Enable backface culling for curves in Embree

mitsuba-renderer · Aug 25, 2023 · 188b254 · 188b254
1 parent f465729
commit 188b254
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Showing 4 changed files with 9 additions and 6 deletions.
diff --git a/ext/CMakeLists.txt b/ext/CMakeLists.txt
@@ -87,6 +87,7 @@ if (MI_ENABLE_EMBREE)
   set(EMBREE_GEOMETRY_POINT            OFF CACHE BOOL " " FORCE)
   set(EMBREE_GEOMETRY_SUBDIVISION      OFF CACHE BOOL " " FORCE)
   set(EMBREE_GEOMETRY_CURVE            ON  CACHE BOOL " " FORCE)
+  set(EMBREE_BACKFACE_CULLING_CURVES   ON  CACHE BOOL " " FORCE)
   set(EMBREE_GEOMETRY_INSTANCE         ON  CACHE BOOL " " FORCE)
   set(EMBREE_GEOMETRY_USER             ON  CACHE BOOL " " FORCE)
   set(EMBREE_IGNORE_INVALID_RAYS       ON  CACHE BOOL " " FORCE)

diff --git a/ext/embree b/ext/embree
diff --git a/src/shapes/bsplinecurve.cpp b/src/shapes/bsplinecurve.cpp
@@ -114,11 +114,10 @@ points and increasing radii::
             'filename': 'curves.txt'
         },
 
-.. note:: In CUDA variants, the backfaces of the curves are culled. It is
-          therefore impossible to intersect the curve with a ray which's origin
-          is inside of the curve. In addition, prior to the NVIDIA v531.18
-          drivers for Windows and v530.30.02 drivers for Linux,
-          `important inconsistencies <https://forums.developer.nvidia.com/t/orthographic-camera-with-b-spline-curves/238650>`_
+.. note:: The backfaces of the curves are culled. It is therefore impossible to
+          intersect the curve with a ray that's origin is inside of the curve.
+          In addition, prior to the NVIDIA v531.18 drivers for Windows and
+          v530.30.02 drivers for Linux, `important inconsistencies <https://forums.developer.nvidia.com/t/orthographic-camera-with-b-spline-curves/238650>`_
           in the ray intersection code have been identified.
           We recommend updating to newer drivers.
  */

diff --git a/src/shapes/linearcurve.cpp b/src/shapes/linearcurve.cpp
@@ -108,6 +108,9 @@ points and increasing radii::
             'to_world': mi.ScalarTransform4f.scale([2, 2, 2]).translate([1, 0, 0]),
             'filename': 'curves.txt'
         },
+
+.. note:: The backfaces of the curves are culled. It is therefore impossible to
+          intersect the curve with a ray that's origin is inside of the curve.
  */
 
 template <typename Float, typename Spectrum>