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updateVertexPositions too slow to use for real-time animation loops

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Needs clarification
Activity status
Stale
Tech stack
cpp

Research direction

Start at the updateVertexPositions and userCallback entry points used inside the draw loop, and compare their behavior with libigl's set_vertices and callback_pre_draw path. Profile the 262,144-face animation on the reported macOS setup to identify the source of the frame-time difference. Done means the cause and correct usage are established, with a reproducible performance comparison or a documented limitation.

Written by the indexing model from the issue text.

Description

I'm wondering if I'm using the updateVertexPositions and userCallback correctly. Currently I'm getting around 260 ms/f (4 FPS) when I update the positions of a mesh with 262,144 faces inside the draw loop callback.

If I run a similar animation in the libigl viewer I'm getting 19.9 ms/f (50 FPS). In that scenario I'm using set_vertices and callback_pre_draw.

Here's a video screenshot on my intel macbook pro running catalina:

https://user-images.githubusercontent.com/2241689/147182765-78b15f28-a1ce-4fc6-abf0-f6b44af2728e.mov

( Turning off the polyscope groundplane doesn't seem to change anything. I'm guessing the slowdown is happening in updateVertexPositions)

Dominant language
C++
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Forks
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Avg merge
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Merged PRs (30d)
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