Very slow playback with Subdivision modifier 2.81, 2.82, 2.83

Archive User Feedback
1

Playback of an animated mesh with shape or bones is very slow with the subdivision modifier (2.8, 2.81, 2.82.7, 2.83) It is a very serious problem for characters and creatures animation.
I attach 3 videos.
The problem had been resolved in older versions of Blender (2.7) as you can see in this video where Sharybin shows a dragon flapping its wings (2014):

Test: 200 x 200 sphere

Blender 2.82.7
Subdivision level 1
Frame rate: 3 fps

Blender 2.79b
Subdivision level 2
Frame rate: 59 fps

Maya 2018
Subdivision level 2
Frame rate: 160 fps



3 Likes
2

Just to clarify one thing, the Subdivision you’re showing in 2.79 runs on the GPU when “use OpenSubdiv” is enabled while 2.8x is always on the CPU, and AFAIK Blender playback is capped at 60FPS, don’t know why though.

3

If the subdivisions do not use the GPU the 2.8 is unusable for character animation. In 2.83 will the problem be solved?

4

GPU Accelerated OpenSubdiv is on the roadmap but there is not estimate when it will be added and there is another whole problem with the Multires.

1 Like
5

Could you send me a link where the developers talk about this problem?
To switch from other software to Blender, basic functions such as opensubdivision (GPU) should be implemented with the utmost urgency, it is from 2018 that we talk about it …

6

I’ve been talking about this problem for a year and a half. No one’s been able to tell me yet

  • Because we don’t have GPUs now when we had it at 2.79
  • Why is it so difficult to implement the GPU again?
  • Because I haven’t seen a single attempt to solve the problem in a year
  • Because it has not been left while the subdivision of 2.79 was working perfectly until this problem was solved. Even if it was deprecated.

This problem is paramount in blender, as well as the undo and edit the meshes in high poly. These are the three fundamental problems of blender.

7

They were talking about it when the old code was changed to open-subdiv but nothing has changed since then (https://wiki.blender.org/wiki/Reference/Release_Notes/2.80/Modeling#Subdivision_Surfaces_and_Multires). I like everything about 2.8 over pre-2.8, but subdiv part is the worst problem of 2.8, you literally can’t even model with subdiv on, you have to turn it off/on and you never had to do this before 2.8 for performance reasons. Please devs, if you are reading this, we REALLY need at least pre-2.8 speed back. Please

3 Likes
8

Agree ,need to turn back 2.79 speed. We already have 2.8, 2.81, 2.82 and seems 2.83 without fixing it.
Seems developers forgot that they wanted to turn 2.79 speed back before official release of 2.80. it needs to be fixed more then adding new features. Need to change it priority to high.

2 Likes
9

Without fast subdivision it is like going back 20 years. Ok Blender is free but productivity is much more important if you work with 3D.
I saw this: https://developer.blender.org/project/board/105/
Where are the open subdiv? Maybe better to throw in the towel, big disappointment …

10

Yeah I’ve been having this problem too and it’s very frustrating, but the problem is that even when I am running it it’s only using half of my CPU so it’s not that my CPU is slow

11

Apparently we should see improvements in 2.9, Pablo mentioned a huge improvement in subsurf on the last blenderToday live: https://www.youtube.com/watch?v=Pj8nF8m7gDw (min. 32:04)