5 replies to this topic

[nMolson]

i Did a search and haven't found any info on the subject but it seems to be a common problem.. useing bullet rbds with fractured glue objects that start out in contact, when running the sim they just pop out or explode all together. turning off "polygons as convex hulls" seems to help but i cant get rid of the pop completely. many people in my class have had this same issue but we have found no real solution, it their one? or is bullet only suited for sims where objects dont start out in contact (ie fractured objects)

[dpz]

<bump>
yep, some info on that would be nice ..
</bump>

[nMolson]

dpz, on 02 July 2012 - 03:01 AM, said:

<bump>
yep, some info on that would be nice ..
</bump>

I found that glue constraint networks can hold back the popping but those can come with a whole new set of issues...  would be nice to know a proper way around the issue, assuming there is one

also some one just told me you can key your rigid body solver, could be useful to start in rbd and switch to bullet once things get moving

Edited by nMolson, 02 July 2012 - 11:19 AM.

[spev]

its to do with the collision objects intersecting on first frame......try adjusting collision padding or adjustment factor on rbd object or the penetration threshold on the rbd solver...if this does not work...try using an explodedview node in sops and explode by a small margin...this works to stop the popping and you may have to parent the origional geo to the sim to close the gaps.....hope this helps...

[nMolson]

I had used a foreach to scale each piece, pretty similar to your exploded view solution i think, and had played with the padding, never tried the adjustment factor, il give that a go, thanks

Edited by nMolson, 02 July 2012 - 01:32 PM.

[Netvudu]

This is a serious problem right now IMHO, and really uncomfortable. Obviously not a show-stopper, but it makes using bullet for fragmented objects a real pain.