Why does softbody lag so much?

I’ve heard that blender has problems with ATI cards…
Whenever softbodies touch any kind of collider, it begins lagging heavily. Like 5 seconds per frame. That bullet demo did the same thing in real time, and blender uses bullet, supposedly. Is it smooth for people with Nvidia? Or anyone?

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It could just be you have a slow computer. what are the specs of your graphics card/ram/cpu?

I have a duel core with 2.16 gigahurts of RAM and my graphics card is an ATI Radeon 1600. I would consider it fast, but lots of programs have issues with ATI, not that it’s a bad type of graphics card. Is blender supposed to do softbodies in real time? (for example, clothes on a body with softbody applied? For me, that takes 10 seconds per frame or more. Cloth is unbelievably slow.)

Hmm… I have 1.4 Gigahertz cpu and the ati sapphire x1650, and it runs quite fast. Can you maybe post a .blend? how many vertices?

Here’s the file. It lags on my intel imac leopard.


Happyhappyfunfun.blend (164 KB)

Have you actually used the “BAKE” button?

I just downloaded your BLEND file and baked the simulation and I can scrub the frames just fine. If you don’t take the time to bake the simulation, Blender is always trying to bake on the fly, and that might be the lag you are experiencing.

wait, of course baking it makes it go fast. I thought other people are able to just press alt-a and have their cloth/softbody flop around in real time. But does that blendfile work for you in real time before/while baking??

That’s a whole lot of collisions with very little room to ‘give’, and softbodies weren’t originally designed specifically to simulate cloth anyway, so—while they can simulate cloth—they also have to work through a more generic framework, which takes even longer. You’d probably get better and faster results using the cloth solver specifically for cloth simulations like that, but either way you do it, it’ll still be slow to calculate at first.

No, it chunks on my machine. But after baking, smooth as silk. That is why the button is there. And what is great about baking, is that it remains in tact even after you close blender and re-open the scene. You can even copy the blendcache folder along with the scene to another machine and skip the baking part altogether on the new machine. Blender will detect the cache and use it if it is in place.

Last time I checked (please forgive me its been a while since I did this research) - ATI cards are more powerful, but the drivers that have been created for them puts them down a few notches. Nvidia has wonderful drivers created for them, but don’t have as much power as ATI cards do (all depending on the card of course)

I have two computers, one laptop with an ATI and a desktop with Nvidia. Honestly I wish ATI had better drivers but thats how things work out.

And as far as baking goes - I love it. It is a recommened tool

But it’s so easy to accidentally delete all the frames in the cache (un-un-doably).

Wait until you start playing with fluid caches. 12 hour bakes and mulitple gig caches.

Sometimes you need to delete the cache manually (accidentialy). Especially with particles. they are so damn flaky.

correct me if i’m wrong, but aren’t there problems with blender and macs?

scrambled egg with a tip of cream on it…
Let us sort things:
1rst ATI cards work more or less fine on OpenGL
2nd that is the game engine uses bullet … the soft body module uses some home grown completely nuts model designed by some completely mad physicist
3rd that completely mad physicist was focusing on doing things as close as possible to a ‘general soft body engine’ … well … that’s why it has a incredible complicated user interface ( no, the true reason was to give all the users a hard time … you know he is a sadist … like your maths teacher )
4rth the file you uploaded performs pretty nice here ( about 0.7 secs per frame ) regarding, you did ignore any DoAndDoNot rules for ODE solver systems concerning mass spring systems.
5th Did you ever wonder why Demos / Ads show things as positive as possible ?
6th miracles are planned for Blender 3.8 :slight_smile:

I think the coder of the softbody system is a brilliant one, who has constantly improved the results and the interface of the system.

Just my 2 cents … Thank you!

im on a mac and i do not notice any problems with speed though i am using and 8 core mac pro not sure how much of a difference it would make