Cycles microdisplacement: ngons and attributes for subdivision meshes

This adds support for ngons and attributes on subdivision meshes. Ngons are
needed for proper attribute interpolation as well as correct Catmull-Clark
subdivision. Several changes are made to achieve this:

- new primitive `SubdFace` added to `Mesh`
- 3 more textures are used to store info on patches from subd meshes
- Blender export uses loop interface instead of tessface for subd meshes
- `Attribute` class is updated with a simplified way to pass primitive counts
  around and to support ngons.
- extra points for ngons are generated for O(1) attribute interpolation
- curves are temporally disabled on subd meshes to avoid various bugs with
  implementation
- old unneeded code is removed from `subd/`
- various fixes and improvements

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D2108

1 files changed, 3 insertions, 15 deletions

diff --git a/intern/cycles/subd/subd_patch.h b/intern/cycles/subd/subd_patch.h
index bfa04412c66..360c1abf27b 100644
--- a/intern/cycles/subd/subd_patch.h
+++ b/intern/cycles/subd/subd_patch.h
@@ -26,9 +26,11 @@ class Patch {
 public:
 	virtual ~Patch() {}
 	virtual void eval(float3 *P, float3 *dPdu, float3 *dPdv, float3 *N, float u, float v) = 0;
-	virtual bool is_triangle() { return false; }
 	virtual BoundBox bound() = 0;
 	virtual int ptex_face_id() { return -1; }
+
+	int patch_index;
+	int shader;
 };
 
 /* Linear Quad Patch */
@@ -39,19 +41,6 @@ public:
 	float3 normals[4];
 
 	void eval(float3 *P, float3 *dPdu, float3 *dPdv, float3 *N, float u, float v);
-	bool is_triangle() { return false; }
-	BoundBox bound();
-};
-
-/* Linear Triangle Patch */
-
-class LinearTrianglePatch : public Patch {
-public:
-	float3 hull[3];
-	float3 normals[3];
-
-	void eval(float3 *P, float3 *dPdu, float3 *dPdv, float3 *N, float u, float v);
-	bool is_triangle() { return true; }
 	BoundBox bound();
 };
 
@@ -62,7 +51,6 @@ public:
 	float3 hull[16];
 
 	void eval(float3 *P, float3 *dPdu, float3 *dPdv, float3 *N, float u, float v);
-	bool is_triangle() { return false; }
 	BoundBox bound();
 };