Bending images in photoshop... or a better way?

Tom Ellis

Hey there,

I'm trying to figure out a way of creating a decent looking circular texture for a tyre sidewall.

I figured it'd be a straightforward thing to do but I can't seem to find a good way of 'bending' any images in Photoshop.

Obviously if I was using text then it'd be simple, but is there a way to have an image 'follow a path' or bend to a specific radius?

Let's say I've got my sidewall UV's, and I want to put a Goodyear or Pirelli or the tyre size/speed rating on the sidewall, how do I bend that image to fit nicely?

I know there's a way to do it by mapping an image to a plane in Max, bending it 360 and rendering it out, but I was hoping for a way to do it solely in PS.

Or would I get better results unwrapping both the sidewall in the same way as the tread and laying them straight rather than planar style from the side?

Thanks

Vrav

I'd do the last thing you mentioned, but I just really like straight UVs. Does get some distortion, but it's so much easier and faster to work with, not to mention saves UV space (in a way, rather than a bunch of circles.).

Sean VanGorder

I agree with Vrav. Taking a little extra time in the unwrapping process to straighten your UVs and organizing them well will save you texturing time in the long run.

James Edwards

Use the pen to make a path or use the shape tool set to 'path' in the tool properties if you want a perfect circle, then use the text tool. Clicking on the path before typing will allow you to conform the text to the path. Cursor should change to let you know whether the text will be on the path or not as you hover over it.

NM I see you are wanting to do it with an existing image then? Do you have CS5? Could try the new puppet warp tool.

nezach

While I agree in general with the setting up your UVs sentiment, check out the "Polar Coordinates" filter under Distort filters for a Photoshop way of doing tire sidewalls. It's no bend modifier, but if you set it to 'rectangle to polar' (I think it defaults to that) and play around it can do similar things.

renderhjs

TexRipper can do that kind of stuff, just the other way around:

thread:
http://boards.polycount.net/showthread.php?t=54694&page=4

For the other way around use the warp tool in photoshop:
edit > transform > warp
it has similar bezier curves to control the rectangle.

MaD

Another easy way to do this:

Make a segmented polystrip in your 3D prog -> bend it -> match it up with your tyre sidewall -> add your texture and render it out in the right view.

Edit: Laurens does this kind of technique in his hotrod tutorial. Day 7, i think the second part. It's for his normals, but that doesn't matter.

Tom Ellis

Thanks for the replies. It seems that straightening the UVs would be the simplest way.

I've just found a tut on CGCars which is similar to the method MaD mentioned. Surely mapping to a strip of polys then bending is effectively the same as straightening UVs since both methods involve the same radial distortion ultimately, just in a different order.

I will give it a shot.

Thanks again.

Xoliul

Just a remark, I don't usually straighten tire sidewall UV's, since you can get some pretty extreme deforming if you do it on thick tires (large distance from outside of tire to rim). Also, another reason is that you want the tread to tile, but not the sidewall. I usually stack something like four 5-segment parts on top of each other, makes for very efficient and easy texturing of the tread. But if you'd straighten the sidewall as well, you have to unwrap that part unique (or everything unique if you want to avoid seams), plus you get this really long strip of poly's to fit into a square sheet, can be tricky if you unwrap the wheels separately.

Vrav

I knew Xoliul was right, but was curious so I ran some radioactive checkerboard tests. Flat style unwrap looks okay if you have more geometry (because it's less of an angle between the faces in the strip, etc). I still might use it myself for the potentially easier texture process, but eh, planar/circular unwraps don't look too tough to detail, after all the other tips in this thread.

00Zero

maybe you can paint the texture straight, then apply it to a long poly strip and then use bend modifier or something similar and get it into a circle, and weld it onto your tire

Vrav

Yeah, or texture the flattened one and bake to the circular UVs using RTT, clean up.