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re: creating spherical texture maps
I’m trying to create in photoshop a texture map for a sphere. I know the image needs to have a 2:1 ratio but need a way of creating the required amount of distortion to compensate for the spherical texture mapping.
I thought this would be a common problem with many possible solutions, but so far have drawn a blank.
Should I be exporting the mesh from C4d first? Again, how do I do this?
Many thanks
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2 Replies
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Hi Nicol,
There is one thing first off to note- Cylindrical mapping will most likely give you a better result with less overall distortion and more predictable results that spherical…i couldn’t tell you why, but i have noticed it from experience:
This is a problem which can be fairly easily solved if you have a copy of photoshop handy there is a very useful build in plug-in:
Filter > Distort > Polar coordinates
This has a pop-up which asks if you want Rectangular to Polar or vice versa, choose rectangular to polar.
what you have now is a view of your texture ‘sort of a’ looking straight down from the top- You can now paint out the pinching distortion as you see fit.
when you have painted out the distortion use:
Filter > Distort > Polar coordinates
again only this time choose Polar to Rectangular.
This returns you back to your original image only now you will have what looks like a crazy stretch at the top, this is the texture you have painted stretched out to fit into it’s new texture space.
At this point It’s probably best to save under a new name and re-import it into cinema and render it from an advantageous angle: so you can see how well it works.
After you have seen how amazingly well this sorts your problem 🙂 you have to realise this is only the top that you have fixed:
So back in photoshop again you will have to rotate your entire image 180 degrees and perform the same operations again on the bottom half of your texture…ta da!
like you say this is a very common problem and you will find yourself doing this operation fairly often if you are
Hope this helps, if i wasn’t very clear at any of these points, just ask a question and i’ll see if i can clear it up.
all the best,
Martin.
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Hi Martin,
Thanks very much for your help.
I had come across this technique as a possible solution however it didn’t seem to be appropriate in my case as my texture is a graphic repeated pattern. Any inaccuracy in the distortion would be easily spotted on my sphere!
This time I modelled my way around the problem but I can see myself using the polar co-ordinates technique alot in future!
Thanks for the tip regarding cylindrical mapping and thanks again for taking the time to respond to my post.
Kind regards,
Nicol
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