OpenSubdiv issues with large and complex meshes

I made a build. By now I didn’t see improvement from a user point of view in the test files. But is a good step.

PD: My fault, I didn’t stash some Diff and the push didn’t happen. My test are not valid.

Yep, I have seen improvement in the new build. Still not so good like 2.79 legacy Subdivision.

In version 2.81 and 2.82 almost nothing has changed.
In 2.83 will the right priority be given to this problem? Does anyone make animations with Blender (using subdivisions)?

I don’t see any substantial improvements in 2.82.7. This is the difference on my PC (Blender 2.82 vs Maya). Incredible slowness of the subdivisions when playing a simple shape animation.

Blender subdivision level 1 (only one level!), frame rate 3 fps
Maya subdivision level 2 (1.276.800 tris), frame rate 160 fps
Blender 2.79 subdivision level 2 (1.276.800 tris), frame rate 59 fps

I didn’t see any update to solve this main problem of blender. Maybe it’s necessary to take a look of this problem @dfelinto


I creating a new post! Perhaps highlighting the slowness in animation the problem will be taken into consideration, I hope!


@dfelinto cmon guys, we’reporting this problem since the beginning of 2.8!
People need to work here, fix the important issue plz…


Agree, i remember when opensubdiv replaced the old code in the 2.8 branch and we were promised the old performance back and improvements like vertex crease in addition to edges. Faster and gpu accelerated open-subdiv … but nothing has changed in subdiv speed since then , it’s so slow compare to even pre-2.8 and it’s been a year or so already.
Here is a change log from 2.8 release :
"Note however there are still some missing features and performance problems in the new implementation. Particularly animation playback and moving of vertices in edit mode will be improved before the final 2.80 release, to bring it back to 2.7x level.

Further optimizations and features to be added later in the 2.8 series:

  • GPU accelerated subdivision (as existed in Blender 2.7x with the Use OpenSubdiv option)
  • Vertex creases support (to mark vertices as sharp or semi-sharp).
  • Better interoperability with other software, by supporting options for UV and boundary interpolation. "

None of this happened.
subdiv is such a huge part of any dcc i don’t know how the devs keep ignoring it


+++, I also think it must be a high priority. It is more important then new features. Need to return 2.79 speed.


We are still in the 2.8 series of updates, so saying “None of this happened” is false.

Everything just takes time. Subdiv performance needs to be tackled but so do so many other aspects of Blender. Work on one aspect doesn’t negate another, and it’s only a matter of time before these important issues are improved.

Understandable but sub-div is not “just another aspect of blender”. It’s a core functionality and it’s almost unusable for more than a year. Well if they didn’t have time or priority for it they could’ve just hold open-subdiv implementation until it’s ready. Old subdiv worked just fine in 2.8 builds before they replaced it with the new one.
When i said “none of this happened” i obviously was referring to the open-subd related issues. It’s not even about GPU acceleration. Pre 2.8 never had GPU acc. in edit mode, and compare edit mode in 2.79 and 2.8 - it’s like night and day difference. Devs even said they would “bring it back to 2.7 speed” BEFORE 2.8 release. Something is definitely wrong, open-subdiv can’t be so slow by itself.

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That’s not true, Subdivision must have been solved before 2.80 like devs told. But like always

  • Yeah, it will be before 2.80
  • For 2.81
  • For 2.82
  • For 2.83
  • Yeah, we think it is a long term feature
  • Subdivision? I don’t remember that it work better before. Yeah, in 2.79 it worked better, but we need to accept some limitations to improvements…

maybe better to make new separate build with new slow implementation , and in master build turn back 2.79 subdiv. And remove 2.79 subdiv version from master only when new implementation will be the same speed.
Because it is strange to replace old feature on more slow new version without big advantages.Of course new subdiv have more potential in the future, but maybe need to put in in master only when it works not worse that it was in 2.79? Just my thoughts, maybe I am wrong. I love what developers do , I like that priority for 2020 is undo speedup and speedup for editing high ploy meshes. But subdiv must be also in priority of 2020.

HooglyBoogly I was thinking the same around a year ago, but now need to make something, that why we all write here , so developers can see what is important for users and what is missing in priority .
I hope @dfelinto will see this topic.Thanks.


@dfelinto @sergey what’s the problem for implementing the features we miss on this?


It is a matter of priorities. There are other more critical animation playback issues that take precedent.

Animators are struggling even when using Simplify at level 0. Having more efficient OpenSubdiv would help with that, but it is something to be tackled afterwards.

But you can keep an eye on that project on:


As for the highpoly modelling (which indeed is a super important use case), this should be tackled as part of the Edit Mode Performance project.

You can read more details here: T68891 (and I probably will need to close one of these two tasks as duplicated of the other - T68891 & T68996) ).


@dfelinto subdivision perfomance problem is not a problem for animators

Is a problem for

  • animators
  • Modelers
  • Undo (yeah, undo is slower when you have a subdivision in the scene)

It’s a bigger problem. You only need to see users complaining about this in any part of the program.


Fast SubDs are a standard that’s hard to give up on. Modeling, expression creation, correction shape, playback of any animation, cloth simulation, etc.
The GPU manages millions of triangles without slowing down.
Consider that the SubD in a 3D software are as important as the tomato on the pizza! Thanks!!

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To be clear, there are multiple performance projects for 2020:

  • Faster high-poly mesh editing
  • Faster animation playback
  • Faster object mode performance

These all have equal priority and will be mostly worked on by different developers in parallel. High-poly mesh editing and animation playback both are affected by subdivision surfaces and performance will be looked at in the context of both.


@brecht keep an eye on that plz. We trust you!!! :wink:

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