Cycles: Fix T49901: OpenCL build error after recent light texture coordinate commit

Basically, the problem here was that the transform that's used to bring texture coordinates
to world space is either fetched while setting up the shader (with Object Motion is enabled) or
fetched when needed (otherwise). That helps to save ShaderData memory on OpenCL when Object Motion isn't needed.

Now, if OM is enabled, the Lamp transform can just be stored inside the ShaderData as well. The original commit just assumed it is.
However, when it's not (on OpenCL by default, for example), there is no easy way to fetch it when needed, since the ShaderData doesn't
store the Lamp index.

So, for now the lamps just don't support local texture coordinates anymore when Object Motion is disabled.
To fix and support this properly, one of the following could be done:
- Just always pre-fetch the transform. Downside: Memory Usage increases when not using OM on OpenCL
- Add a variable to ShaderData that stores the Lamp ID to allow fetching it when needed
- Store the Lamp ID inside prim or object. Problem: Cycles currently checks these for whether an object was hit - these checks would need to be changed.
- Enable OM whenever a Texture Coordinate's Normal output is used. Downside: Might not actually be needed.

2 files changed, 4 insertions, 8 deletions

diff --git a/intern/cycles/kernel/svm/svm_image.h b/intern/cycles/kernel/svm/svm_image.h
index 9606064492e..2afdf61b476 100644
--- a/intern/cycles/kernel/svm/svm_image.h
+++ b/intern/cycles/kernel/svm/svm_image.h
@@ -241,8 +241,7 @@ ccl_device void svm_node_tex_image_box(KernelGlobals *kg, ShaderData *sd, float
 	float3 N = ccl_fetch(sd, N);
 
 	N = ccl_fetch(sd, N);
-	if(ccl_fetch(sd, object) != OBJECT_NONE)
-		object_inverse_normal_transform(kg, sd, &N);
+	object_inverse_normal_transform(kg, sd, &N);
 
 	/* project from direction vector to barycentric coordinates in triangles */
 	N.x = fabsf(N.x);
diff --git a/intern/cycles/kernel/svm/svm_tex_coord.h b/intern/cycles/kernel/svm/svm_tex_coord.h
index 6c3394adbce..c0b01262212 100644
--- a/intern/cycles/kernel/svm/svm_tex_coord.h
+++ b/intern/cycles/kernel/svm/svm_tex_coord.h
@@ -49,8 +49,7 @@ ccl_device void svm_node_tex_coord(KernelGlobals *kg,
 		}
 		case NODE_TEXCO_NORMAL: {
 			data = ccl_fetch(sd, N);
-			if((ccl_fetch(sd, object) != OBJECT_NONE) || (ccl_fetch(sd, type) == PRIMITIVE_LAMP))
-				object_inverse_normal_transform(kg, sd, &data);
+			object_inverse_normal_transform(kg, sd, &data);
 			break;
 		}
 		case NODE_TEXCO_CAMERA: {
@@ -131,8 +130,7 @@ ccl_device void svm_node_tex_coord_bump_dx(KernelGlobals *kg,
 		}
 		case NODE_TEXCO_NORMAL: {
 			data = ccl_fetch(sd, N);
-			if((ccl_fetch(sd, object) != OBJECT_NONE) || (ccl_fetch(sd, type) == PRIMITIVE_LAMP))
-				object_inverse_normal_transform(kg, sd, &data);
+			object_inverse_normal_transform(kg, sd, &data);
 			break;
 		}
 		case NODE_TEXCO_CAMERA: {
@@ -216,8 +214,7 @@ ccl_device void svm_node_tex_coord_bump_dy(KernelGlobals *kg,
 		}
 		case NODE_TEXCO_NORMAL: {
 			data = ccl_fetch(sd, N);
-			if((ccl_fetch(sd, object) != OBJECT_NONE) || (ccl_fetch(sd, type) == PRIMITIVE_LAMP))
-				object_inverse_normal_transform(kg, sd, &data);
+			object_inverse_normal_transform(kg, sd, &data);
 			break;
 		}
 		case NODE_TEXCO_CAMERA: {