No way to get models from SketchUp to UDK properly?

[DasMatze]

I've been modeling and mapping for the Source engine and using SketchUp for years and wanted to go a step further after the Source engine hasn't met my expectations for a long time. Now I'm looking into UDK.

Unfortunately the start I had with UDK was pretty rough. After three days of trying out countless file formats, export plugins and converters (including HardPCM's export plugins), I still haven't found a way to get models into UDK that have a custom collision mesh as well as working smoothing groups.

With many file formats SketchUp (or the export plugins) not only added empty groups/meshes to the exported file but also changed or replaced the group names. Therefore I have not been able to create any collision meshes with the UCX prefix, even when I corrected the group names in the exported files (when the files were editable with text editors). UDK simply interpreted them as generic meshes. If only there was a way to import collision meshes (and additional UV maps) from other files ...

Only one plugin, an ASE exporter made for RollerCoaster Tycoon 3 modding, kept the names of the groups and exported the correct amount of groups. However these ASE files were also the only file format where the UDK decided to smooth every corner of the model which makes it useless.

So, is there really no way to get models from SketchUp to UDK with no loss of valuable geometry information?

[darthviper107]

Have you tried using the standalone FBX converter? It allows you to load files and convert them to FBX if your program doesn't have an FBX exporter.

[DasMatze]

Yes, I did. Thanks for the help! Funnily right after posting this I found one way to get them correctly into UDK by exporting them to OBJ, importing them into Milkshape3D, fixing up the names (I did this in a text editor before) then exporting them as OBJ files and converting them via the standalone FBX converter.

To test this method, I created a simple test object with one mesh, two collision meshes and some smoothed edges. Now I have a different problem: the collisions don't work as expected. I named the model "A" and the collision meshes "UCX_A_1" and "UCX_A_2" but I only get this:

which is completely wrong, as the collision meshes are one box and one half cylinder. The red part (which should only be the half cylinder) shows the convex version of both collision meshes combined.

I tried creating two base meshes so I can name the second collision mesh "UCX_B" as well as moving the second collision mesh away from the first one (like the documentation suggests) but it didn't change.

[darthviper107]

I believe you can import collision meshes separately from the static mesh, you import your static mesh to UDk then open it from the content browser, I think in one of the menus there in the Static Mesh Editor window there is an option for importing a collision mesh.

That way you wouldn't have to worry about collision mesh naming.

[DasMatze]

Nope, I don't see anything like that. It's what I had expected but you can only import LODs.

[JessieG]

Try changing the numbers at the end of the collision names be "01" and "02" not just 1 and 2.

[darthviper107]

Nope, I don't see anything like that. It's what I had expected but you can only import LODs.

Maybe I'm wrong. I do know though that you can have it automatically generate a collision mesh

[online|offworld]

yeah I always just use the collision mesh generation in the static mesh editor?

[DasMatze]

The collision mesh generator is nothing I want to rely on. It's very imprecise and you have to waste precious polygons to cover the most basic concave solids.

I tried using "_01" instead of "_1" at the end. It worked with another test model:


But the other model is acting strange again. It has only one collision mesh:

... and that one mesh isn't even one of the collision meshes, it's the one you're supposed to see.

[fdslk]

To add your own made collision meshes, you must model them in your software, name it the same as the mesh you want to import, adding the prefix "UCX_"

Example:

Mesh to import: BOX01
Collision for the mesh: UCX_BOX01