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, 35 insertions, 2 deletions

diff --git a/intern/cycles/render/mesh.cpp b/intern/cycles/render/mesh.cpp
index c6ddb00e76b..0d09328119c 100644
--- a/intern/cycles/render/mesh.cpp
+++ b/intern/cycles/render/mesh.cpp
@@ -187,6 +187,24 @@ void Mesh::compute_bounds()
 
 		for(size_t i = 0; i < curve_keys_size; i++)
 			bnds.grow(float4_to_float3(curve_keys[i]), curve_keys[i].w);
+		
+		Attribute *attr = attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
+		if (attr) {
+			size_t steps_size = verts.size() * (motion_steps - 1);
+			float3 *vert_steps = attr->data_float3();
+	
+			for (size_t i = 0; i < steps_size; i++)
+				bnds.grow(vert_steps[i]);
+		}
+
+		Attribute *curve_attr = curve_attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
+		if (curve_attr) {
+			size_t steps_size = curve_keys.size() * (motion_steps - 1);
+			float3 *key_steps = curve_attr->data_float3();
+	
+			for (size_t i = 0; i < steps_size; i++)
+				bnds.grow(key_steps[i]);
+		}
 
 		if(!bnds.valid()) {
 			bnds = BoundBox::empty;
@@ -197,6 +215,22 @@ void Mesh::compute_bounds()
 
 			for(size_t i = 0; i < curve_keys_size; i++)
 				bnds.grow_safe(float4_to_float3(curve_keys[i]), curve_keys[i].w);
+			
+			if (attr) {
+				size_t steps_size = verts.size() * (motion_steps - 1);
+				float3 *vert_steps = attr->data_float3();
+		
+				for (size_t i = 0; i < steps_size; i++)
+					bnds.grow_safe(vert_steps[i]);
+			}
+
+			if (curve_attr) {
+				size_t steps_size = curve_keys.size() * (motion_steps - 1);
+				float3 *key_steps = curve_attr->data_float3();
+		
+				for (size_t i = 0; i < steps_size; i++)
+					bnds.grow_safe(key_steps[i]);
+			}
 		}
 	}
 
@@ -992,7 +1026,6 @@ void MeshManager::device_update(Device *device, DeviceScene *dscene, Scene *scen
 	foreach(Shader *shader, scene->shaders)
 		shader->need_update_attributes = false;
 
-	float shuttertime = scene->camera->shuttertime;
 #ifdef __OBJECT_MOTION__
 	Scene::MotionType need_motion = scene->need_motion(device->info.advanced_shading);
 	bool motion_blur = need_motion == Scene::MOTION_BLUR;
@@ -1001,7 +1034,7 @@ void MeshManager::device_update(Device *device, DeviceScene *dscene, Scene *scen
 #endif
 
 	foreach(Object *object, scene->objects)
-		object->compute_bounds(motion_blur, shuttertime);
+		object->compute_bounds(motion_blur);
 
 	if(progress.get_cancel()) return;