Stitching with limitations

[Anonymous]

Hello,

I am trying to make stitching on furniture with a few limitations and cannot seem to get the quality I am looking for.  The limitations include...

- Normal map size cannot be any higher than 1024, would like to stay at 512 if possible

- Poly count of piece has to be between 10k-20k 

- Am using map channel 1 and 2. Channel 1 is the diffuse and channel 2 is the normal

- Models are made to real world scale so stitching has to be very tiny 

- Would like to not exceed 3 normal maps but could be a possibility if necessary

- Must be JPG file format

Things I have tried.... 

- Baking high poly to low poly (512 and 1024 map sizes)

- Painting in Photoshop and then converting to normal map (512 and 1024 sizes)

- Modeling the stitching and  then putting a path constraint along a spline (causes memory issues and poly count issues)

Any suggestions or ideas would be greatly appreciated !

Thanks

[jon.bell]

Hey Dan,

Thanks for your questions here. The biggest issue you're facing is that it's tough to go beyond the limits of your bitmap texture size and poly count restrictions. What you're describing are assets well-suited for games (or long shots in high-res CG scenes), but they're not going to hold up under high-res closeup rendering.

That said, I think your current approach is fine, and your test renders look good given the above constraints. You could create high-res bitmap textures (like 2K by 2K), shrink them down and sharpen them in Photoshop. I also think that you might try to find a "sweet spot" between your poly count and the size of your bitmap textures -- instead of 20K polys and 512K texture, I would shoot for 10K polys (maybe even 5K) and increase the bitmap size to at least 1K or maybe more, if you can get away with it.

May I ask exactly what these models are for? I'm assuming they're for a real-time environment, so you may have memory restrictions, but from what I can see, you're already on the right track.

Please let me know if this information helps, and if you have any other questions I'll do my what I can to assist you.

Best regards,

Jon A. Bell

Autodesk Technical Support

[Anonymous]

Hey Jon,

Thanks for Your quick response !

After writing this and realizing a few things, I found out we will not even be able to use normal maps for the stitching. This is because the stitching will need to be able to change in color. 

Yes, you are correct, this is for a real time environment and has some memory limitations. I know we are okay to use 10-20k worth of polygons per model and we have tested using higher resolution normal maps. It increases the initial load time  by a little bit and maybe could cause issues later down the road. We also have tested using 2k textures for our fabrics and we got the same type of result, great resolution obviously, but increases the initial load time.

Where we stand right now with our project is still trying to figure out a feasible method for the stitching. I tested one other method which was detaching loops of faces close to where the stitching would be, put a UVW map on it and set it to face so each face has one thread. From there you could change the size the thread by scaling the UV's. The issue I tan into with that was the stitch was rotated 90 degrees on random polygons and was not consistent. Another issue I found with that was this would mean the polygons where the stitching would be would have to be pretty uniform because the size is dependent off of 1 UV tile.

Conclusion, I think the best route to go with this type of thing, where the stitching is so tiny and many restrictions, is to somehow have it in the diffuse. I am just not sure what the best approach would be and I would hope the quality would be good enough.

Any other tips or maybe methods to try would be greatly appreciated. 

Thanks !!