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custom collision mesh on custom static mesh

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    custom collision mesh on custom static mesh

    Hey everyone,

    I've looked at the udk video tutorials in the official documentation but it doesn't seem to cover much about importing and assembling you're own custom-made assets. How would I go about creating a custom collision mesh for my object which i've imported as a .ase file? Is there a way to make the collision mesh in my 3d package and import it in? I wouldn't even know how to make one with the builder brush in udk, but I'd imagine it would be quite difficult for an irregular collision mesh.

    I'm new to udk and game engine editors in general.


    In a nutshell, without explaining all the options - you can export a custom collision model with your original mesh you made in your 3d modeling package (within the same .ase).

    For simplicity, let's say you modeled a bench. The bounds of your bench resemble a large rectangular object. In your modeling program, you would have named your bench a unique name, such as "WoodenBench".

    Now, if you wanted to make a custom collision model for that bench, you would model a large rectangular box around the bench to cover the collision hull. However, you would name that rectangle "MCDCX_WoodenBench" - the "MCDCX" flag is recognized by UnrealEd as a collision hull.

    Now, when you export your model with the collision hull with ActorX, you will actually export the entire scene, and not selective to individual objects in your scene.

    When you import to UnrealEd, you can check the "view collision" option form the menu and see that your wooden bench would have been imported as normal, but also includes that rectangular mesh you made around it as a collision hull.

    There are numerous options and ways to import a custom collision hull. One thing to keep in mind is make sure they are always Convex, and contain no "holes". For more complex objects, use multiple simple shapes to cover your collision - but make sure they do not overlap in your modeling program.



      I don' know about 'MCDCX', but the documentation says UCX for convex Mesh, as seen here Program. And that works for me.

      Hope that helps.


        same here.. just 5min ago i exported UCX_something with my model and it works just fine..


          AWESOME! Thankyou so much guys! I couldn't figure out how to export a static mesh with actorX, however, then I just made a file with a prop and its corresponding collision mesh with the UCX prefix, and exported the entire scene with max standard .ase exporter and it worked just fine.


            hey im trying to export a fbx file with modular assets of various building pieces and they each have their own custom collision and they are all named with the "UCX_" prefix. however,after importing the meshes into udk the only static mesh that says it has collision is the solid wall piece,the plain box figure. are these the right type of collision models? i read somewhere they cannot be open,but all these meshes are closed.what do yall think?


              I did not play with FBX, instead i used ASE format. It is possible to export multiple UCX_ collision meshes for one visible mesh.

              Things you need to watch:
              - UCX collsion mesh should be convex, well UDK importer can handle slightly non convex shapes but you neet to check results after.
              - you can have multipme UCX meshes for single model, name them like this (for ASE I checked that, and this naming works): Box.ASE , UCX_Box.ASE, UCX_BoxA.ASE UCX_BoxB.ASE, UCX needs to be uppercase!
              - for ASE collision to work you need to select model and its all collision meshes (they all need to be exported to one file) and export selected. If meshes are exported to separate files UDK will not recognize them as collision meshes.


                the only thing with ASE format though is that i dont believe you can export multiple meshes in one round. yes,you said collision meshes but i mean different meshes altogether with their respective collision it possible?


                  1st. some of those collision meshes are convex, so they will not work properly. is for the L shaped one, you would have to use 2 boxes.

                  2nd. try the udk's auto convex collison tool - its in the collision menu of the static mesh editor - it works 95% of the time and will save you a lot of hassle


                    Hey guys, I've been trying the UCX_... and the MCDCX_ .... but when I import into UDK the collision goes beyond the extends of the actual model.