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Steve Green
06-02-2005, 08:50 AM
Hi,

I've been getting to grips with fracture recently and have come across a couple of snags

http://www.stephendgreen.pwp.blueyonder.co.uk/fracturetest.avi

if you look at the end of the animation, a small brick doesn't seem to be attached but it remains stuck in mid air. The collision tolerance seems to be OK so I'm not sure what parameters would prevent this.

The other snag is that I get some weird artifacts using Image Motion Blur (you can just see this near the brick at the end of the avi)

I'm guessing this is a problem with keys being created in sub-frames, I've tried the key-frame reduction but the fracture simulation just falls apart from frame 0.

Any ideas?

Thanks,

Steve
LoneRobot
06-02-2005, 09:06 AM
hi steve,

that's looking great so far! :thumbsup:

i assume the floating piece shows up in the preview so it's in the RB collection.

What i would normally try with things like this are -



check the fracture settings for the piece - its possible to set an individual piece to "Unbreakable" in the fracture rollout
check the piece has a mass applied
check it's not set to unyeilding
check the simulation geometry type isnt on anything it sohuldnt be (i dont think its this but it always pays to check)
check it is a valid 3d object (no duplicate faces, unwelded vertices etc...)
if its not any of these then i would do two things -

hand animate the piece down when the other bricks are falling - the shot is busy enough to hide it, or delete the fracture system and set all the pieces into the RB collection. Make the fracture simulated objects "unyielding" so that reactor keeps thier animation and simulate the brick as a RB. It should then react to the others like a normal RB sim. If it's still not behaving then i would snapshot the floating object, delete the old one and try again as a last resort.
Steve Green
06-02-2005, 10:29 AM
Hi Pete,

Thanks - I'm just trying to get it all working OK, then I'll transfer it into a real scene. The time consuming part seems to be the creation of the fragments - All the scripts I've seen only produce fairly simple fragments, and I'd like to get these ones looking a bit more detailed.

I think in this case it was me not paying attention - the proxy object causing the collapse hadn't quite cleared the fracture objects, so that brick was resting on it (just)

However, after fixing that, I got the same thing happening with a smaller piece and I checked all the things you mentioned, so I guess it's just one of those things that I can fix by hand.

What I did notice is that on the last frame I get errors about the simulation becoming unstable - but I'm not sure what is causing that.

Cheers

Steve
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06-02-2005, 10:29 AM
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