Fix #154166: Cycles: Raycast + Bump artifacts

The raycast node disables self intersection when the ray start is the
surface position.
However, this fails when evaluating bump.

This commit adds an extra offset to the ray start (tmin) when
evaluating bump.

Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/154222

tests/python/eevee_render_tests.py

@@ -42,6 +42,8 @@ BLOCKLIST = [
     "light_path_is_diffuse_ray.blend",
     # Blocked due to stochastic diffuse/transmission layering resulting in non-deterministic surfel lighting.
     "principled_bsdf_transmission.blend",
+    # Blocked due to platform-dependent noise differences (likely floating-point/fast-math differences).
+    "raycast_bump.blend",
 ]
 
 BLOCKLIST_METAL = [

tests/python/workbench_render_tests.py

@@ -100,7 +100,7 @@ def main():
     parser = create_argparse()
     args = parser.parse_args()
 
-    blocklist = ["raycast_hit.blend", "raycast_normal.blend", "raycast_position.blend"]
+    blocklist = ["raycast_hit.blend", "raycast_normal.blend", "raycast_position.blend", "raycast_bump.blend"]
     if args.gpu_backend == "vulkan":
         blocklist += BLOCKLIST_VULKAN