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, 7 insertions, 5 deletions

diff --git a/intern/cycles/blender/blender_camera.cpp b/intern/cycles/blender/blender_camera.cpp
index 4c6b42a9cbc..6bbd4106a96 100644
--- a/intern/cycles/blender/blender_camera.cpp
+++ b/intern/cycles/blender/blender_camera.cpp
@@ -386,7 +386,7 @@ void BlenderSync::sync_camera(BL::RenderSettings b_render, BL::Object b_override
 	blender_camera_sync(cam, &bcam, width, height);
 }
 
-void BlenderSync::sync_camera_motion(BL::Object b_ob, int motion)
+void BlenderSync::sync_camera_motion(BL::Object b_ob, float motion_time)
 {
 	Camera *cam = scene->camera;
 
@@ -394,12 +394,14 @@ void BlenderSync::sync_camera_motion(BL::Object b_ob, int motion)
 	tfm = blender_camera_matrix(tfm, cam->type);
 
 	if(tfm != cam->matrix) {
-		if(motion == -1)
+		if(motion_time == -1.0f) {
 			cam->motion.pre = tfm;
-		else
+			cam->use_motion = true;
+		}
+		else if(motion_time == 1.0f) {
 			cam->motion.post = tfm;
-
-		cam->use_motion = true;
+			cam->use_motion = true;
+		}
 	}
 }