Hi there, I have an issue with transfer mapping that I'm hoping someone may be able to give some advice on. I've been modelling a defibrillator for what will possibly be an educational game for mediacal students. I've modelled and and textured it fine except for one thing:

I edit my UV maps in an attempt to create as much space as possible but when I then transfer a high poly mesh onto the low poly it goes very wrong. It ends up dark grey and black and looks nothing like the high poly mesh.

However, when I just click automatic mapping and then transfer map it works exactly as it should.

The problem with just doing this is that the model has 5 or 6 separate pieces each with an individual normal and diffuse map when I'm pretty sure I should have all those pieces mapped onto one file for diffuse and one for normal maps.

Any ideas why this could happen?




This is what it is supposed to look like but preferabley all on one file


Thanks for your time

This is a simple model so unwrwap it as you see fit(all pieces on one texture flat).You will then need to set the edges of uv islands to hard.This is important so you don't get weird seams after bake in low poly.And as i recall, one maya setting from baking options is not good for this method so you gotta find what's the good one.Maybe post your uv's too after you unwrap.

I found the issue with the transfer mapping. I checked the 'ignore mirrored faces' box in the Maya Common Output Tab when setting up my transfer maps. It doesn't look great but nothing a bit of photoshop can't fix. Im assuming it went wrong in the first place due to overlapping UV's (in order to try and save space). So feeling confident that I solved quite a simple issue I went on to UV the next bit... and it happened again even though I checked the Ignore Mirrored Faces box I've also tried unchecking it for that part of the model and messed about with some of the other settings but that didn't work . On the upside I guess I actually learned what some of those extra setting actually do



Here's the UV's that I got so far (I haven't UV mapped the rest of it yet)



Normals (looking rather bad)



and Diffuse



Sorry, the images are a bit large lol

Ok problem solved. I figured it might be due to the overlapping UV's in some way. After a bit of research it seemed likely that it could be. Turns out it was overlapping UV's screwing things up. For example the back section of the dial was underneath the UV's for the dial itself. So I went and pulled it down into a separate quadrant and did a low quality transfer map... It sodding worked!!!!

This brings me onto another topic in a way. The back section of the dial will never be seen in a game... ever. Would it be wise to delete it in order to reduce the polycount? Or when transfer mapping would the envelope try and calculate the negative space or do anything else strange?

I'll give it a go I guess...

Note: this prop is intended to be imported into a game engine

Hardly the most stunning image but it'll look alright in the end hopefully

you shouldnt have any problems if you remove any unnecessary back faces. If there's nothing to cast the ray upon, it simply wont.

Cool, I might go ahead and delete some unnecessary polygons then. Thanks for the responses I'll post up the finished model when it is done

Improvement. All the separate peices are now on one texture file. One diffuse map and one normal map. Epic winning! There are bits That didn't go through the transfer mapping process (at the time I thought they were quite low poly so no need to) so now they look flat but I'm just going to go ahead and make some low poly geometry for those bits and transfer map them with the rest of the model.

This may be obvious for some people but this is what I've found:

- Firstly when transfer mapping a normal map no UV's should be overlapping otherwise your model will look like ass like my earlier attempts did.
- Transfer map every part of your model even if it is a part of model that doesn't have a high poly count. you could probably lower the polygon count that little bit more. Also this stops parts of your model looking flat where the normal map has no detail within that section of UV space.
- From what I understand (although not tested yet) you can overlap UV's for a diffuse map

Here's my rubbish model so far