Slow physics

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Slow physics

Post by slowtiger » Wed May 01, 2019 11:33 am

Just a gentle reminder: if you use physics in your rigs, the project will render on 1 core only, thus extending rendering time a lot.
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Re: Slow physics

Post by Greenlaw » Wed May 01, 2019 3:47 pm

Just curious but is that still the case when you enable Use Baked Physics?

To me, enabling this option should suspend physics processing so Moho can use all processors for normal keyframed animation and rendering. I haven't actually checked for this though. If it still renders on only one core, this might be a bug.
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Re: Slow physics

Post by slowtiger » Thu May 02, 2019 9:17 am

Good point. Can physics be baked in v11?
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Re: Slow physics

Post by Lukas » Thu May 02, 2019 12:47 pm

If you bake physics and let it play out it will create a lot of keyframes. If you then turn physics off, I assume you can render on all cores again.
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Re: Slow physics

Post by Greenlaw » Thu May 02, 2019 3:56 pm

slowtiger wrote:Good point. Can physics be baked in v11?
I'm not sure. I don't have 11 on my laptop or at work, just 12. I'll check on my workstation at home when I get a chance.

In 12, the option is here:

Image

For bone physics, you'll need to bake the bone channels with a script. (IMO, this really should be a native feature though.)
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Re: Slow physics

Post by slowtiger » Thu May 02, 2019 4:22 pm

It was, in fact, bone physics. (Result here: viewtopic.php?f=8&t=32856)
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Re: Slow physics

Post by synthsin75 » Fri May 03, 2019 12:18 am

Yep, you can bake the physics in v11.2.
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Re: Slow physics

Post by Greenlaw » Fri May 03, 2019 12:40 am

Just a little more info for anybody who can use it:

For the bones stuff, the bones animation will need to be baked and then bone dynamics switched off. Naturally, this should be done to a copy of the scene in case you need to re-calc with different sim settings.

IMO, it's probably not worth the trouble unless you're seeing a significant hit in render times. Or if you're using network rendering, in which case baking dynamics may be the only way to get correct results when rendering across multiple computers. (This is the case when I'm using dynamics for 3D animation and VFX work in other packages anyway.)

Here's a forum thread for a Moho bone baking script:

https://www.lostmarble.com/forum/viewto ... 32#p173732

(Note to the Moho Developers: baking tools like this really should be native.)
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Re: Slow physics

Post by slowtiger » Fri May 03, 2019 9:10 am

Greenlaw wrote:For the bones stuff, the bones animation will need to be baked and then bone dynamics switched off.
Whoah. I've got a character rig with 9 bones all doing physics, multiplied by 6; that's 54 bones - do I have to select each and every single bone after baking and switch physics off? Wouldn't it be possible to use a script, point it to a folder and say "switch off physics on all bones inside"?

The more I work with stuff like this (and not only in Moho), the more I feel the need for filtered selections.
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Re: Slow physics

Post by Greenlaw » Fri May 03, 2019 2:37 pm

You should be able to globally disable bone physics from here:

Image

I recall having some issues with it back in 9.5 or 10 which I think got fixed, but should probably check it in a later versions.

Hmm. The big question I have at the moment is: does this switch disable bone physics for rendering? How about when I'm using Moho Exporter?
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Re: Slow physics

Post by synthsin75 » Fri May 03, 2019 10:37 pm

Greenlaw wrote:You should be able to globally disable bone physics from here:

Image
Like frame skipping, that's only a workspace setting.
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Re: Slow physics

Post by Greenlaw » Sat May 04, 2019 12:56 am

Ugh...I was afraid of that.

Does selecting all bones and then checking off bone physics in the Bone Constraints panel do the trick?

I could check myself but a bit busy at the moment.
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Re: Slow physics

Post by synthsin75 » Sat May 04, 2019 1:27 am

Greenlaw wrote:Ugh...I was afraid of that.

Does selecting all bones and then checking off bone physics in the Bone Constraints panel do the trick?

I could check myself but a bit busy at the moment.
Yes, except that it would also make all other constraint properties the same.

Turning off dynamics for all bones on a layer or the whole project sounds like a task for scripting.
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