Cycles: Add Mirror ball mapping to camera panorama options

The projection code was already in place, so this just exposes the option.

Differential Revision: https://developer.blender.org/D1079

intern/cycles/blender/addon/properties.py

@@ -66,6 +66,7 @@ enum_panorama_types = (
     ('FISHEYE_EQUIDISTANT', "Fisheye Equidistant", "Ideal for fulldomes, ignore the sensor dimensions"),
     ('FISHEYE_EQUISOLID', "Fisheye Equisolid",
                           "Similar to most fisheye modern lens, takes sensor dimensions into consideration"),
+    ('MIRRORBALL', "Mirror Ball", "Uses the mirror ball mapping"),
     )
 
 enum_curve_primitives = (

intern/cycles/blender/blender_camera.cpp

@@ -148,6 +148,9 @@ static void blender_camera_from_object(BlenderCamera *bcam, BL::RenderEngine b_e
 			case 2:
 				bcam->panorama_type = PANORAMA_FISHEYE_EQUISOLID;
 				break;
+			case 3:
+				bcam->panorama_type = PANORAMA_MIRRORBALL;
+				break;
 			case 0:
 			default:
 				bcam->panorama_type = PANORAMA_EQUIRECTANGULAR;

intern/cycles/kernel/kernel_projection.h

@@ -163,6 +163,10 @@ ccl_device float3 mirrorball_to_direction(float u, float v)
 
 	dir.x = 2.0f*u - 1.0f;
 	dir.z = 2.0f*v - 1.0f;
+
+	if(dir.x*dir.x + dir.z*dir.z > 1.0f)
+		return make_float3(0.0f, 0.0f, 0.0f);
+
 	dir.y = -sqrtf(max(1.0f - dir.x*dir.x - dir.z*dir.z, 0.0f));
 
 	/* reflection */
@@ -191,6 +195,8 @@ ccl_device float3 panorama_to_direction(KernelGlobals *kg, float u, float v)
 	switch(kernel_data.cam.panorama_type) {
 		case PANORAMA_EQUIRECTANGULAR:
 			return equirectangular_range_to_direction(u, v, kernel_data.cam.equirectangular_range);
+		case PANORAMA_MIRRORBALL:
+			return mirrorball_to_direction(u, v);
 		case PANORAMA_FISHEYE_EQUIDISTANT:
 			return fisheye_to_direction(u, v, kernel_data.cam.fisheye_fov);
 		case PANORAMA_FISHEYE_EQUISOLID:
@@ -205,6 +211,8 @@ ccl_device float2 direction_to_panorama(KernelGlobals *kg, float3 dir)
 	switch(kernel_data.cam.panorama_type) {
 		case PANORAMA_EQUIRECTANGULAR:
 			return direction_to_equirectangular_range(dir, kernel_data.cam.equirectangular_range);
+		case PANORAMA_MIRRORBALL:
+			return direction_to_mirrorball(dir);
 		case PANORAMA_FISHEYE_EQUIDISTANT:
 			return direction_to_fisheye(dir, kernel_data.cam.fisheye_fov);
 		case PANORAMA_FISHEYE_EQUISOLID:

intern/cycles/kernel/kernel_types.h

@@ -426,6 +426,7 @@ enum CameraType {
 
 enum PanoramaType {
 	PANORAMA_EQUIRECTANGULAR,
+	PANORAMA_MIRRORBALL,
 	PANORAMA_FISHEYE_EQUIDISTANT,
 	PANORAMA_FISHEYE_EQUISOLID
 };