Instanced Rigid Body modifiers and shapes

[MarkAldred]

I'm fracturing a mesh using the voronoi script, selecting all the fractured fragments and applying a MassFX Rigid Body modifier. The modifer is applied as an instance to the multiple objects. I've seen this done in a tutorial, but whenever I do it, the physical shape doesn't conform to each mesh. It looks like it's instancing the shape from only one of the fragments and playing the simulation just blows the meshes apart like an explosion.

I have the modifier set to Dynamic and Shape Type to Convex. Checking 'Generate Shape Per Element' in the Scene Settings doesn't seem to have any effect.

Am I doing something wrong or in the incorrect order? At the minute I'm stuck with applying the Rigid Body modifier to each fragment. This isn't going to be feasible with a large amount of meshes.

Thanks

Mark

[MarkAldred]

PS Also, settings are not sticking. I had one simulation set uip so a column collapsed perfectly. I saved and closed the file, reopened it, and the column is back to exploding like a bomb hit it. I can see that the physical shapes have been scaled up in the viewport and regenerating them fixes it.

I tried resetting XForms with no success.

I forgot to say, I'm using max 2014 SP3.
Thanks.

[VishnuR]

I don't have much experience with Voronoi Fracture as its a 3rd party script not made by Autodesk.

However here are some tips:

Try converting objects to Editable Mesh or Editable Poly before applying Voronoi Fracture to them.

What happens if you use Copy or Reference instead of Instance?

I tried with simple sphere.

First Selected one single object > applied Fracture to it.

Then "Set Selected as Rigid body"

Simulation was good, objects collide based on actual shape.

Then selected above Fracture objects >

Shift Move and Copied items. All works great.

If you are still having problems perhaps attach a small sample scene reproducing

your issue so we can analyze further.

Also note am testing with Service Pack 5 for 3ds Max 2014

Best Regards

VR

[MarkAldred]

Hi Vishnu.

Thanks for the help.

I've attached a couple of files. 003 is the raw meshes and 004 is done up to 5 on the list below and saved.

1. select all and Set Selected To Dynamic Rigid Bldy

2. play simulation - column explodes rather than collapses so ....

3. set Contact Distance and Rest Depth to 0

4. still explodes a bit so set Substeps to 0

5. simulation perfect

Then the problems start ....

6. save and close file

7. open file and try selecting a mesh - the Rigid Body shape has grown in size and doesn't fit the mesh

8. in the MassFX Tools some settings have returned to default - Substeps are back to 3

9. even if I uncheck Use Ground Collisions, it's back to the enabled state when I reopen a file

10. the simulation doesn't work unless I either go through all the fragments individually and Regenerate Selected or reset Mesh Type to Convex in the MassFX Tools

I'd like to know why the MassFX shapes are not fitting the meshes after reopening the file. I'm not sure of this, but it appears that the MassFX shapes grow with each save! I'd also like to know why the changes I make in MassFX Tools revert after saving and reopening a file.

Thanks.

[VishnuR]

Greetings,

I can definitely reproduce your issue above with attached scenes.

Interestingly , if I export entire scene as FBX, import that back into new empty scene
then resimulate it works good. But on saving and reopening this newer max scene same issue
recurs on reopen: Selecting each mesh shows a much larger scale has occured on each Rigid Body shape.

I have logged this with our 3ds Max engineering team and will update you on any significant findings.

If its something that needs to be fixed, we'll have to wait until its fully addressed.

Thanks for taking the time to report this.
VR

[MarkAldred]

Thanks.

Please let me know if you find a solution.