I’ve got a placeholder vehicle mesh that I’ve made in Maya 2015. It’s one piece of geometry that was mirrored and then merged. It’s now one piece of geometry and a skeleton (for mount points mostly.)
It mostly works, but I’ve noticed that it’s messed up materials wise. On import, I’ve checked “Preserve smoothing groups” - which says in its help "If checked, triangles with non-matching smoothing groups will be physically split."
Now, unlike Max, Maya doesn’t allow you to explicitly set smoothing groups, so I can’t just remedy whatever is happening here.
If you look at the image below, you can see something of what happened. The grey band on the nose of the ship is the windshield, which has “windshield” material. The rest of the vehicle is supposed to be in a blue material, but as you can see it’s only applied that material to the first part of the vehicle after export, with some weirdness like 2 polys above the windshield not having the material.
Now, here’s what it looks like in Maya before I export it. According to Maya (and the exported FBX), there’s 3 materials - the blue, the windshield and the default material. There’s only one smoothing layer.
And here’s what it looks like in UE4, with 3 different materials applied (2nd material isn’t visible since it has no polys. Still imported and put in the list though!)
As you can see, it’s broken the mesh into 3 chunks. AFAIK it should be ONE chunk. Sure, there should be 2 different materials, but this is a merged mesh. At worst, it should be 2 chunks. (Windshield and the rest.)
I’ve briefly looked in to the FBX import code and I’ve looked through the FBX ASCII. No idea why this is happening.
So, how do I diagnose this problem? It seems like this is Maya’s fault, but since Maya seems to be the primary tool that Epic supports, I think UE4s importer should work around this. Either that, or Epic should write their own FBX export to avoid this.
Any feedback from artists or devs on how to work around or fix this crap would be very much appreciated. I’m a currently solo indie engineer having to make his own placeholder models. I’m only marginally competent with Maya, and according to it, everything is fine here.
