Mass FX questions

Danielmn

Hey guys,
doing some collapsing and cascading rock projects right now and hitting a few snags, wondered if I could get a little help.

My major problem seems to be having a object that I hav dissect into cuts and pieces.
I am really just looking for the the object to fall and obey gravity and hit the ground

But I seem to have a problem with it exploding right off the bat.


If I set the overlap collision to high I get a lot of objects falling thru the ground or have the objects compress to much to be anywhere to believable



Right now my only work around is to split the object into several sims so I can define collision detection for a certain group, but this takes a long time. Any thoughts

using 3d max 2012 ad mass fx


here is a sequence i have been working on. This two about 2 days with very little else going on.

monster

They are exploding outward because they are touching/intersecting when the simulation starts.

Have you tried unchecking "Collide with Rigid Bodies" in the MassFX modifier? If you do that the objects will only collide with Static Bodies.

If you want to uncheck that for a bunch of objects you can select them and run this line of code in the listener:

for obj in selection do obj.MassFX_Rigid_Body.CollideWithRigidBodies = false

Danielmn

thanks monster

that kind of helped in my test it worked

but in the final scene it did not.

It seemed to work better though, with that turned off and the collison mesh deflated by 10 %

have to do more testing had to move on too some other portion but will try again soon.

thanks again

Danielmn

Hey man
so i played around more and the collide with rigid still ignored static mesh

but i made a comprimise and did a very lo collision detection on the smaller particles

and the few larger pieces i did a more accurate collison mesh still deflated but got it handled better but there got to be a better way

Danielmn

here is an update on the sim that i described above

tharle

have you considered using PullDownIt? its a plug in for max that does rigid body collisions really well. the simulation part is free but the fracture tools you have to pay for. i've not used mass fx (still on max 9 and reactor) but it's much better than reactor for rigid body stuff imo.

http://www.pulldownit.com/

another thing you could try (although this is again reactor rather than mass fx - although i'm sure it's similar.) is just creating slightly scaled down collision objects for the pieces. that way they wont intersect but will still simulate reasonably accurately. hell i guess you could just scale all the pieces in the sim and then scale them back up afterwards. once you've added a bunch of dust pfx and played it back in realtime you wont notice that some of the pieces either dont touch or intersect.

Danielmn

tharte
thanks for the input I will look into that.

That idea is very similiar to what I did

I knew I would not have time to do a nice colision mesh for each object

so I scalled the tiny pieces do to like 50 %, so those guys almost past thru each other.

then I scalled the larger peices down about and average of 30 % and adjust a few mesh here and there, since there were only about 50 of the larger ones, it was reasonable to change by hand.

That is what you see above came out pretty will post a vid soon.

I still had some issue with mass fx after the thinged baked with the gizmos but that something else entirely.

kewlmack

hey,i had the same problem too where my fractured column explodes in all direction when my intention was to make it collapse to the ground....i still have my "Collide with Rigid Bodies" on,to simulate realism.what i did was decreasing the Rigid Bodies > Substeps to 0,and it worked like magic.give it a try