Creating Collision in Maya?

[Gateway]

Anyone have any info on how to create collision in maya, we have several hallways pieces we are modeling and want to know what the best way to create simple collision for these..

[Denny]

Create a primitive and name it depending on type;
Cube = UBX_*
Sphere = USX_*
Convex Custom Mesh = UCX_*

So a cube for example would be UBX_Cube or UBX_Floor.

[chrisrothcg]

If the geometry is simple enough, and closed (no faces missing on bottom or top), I usually just duplicate the mesh and rename it UCX_samenameasoriginalmesh.

[Crozz]

Does it have to be convex? Most of my collision models aren't, but they do work ingame. Are there some bad things that arise when they aren't convex?

[LordsWarrior]

Im interested in this also.

Im used to engines wher eI can bring in a large mesh and jsut tell it to be automatically collidale and just work.
I know its not efficient but its quick.

SO from maya if I have a mesh with floor an walls (like 5 sides of a cube) whats the best approach....split it into pieces (walls/floor?)

Chee-LW

[Denny]

You can make per-poly collision but it can bog down performance if it's too high poly, some things in the physics engine won't work well either.

Use these settings on your static mesh and you should have per poly collision.
http://forums.epicgames.com/attachment.php?attachmentid=329&stc=1&d=1257769657

[denrei]

Create a primitive and name it depending on type;
Cube = UBX_*
Sphere = USX_*
Convex Custom Mesh = UCX_*

So a cube for example would be UBX_Cube or UBX_Floor.

Just wondering where you come across these little gems. Unless I'm being an idiot, I hadn't seen that information in
http://udn.epicgames.com/Two/ActorX.html
http://udn.epicgames.com/Two/ActorXMayaTutorial.html

There seems to be many fantastically useful little things that I don't know... (i.e. being able to ignore some nodes in a maya scene :P)

Thanks!

[Lamont]

If you have a ton of collision prims, I made a script: http://digitalweaponx.net/files/LGUCXname.rar.

If you don't like the "_smesh" appended name, then you can mod the script, it's pretty easy. I just hate seeing things with default names pCube103Shape drives me nuts.

----------------
http://digitalweaponx.net/wp-content/gallery/scripts/ucx_rename01.jpg

The GUI is very simple, you type in the name of the mesh that the collision is going to be renamed for. In this case, I name it “sourceCube” and my shape name is “sourceCube_smesh”. The “_smesh” stands for Static Mesh. Unreal is a PITA when it comes to things being the same name, so best to learn to organize your UPK’s early.

http://digitalweaponx.net/wp-content/gallery/scripts/ucx_rename02.jpg

Select all the meshes in Maya that you want to rename, and hit the “Rename” button. That’s it. Do not forget to assign the same material as your base mesh to the collision volumes before you export. I reckon I could add that in the script to do it auto-magicly. Maybe later...

http://digitalweaponx.net/wp-content/gallery/scripts/ucx_rename03.jpg

[Metal3d]

Just as an addition to this topic, I had some previous collision models from UT3 that I imported into UDK that use the format "collidemeshname_MCDCX" for the collide mesh and they seemed to work well. I did not however have any success using any built in collision settings in UDK options.

EDIT: "Use these settings on your static mesh and you should have per poly collision."

Denny, I can't even locate those settings on my model, in any of the places it has collision settings - am I missing somthing?

[Norman3D]

If the geometry is simple enough, and closed (no faces missing on bottom or top), I usually just duplicate the mesh and rename it UCX_samenameasoriginalmesh.

Not a good idea, you will get lots of performance problems in the long run. If you duplicate the mesh and exported it as UCX, unreal will slice the mesh in several tiny boxes in order to preserve the complex silhouette. Try to open the staticmesh with the staticmesh viewer (double clicking the staticmesh in the content browser) and click on Collision/ 6DOP simplified collision. If that is not good enough, make a custom one in 3dsmax or Maya... but make it as simple as possible.
If your static mesh is essentially a wall, you might as well consider using blocking volumes in your level, and turn off the collisions of the static meshes, or switch them to BlockWeaponsOnly.