domingo, 19 de abril de 2015

UV Texturing: A Problem and A Solution

These days there's been a lack of entries in my blog mainly cuz i'm spending my time developing my demo reel and mainly cuz i want to meet the final deadline of the CG Student Awards 2015.

My intention is to present a short cut of say 2 or 3 seconds but caring about all aspects of CG and after, show the breakdown of everything. It will be a pirate shooting a ship cannon, there will be particles, characters, hard surface modeling, compositing and.... texturing!

Yes the problem i faced i want to talk about now is making the uv's of my cannon. I mean, i could just have done automatic uv's with mudbox but i wanted to follow the same process as in videogames and what the hell , i wanted to learn how to make proper UVs!

For this, i had my cannon finished and i exported the base mesh without smoothing/subdividing it to an OBJ file in order to be imported in UVLAYOUT 2.06. The UVs are always made in the low base mesh resolution.

Well, i started working in the uvs, it was a lot of work since i handmade all the uvs of even the tiny nails. And when i got to the point where i wanted to export my model with the uvs if found what i thought was a big problem: Headus UVLayout 2.06 exported all in a single mesh, despite the fact that it can read and load an obj with groups of meshes.

So what a problem i thought, since i wanted to be able to maintain the groups of meshes to work easily when texture painting and giving highest resolutions to different parts of the cannon. I really though at first i had wasted a lot of time.

The first thing to clarify was if the problem was effectively from the Headus UVlayout 2.06 tool. Navigating through the forums of UVLayout i found exactly that from version 2.07 up until the current they added the functionality to export an obj with several groups of meshes!!. Well from now on i will work with Headus  UVLayout 2.08 if i can.

Now the problem was still there: how to transfer the uvs from the obj with single mesh to a multimesh object with no uvs.

The answer again was in the internet. In Maya there is a tool called "Transfer Attributes" which can do just that: it transfers the properties of a mesh to another, i was still a bit skeptical since one obj file was all packed in a single mesh and my Maya cannon original low res file was grouped into different meshes, so not quite sure it would work.

I opened my Maya file with the low res grouped into meshes ship cannon and i imported the obj file with the UVs. Selected both, did "Transfer Attributes" Options, checked "UV" and applied..... And it Worked!!

Now I have at last, my model separated and grouped in different meshes all with the same UVs i had worked!!!. Now I can proceed to Mudbox and start painting!!!