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Quick Create PhysBody - Convex vs. Static Mesh
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dominoe Offline
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Post: #1
Quick Create PhysBody - Convex vs. Static Mesh
Hi all, hopefully an easy one for yall -

(i love this feature btw)

I'll be placing lots of rocks (roughly 10k poly each) and I resize the mesh after placement for a bit of variety, then apply the 'Quick Create PhysBody' which seems to be working great; ie it does what you'd expect correctly.

Both the 'Create from Mesh as Convex (16 or 32 vertexes)' and '...as Static Mesh' seem to both be accomplishing the same result I'm looking for.

My questions are, which method requires fewer resources? And what exactly is the difference between the two?

Thanks in advance.
01-12-2011 10:55 PM
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Driklyn Offline
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Post: #2
RE: Quick Create PhysBody - Convex vs. Static Mesh
In World Editor, press View > Physical Bodies (or Ctrl+Shift+P) to view the physics.

Convex is for dynamic meshes (those that move) and Static is for static meshes (those that don't move).

16 and 32 represents the total number of vertexes that will be used to create the physical body from the mesh. The higher the number, the more precise the collisions will be.

Convex physical bodies cannot contain any holes, so if your mesh has a hole in it (a donut, for example), the physical body will not (meaning that nothing will be able to pass through that hole). If you wish to keep any holes, you must use Static. This will, however, force the mesh to be static (i.e. it can no longer move).

If you switch to the Model Editor, load in a mesh, then press the Physics tab on the right (or press 4), you can then click on the Physics button in the sub-menu and see all the available ways to create a physical body. Creating a Convex physical body this way allows you to have 16, 32, 64, 128, or Max vertexes.

In terms of fewest resources, I believe Convex 16 would use the least, followed be Convex 32, and then finally Static, although I may be wrong about this. However, it makes sense this way. The lower the amount of vertexes, the lower amount of hard drive space it will take to store the physical body and the lower amount of RAM it will take to load it.

Btw, 10k seems like an awful lot for a rock. It must be a very smooth rock. pfft
01-12-2011 11:49 PM
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dominoe Offline
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Post: #3
RE: Quick Create PhysBody - Convex vs. Static Mesh
Thanks for the explanation Driklyn, I appreciate the detail - Convex it is!

Yeah these particular rocks need to be north of 5k as they are large in the gameworld compared to the player (several times his size) and are intended to be walked on, viewed up close, and have details about them like cavities.

I'll experiment with lower poly counts of course but this particular method of making them leans heavy on polys... might have to find another way.
01-13-2011 07:00 PM
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