Cycles: Improved robustness of hair motion blur.motion_curve_fix

In some instances, the number of control vertices of a hair could change mid-frame.
Cycles would then be unable to calculate proper motion blur for those hairs. This adds
interpolated CVs to fill in for the missing data. While this will not necessarily result in
a fully accurate reconstruction of the guide hair, it preserves motion blur instead of disabling it.

Reviewers: #cycles, sergey

Reviewed By: #cycles, sergey

Subscribers: sergey, brecht, #cycles

Tags: #cycles

Differential Revision: https://developer.blender.org/D3695

1 files changed, 69 insertions, 0 deletions

diff --git a/build_files/build_environment/cmake/embree.cmake b/build_files/build_environment/cmake/embree.cmake
new file mode 100644
index 00000000000..8c523e25f0c
--- /dev/null
+++ b/build_files/build_environment/cmake/embree.cmake
@@ -0,0 +1,69 @@
+# ***** BEGIN GPL LICENSE BLOCK *****
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ***** END GPL LICENSE BLOCK *****
+
+# Note the utility apps may use png/tiff/gif system libraries, but the
+# library itself does not depend on them, so should give no problems.
+
+set(EMBREE_EXTRA_ARGS
+	-DEMBREE_ISPC_SUPPORT=OFF
+	-DEMBREE_TUTORIALS=OFF
+	-DEMBREE_STATIC_LIB=ON
+	-DEMBREE_RAY_MASK=ON
+	-DEMBREE_FILTER_FUNCTION=ON
+	-DEMBREE_BACKFACE_CULLING=OFF
+	-DEMBREE_TASKING_SYSTEM=INTERNAL
+	-DEMBREE_MAX_ISA=AVX2
+)
+
+if(WIN32)
+	set(EMBREE_BUILD_DIR ${BUILD_MODE}/)
+else()
+	set(EMBREE_BUILD_DIR)
+endif()
+
+ExternalProject_Add(external_embree
+	URL ${EMBREE_URI}
+	DOWNLOAD_DIR ${DOWNLOAD_DIR}
+	URL_HASH MD5=${EMBREE_HASH}
+	PREFIX ${BUILD_DIR}/embree
+	CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${LIBDIR}/embree ${DEFAULT_CMAKE_FLAGS} ${EMBREE_EXTRA_ARGS}
+	INSTALL_DIR ${LIBDIR}/embree
+)
+if(WIN32)
+
+	if(BUILD_MODE STREQUAL Release)
+		ExternalProject_Add_Step(external_embree after_install
+			COMMAND ${CMAKE_COMMAND} -E copy_directory ${LIBDIR}/embree ${HARVEST_TARGET}/embree
+			DEPENDEES install
+		)
+	else()
+	ExternalProject_Add_Step(external_embree after_install
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/embree3.lib ${HARVEST_TARGET}/embree/lib/embree3_d.lib
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/embree_avx.lib ${HARVEST_TARGET}/embree/lib/embree_avx_d.lib
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/embree_avx2.lib ${HARVEST_TARGET}/embree/lib/embree_avx2_d.lib
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/embree_sse42.lib ${HARVEST_TARGET}/embree/lib/embree_sse42_d.lib
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/lexers.lib ${HARVEST_TARGET}/embree/lib/lexers_d.lib
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/math.lib ${HARVEST_TARGET}/embree/lib/math_d.lib
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/simd.lib ${HARVEST_TARGET}/embree/lib/simd_d.lib
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/sys.lib ${HARVEST_TARGET}/embree/lib/sys_d.lib
+			COMMAND	${CMAKE_COMMAND} -E copy ${LIBDIR}/embree/lib/tasking.lib ${HARVEST_TARGET}/embree/lib/tasking_d.lib
+			DEPENDEES install
+		)
+	endif()
+
+endif()