Getting frustrated with collisions on imported geometry


I’ve pretty much finished prototyping my levels using the BSP, now I’ve been trying to get “down and dirty” (so to speak) and do more of the detailed level designs in either Maya LT or Blender. I’ve been learning them both, but I’m thinking I’m going to end up with Maya. I’ve been an Autodesk customer ever since 3D Studio R2. (Actually began using their products when it was just 3D Studio 4 LOL!) Anyway–To the point:

I’ve created a simple hallway section to import and test, and when I try to play it, I have no collisions–well that is to say the entire hallway is a collision. One big box around my entire mesh. Am I going to have to now go through and essentially design my levels twice (once with the geometry, and a second time for custom collision data?) If so, I’m really annoyed. There has to be a better option. I’d rather stick with the performance hit and build once with BSPs then have to create my level information, then go back through and recreate everything again as collision data.

Please tell me I’m misunderstanding something somewhere. This just doesn’t seem logical. Why can’t UE use my imported poly information as collision information? If I build it, naturally I don’t want anything to go through it. (Except for special occasions, and in those cases I’m more than happy to add special geometry.)


P.S. I’ve been searching for good answers to this for so long I probably could have had a whole game produced in just the time I’ve been trying to convert my workflow over to using external meshes…

Take a look at this video and choose one of the ways :slight_smile:

Thanks for the link! Unfortunately, I don’t have the luxury of the videos at the moment. But I will check it out as soon as I do.

If anyone has any good text references, or quick advice, I’d appreciate it as I really have been having a hard time finding anything textual even with the help of Uncle Google. And that’s more of an immediate need right now.

Hi ,

There are a number of reasons not to use the mesh as it’s own collision. Per Poly collision can be more expensive than using a simple blocking volume or simple box/sphere collision mesh.

For the majority of meshes you can create your collision boxes in the Static Mesh Editor with very simple geometry.

If you have more complex objects you can try using the Auto-Convex collision generation which will create a bounds around the mesh based on the number of Hulls and Hull verts set. This has actually been improved to be more accurate with 4.8

Also, if you need something more you can always create basic custom geometry when things in the editor do not meet your needs. (You can read about this in the documentation below).


Thanks! And the 4.8 Auto-Convex generation looks great!

Also, wanted to add that I totally forgot about the Hulls and Hull Verts. By tweaking these, I was able to get results that were satisfactory for me without having to recreate or add any new geometry. At least this will get me covered on most bases, then I can find the areas that need tweaking later and work from there.

Thanks again for your prompt replies! I’m impressed at the speed with which my queries were answered.