Max render to texture lighting map bug

[Zeta]

After to searching for a way to quickly bake lighting on my models a friend of mine eventually wrote me a quick script that creates AO maps simply, which works great. However, sometimes doing rendertotexture > lighting map produces a nicer render, or one with more definition in it, so i sometimes render out a lighting map as well. I seem to run into a problem everytime i do this though - lighting data seems to always be missing or less defined on one part of the render than on the rest, producing an inadequate final output.

Here is an example:

You can see that there is a single skylight in the scene, centered and placed directly above the mesh. 80% of the output on the map looks great, exactly what i wanted, but some of it seems just not be receiving the same lighting as the rest. You can see this clearly on the left portion of the top of the dome - the shadows in the recesses abruptly change to a lighter tone.

Does anyone have any clues as to how to stop this from happening?

cheers

[-HP-]

Maybe increase the samples / rays, and decrease the distance / scale of the AO generator, don't you have any settings to mess with on that plugin?

I use XSI, and generate my AO's on it as well, so I can't be of much help.

[Wunderboy]

It can sometimes be down to your UV map and not having vertices welded together.

[Buddy]

Yeah what Wunderboy said.