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View Full Version : mdd,bullet, fracture help....i'm totally stumped



nikfaulkner
08-20-2012, 11:08 AM
ok i have an object that falls from the sky and shatters into thousands of bits. i did this with fracture and bullet then baked out and mdd. this is working well.

i need to have an un-fractured version of the object to render so i can swap between the 2 versions (to avoid the cracks and artifacts in the render)

i tried, using bullet with the same settings....its close but doesn't match exactly.

i tried parenting the unbroken version to the mdd, with dponts "node item notion" and "point info" again very close but the rotation was off

i tried parenting the unbroken object to the broken version, then run bullet. the unbroken object just gets left behind and is ignored by bullet.

....anybody any ideas, other than animating the unbroken object by hand on every keyframe to match the broken version with the bullet physics?

dpont
08-20-2012, 11:20 AM
ok i have an object that falls from the sky and shatters into thousands of bits. i did this with fracture and bullet then baked out and mdd. this is working well.

i need to have an un-fractured version of the object to render so i can swap between the 2 versions (to avoid the cracks and artifacts in the render)

i tried, using bullet with the same settings....its close but doesn't match exactly.

i tried parenting the unbroken version to the mdd, with dponts "node item notion" and "point info" again very close but the rotation was off

i tried parenting the unbroken object to the broken version, then run bullet. the unbroken object just gets left behind and is ignored by bullet.

....anybody any ideas, other than animating the unbroken object by hand on every keyframe to match the broken version with the bullet physics?

BDD Scan from DP Motion Designer can export a BDD File
which can be read by HardFX, then you may try to export
the path of one part and see if you can use it
for motion of the unbroken object before shattering,
but the motion needs probably to be shifted
for matching object pivot.

Denis.

SplineGod
08-20-2012, 04:16 PM
You also might try using editfx on the mdd file and extract a motion path from a point. You can also use dponts suggestion but also try using editfx on the bdd file to do the same.

DigitalSorcery8
08-20-2012, 06:51 PM
Not sure if I understand this correctly, but why can't you render the uncracked object up until the point of breaking (like frames 1 to 200) - at that frame render the other scene from that point on (like frames 201 to 400) - then edit together?

nikfaulkner
08-20-2012, 06:57 PM
Unfortunatly softfx won't load the mdd, it gives some error message (not in front of my computer so can't be more precise)

There are only 3 frames at the beginning of the sequence where bullet
Isn't controlling the physics. The fall trajectory is all bullet as well (it's not a straight drop, it has some z motion as well)

BennyB
08-20-2012, 07:42 PM
1) take your parts object switch from parts to rigid.
2) run bullet.
3) use the lscript: MFMotionBaker.ls and bake it.
4) copy motion to unbroken object with same pivot point.

I did a quick test with a broken box that was falling on the x,y, and z and a duplicate layer of the box that was baked in rigid mode and unchecked bullet and the two layers are exactly the same before impact.

dpont
08-21-2012, 12:06 AM
...I did a quick test with a broken box that was falling on the x,y, and z and a duplicate layer of the box that was baked in rigid mode and unchecked bullet and the two layers are exactly the same before impact.

If you can get the same animation in rigid mode
with the unbroken object, then run BDD Scan
for one-piece object it can export the motion file
or overwritte the motion.

Denis.

nikfaulkner
08-21-2012, 12:08 AM
1) take your parts object switch from parts to rigid.
2) run bullet.
3) use the lscript: MFMotionBaker.ls and bake it.
4) copy motion to unbroken object with same pivot point.

I did a quick test with a broken box that was falling on the x,y, and z and a duplicate layer of the box that was baked in rigid mode and unchecked bullet and the two layers are exactly the same before impact.


in the xyz maybe but not in the rotation channels. i'm just about to give dennis's original idea a go. i'll let you know how i get on...wish me luck

nikfaulkner
08-21-2012, 01:08 AM
yep, using bdd's got me close enough. I had to tweak a handful of frames but it was very close. I used the exported .mot file on a null then parented my un-fractured object to that. it made it easier to tweak rotations on the object without screwing up the overall motion.

thanks for your help guys, and hats off to Denis for plugins that save the day yet again.
:)

n