MEL scripting and tools development

I recently wrote a tool that allows our artists to use Maya as a level-design tool, rather than the Unreal editor. This was critical for our environments: due to the modular nature of our level geometry, we have a very high standard of precision for our geometry placement, especially our collision geometry.

The Unreal editor has no vertex-snap movement setting, so we had to layout our levels in Maya, export the scenes via COLLADA to Unreal, and place all of the scene's geometry as it was in the Maya scene. This proved to be incompatible with Unreal's AI pathing and "Kismet" building.

The consequence was going to be that each piece of level geometry would have to be centered at the Maya origin and hand-placed in Unreal, as close as possible, by eye. It would have taken weeks and been a QA nightmare to boot, due to the collision problems.

My script allows artists to lay out the levels as they desire, in Maya with its superior rotation and snapping tools, and then run my script, which leaves the Maya file looking the same to the artist, but when exported, the geometry is seen by Unreal as though it is centered at the origin, allowing our builds to work again.

A couple of code samples:

We also had a problem with our ground tiles having very noticeable lightmap seams. This was because the UV channel used for lightmapping was a simple planar-projection from top view. Since the tiles were perfectly square, the 0-1 space was filled edge to edge, and the seams bled.

I wrote a script that went through the 1000+ tiles and re-planar projected the lightmap UVs, then gently scaled them down by 3% so that enough buffer space exists to prevent the lightmap seams. The automation of this task saved us a week of very tedious work.

The code: