SmallLuxGPU v2 Voronoi Fracture and Shatter Tests

[paco]

Fantastic test - really impressive result.

[SATtva]

Andrew Price wants it in the Blender trunk NOW.

[A-man]

That video if incredible! I especially like the panes of glass, it shatters so cool!

[luxRoot]

Rayfire? pffff lol wut

Amazing!

[B.Y.O.B.]

btw., just an idea - maybe Mango could make use of these tools?

[Chiaroscuro]

btw., just an idea - maybe Mango could make use of these tools?

Given how slowly I'm (not) working on this hobby project and how much I have left to do, their timeline is too tight.

[B.Y.O.B.]

Yes, they'll have to come along without your awesome project...

[A-man]

How do you set up the physics of your voronoi shards? I used another method to generate the shards, but I can't seem to configure the physics settings of the shards to get realistic collisions and friction as seen at 0:56 in that video. Also, many of my shards will go through each other and the floor object so in the end only about 60% of the shards are still visible, the rest go straight through the floor. Maybe if you could give me a screenshot of your rigid body setup? Did you use any python to do anything? And what scale do you use for the objects? I usually use standard scene scale, so my original object is maybe 2 or 3 blender units wide, and the shards are probably 1/15th of that.

[SATtva]

Maybe if you could give me a screenshot of your rigid body setup? Did you use any python to do anything?

Yes, this was achieved with the special-purpose code.

[Chiaroscuro]

Hi A-man, I'm using a standard Blender build, standard physics settings and standard Blender game engine to run the simulations.
I am using my own tools to, amongst other things, create the voronoi shards, calculate the mass and center of mass of each shard based on their volume and material density. My tools for Blender are not finished, still a work in progress, but I did release the source code to create voronoi shards (and calculate their mass and center of mass) for Bullet Physics. That source code is now included with Bullet Physics Library since v2.80.

Physics settings: beyond having correct relative mass and centers of mass, the only setting, and maybe single most important setting is that all rigid bodies are using collision bounds, without exceptions. Also I never use Triangle Mesh bounds, only primitives or convex hulls, so I break down non-convex objects into compounded convex hulls (convex decomposition).

Floor: Unfortunately Blender doesn’t implement Bullet's "Plane" primitive collision bounds, so your floor should use "Box" collision bounds, it must have a good thickness to be solid, and it must have a margin, typically 0.04; otherwise objects will fall through it and/or not have stable collisions.

Scale: Bullet Physics is comfortable with meters. Standard Blender scale is treated as meters, which is ideal, but you don’t want to use objects that are too small. If you want to use a smaller scale, you should increase gravity and FPS instead.

It helps to understand Bullet Physics to best use Blender's rigid body physics. This would probably require an in depth tutorial, and there may already be some out there, but all I can really suggest is to read the Bullet Physics Library manual. Problem is that it's a little too technical and targets programmers, not end users.