Collision Of Objects Already Penetrating At Start

[liu_0083]

1) If I want to break the wall above with an object, how can I prevent the bricks from penetrating each other as there must be some bricks already do so at the start frame because of the few degrees of random rotation and translation. Or must they be separated at the start frame ?

2) Actually the simulation is slower than I expected even though I pick "implicit box" and the volumn detection to 2,2,2 already. Is it possible to make the display "inactive" for faster simulation, or just simulate throught command line ?

Thx.

C.

[Ratman]

First off, you should switch collision detection from point based to edge based, that should prevent a lot of the penetration at start.

[liu_0083]

I've set it to edge-based.

The penetration seems to be unavoidable because I want little randomization while not seeing the gap between. So the penetrations do occur before simulation.

[aracid]

I've set it to edge-based.

The penetration seems to be unavoidable because I want little randomization while not seeing the gap between. So the penetrations do occur before simulation.

is it vital to have a stable RBD sim,

why can 't u just turn rbd 1 frame before u want to break it?

are u going to use the glue feature ?

If however u are looking for something that u dont need to key to "cheap fix"

u could consider using a stand in object that is more aligned, something more symetrical (with out the random rotation) and use that as ur proxy, then transfer that data onto your high res bricks.

this isnt perfect, however it should give u the look ur after.

would either of those two solutions work for you?

[liu_0083]

Thanks aracid.

At the mean time I have just watched the RBD dvd. I think the boxes should be small enough to prevent initial penetration and high-res brick with a little bit bigger size is used to prevent the gaps.

After that, say I'm going to make a door space in the wall, using "cookie" after the copy sop. But I found that the intersecting polygons is generated as one group, not with the brick it cuts. So in the simulation this group falls as a whole object independently. Spenting some times testing but have no solution yet.

Here is the scene demostrating the problem. regroupIntersected.hip

Edited February 5, 2007 by liu_0083

[aracid]

hope this fixed ur problem

regroupIntersected.hip

a couple of things,

when u made ur group in your copy sop, u werent specifying that u only wanted to have that group in ur RBD, so essentially it was effecting everything that came in. including the group u made in ur cookie.

in my solution, i dont really bother about the groups made up the network, i just create a group after the cookie using the connectivity and partition sop, that basically groups all the connected primitves. giving u a cleaner solution, specified in the DOPS that I only wanted to use that group.

[liu_0083]

Oh yes ! Just remember the great usage of these two nodes once u mentioned it.

Thx a lot.