PyAPI: Speed up Mesh.shade_flat() using foreach_set #114591
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Reference: blender/blender#114591
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Delete Branch "Mysteryem/blender:speed_up_mesh_shade_flat"
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Replace the slower iteration in Python with using
foreach_set
and acompatible buffer object filled with
True
.For meshes under 24 faces, the new code is slightly slower due to higher
overhead, but the increase in performance as the number of faces
increases should more than make up for this.
NumPy is only used to create a buffer filled with
True
that iscompatible with
foreach_set
. Thearray
module does not support thebool
/'?'
type, and ctypes arrays are not currently consideredcompatible buffers by
foreach_set
.No changes, other than performance, are expected with this patch.
Time per call for me for meshes with:
ctypes arrays use byte-order/size/alignment prefixes which
foreach_set
doesn't support, which would fall back toforeach_set
's slower iteration.For comparison, using a Python list with
foreach_get
is also many times faster and has less overhead, but is not as fast when the number of faces increases:Time per call using
sharp_faces_data.foreach_set("value", [True] * len(sharp_faces_data))
:Graph of speedup for meshes starting at 6 faces and doubling each time up to 1,572,864 faces:
0af98fa117
tob109c5f668
I've updated the performance comparison following recent performance improvements to
foreach_set
, and I've rebased on main.An alternative that uses
struct.pack
rather thannumpy
could be:This is also slightly faster than using
numpy
, but it doesn't amount to much when the code was already so fast. Notably though, it does have lower overhead, so is faster than the original code for even meshes as small as a default cube.Checkout
From your project repository, check out a new branch and test the changes.