cycles/kernel/geom/geom_object.h
+++ b/intern/cycles/kernel/geom/geom_object.h
@@ -230,6 +230,21 @@ ccl_device_inline float3 object_dupli_uv(KernelGlobals *kg, int object)
 	return make_float3(f.x, f.y, 0.0f);
 }
 
+ccl_device_inline void object_motion_info(KernelGlobals *kg, int object, int *numsteps, int *numverts, int *numkeys)
+{
+	int offset = object*OBJECT_SIZE + OBJECT_DUPLI;
+
+	if(numkeys) {
+		float4 f = kernel_tex_fetch(__objects, offset);
+		*numkeys = __float_as_int(f.w);
+	}
+
+	float4 f = kernel_tex_fetch(__objects, offset + 1);
+	if(numsteps)
+		*numsteps = __float_as_int(f.z);
+	if(numverts)
+		*numverts = __float_as_int(f.w);
+}
 
 ccl_device int shader_pass_id(KernelGlobals *kg, ShaderData *sd)
 {