View Full Version : Circular image mapping

04-06-2012, 01:45 AM
I'd like to make a fancy 'silver' tray with concentric circular embossed or engraved patterns, but I'm wondering what would be an efficient to do the mapping.

Would it be better to brute-force it and just make a square image in Pshop or AI (somehow), or is there a way to finesse it with a linear repeating pattern that gets bent/mapped into concentric circles.

I'm envisioning the pattern itself to be a tesselating Arabic or Celtic type pattern.

Thanks for any tips! :thumbsup:

04-06-2012, 03:42 AM
Have a look in the LightWave 9 content at the Node Surfaces scenes particularly where you'll find Carbon Fiber with a café table-like floor and Compact Disc.


04-06-2012, 05:24 AM
You could make your plate by starting from a Box with a planar UV. Then bend it around to form the round plate. This will leave you with a UV that is square and a plate that is round. :hey:


04-06-2012, 09:07 AM
Thanks guys.

04-06-2012, 09:10 AM
Thanks guys.

The UV approach is probably what I'll go with for this non-paying project, but for a schmancy project I'd want to avoid the widening distortion. methinks I'd either try to compensate with patterns at different 'resolutions', finer towards the edge, or I'd just brute force it in Pshop with a simple linear map.

Which is probably a huge PShop pita, getting it to repeat correctly.

04-06-2012, 09:18 AM
Thanks guys.

The UV approach is probably what I'll go with for this non-paying project, but for a schmancy project I'd want to avoid the widening distortion. methinks I'd either try to compensate with patterns at different 'resolutions', finer towards the edge, or I'd just brute force it in Pshop with a simple linear map.

Which is probably a huge PShop pita, getting it to repeat correctly. :stumped:

04-07-2012, 05:26 PM
You mentioned Illustrator, so here's another idea. Of course, xswampyx's bend idea is great if you want the design in geometry, but if you want to image map it, then Illustrator is your tool. Basically do the same as xswampyx did in Modeler in Illustrator, then use Object:Envelope Distort:Make With Warp ... Circle, Voila!

As a vector (resolution-independent) format, you can either copy to Photoshop, or "Export" to a raster file at a resolution of your choosing.

04-07-2012, 06:30 PM
hmm... theoretically, you could use a bunch of layers of large dots stacked on top of each other.

large black dot for the outer line, slightly smaller white dot as the fill for the outer line, then another smaller black dot then another slightly smaller white dot.

Could possibly put the plate's center at the world center and us a gradient set to distance to pivot to make the rings.

I also wonder if you could play with the one of the ripple textures to do what you want. you'd have to give it one wave source and make the wave speed 0 and tweak a bunch and even then you might not get what you want.

Making the image in photoshop or Illustrator may be the simplest thing. :)

04-08-2012, 07:03 PM
Dana, I'm thinking more of a concentric pattern, not just circles (although, I've always found circles and ESPECIALLY spirals a surprisingly tough trick w/computers in general). (Easier back in the Amiga days!)

Think "vaguely arabic concentric motifs".

The only issue w/UV mapping is I'd prefer the images to not widen out towards the perimeter of the circular tray, but to stay mostly within the same scale. --I'm thinking the straight linear map is the way to go, to preserve my sanity. Althoughhhhhhhhh, since it IS a circle, there's probably a relatively simply mathematical way to calcu how much shorter each pattern needs to be in order to repeat cleanly. It's gonna quantize though, with the width of the 'tile'......)

That is, for a given band on the linear image, you only need to calculate ONCE how much smaller a given pattern needs to be to, ahhhh, "tesselate circularly".

Where's a rocket surgeon when you need one?
Drstrike9, thanks for the AI suggestion: I'm at a very low level in my AI-fu, so keywords like "Warp" are vey helpful.

04-09-2012, 09:55 PM
At first, I thought you were saying that you wanted concentric circles, not just a couple of circles, so I thought I'd demonstrate the techniques I discussed. Of course, after I reread your post, I understood what you're after.

I wonder if you could taper the UV to squeeze the outer rim together to compensate for the spreading apart of the points toward the outer edge. I imagine that would really mess with the tiling, though. Plus it'd distort the texture, so you'd have to compensate for that.

You could possibly use a gradient to drive the number U or V tiles on the 2D image node provided you could find a way to base the gradient on UV space. You could, of course, use a gradient image applied to the same UV map.

04-10-2012, 10:23 AM
To clarify that last sentence: You could apply a black to white gradient (ramp) image via a 2D Image node that has the same settings as the pattern tile image node. Plug the output of the ramp node into the input of a gradient node. The value of the keys on the gradient will control the number of times the pattern will tile. Plug the output of the gradient (color or alpha, whichever you're using... alpha is probably safer because it's unaffected by CS settings) into the U or V tile input on the pattern image's node.

Instead of a white to black gradient image, you could use solid blocks of shades gray that correspond to the pattern rings on your plate.

I haven't tried this out yet, so I don't know if it works in RL.

04-10-2012, 10:34 AM
Intriguing concept! A little above my nodal skill level though.

04-10-2012, 01:39 PM
Hey Jeric -

I hope I'm understanding what you want... I may be way off.
So, take a look at the attachment. If it's what you're after I'll go into more detail.

I'll try to restate the issue:
you are looking to make, what is now a linear repeating pattern(s) into a circular one for use as an image map without a lot of distortion. yes?

I too would go to illustrator. Basically 4 steps....
Use live trace on whatever imagery you want (better if it's black and white) to get it into usable vector art if it isn't already. Isolate the repeating element and make it a pattern brush. Repeat for each element. Apply the brush(s) as the stroke to circles. You can tweak size and such to your hearts content. Finally, align/center circles in a square page. Use auto sizing in LW for a perfect fit.

Honestly, it won't take you more than a few minutes to do it this way (tweaking time is up to you :)).

I used some random arabic patterns i found on google (in jpg form to start)

04-10-2012, 01:54 PM
JoePoe, that's precisely what I meant.

Excellent walk thru! I popped open my old AI CS2 and WALLAGH! Couldn't be easier actually. (Hat tip to DrStrik9 for also suggesting AI, but this method I believe is easier.) In fact, it's even several mouseclicks easier than I expected, since AI Brushes are applied IMMEDIATELY to selected curves.

Thanks to danaburman, xswampyx, and BeeVee for their instructional input as well.

Attached is an image of the geometry the pattern would have been applied to, had I successfully completed the "Steamy" challenge in time.

04-10-2012, 02:13 PM

Nice use of the repeating image as alpha on transparency (or maybe it's a clip map!)!

Yeah, I think in this particular case (and believe me, I'm no expert), the "brute-force" option would be to try and manipulate the artwork in LW itself.

Glad it helped. :D

04-10-2012, 03:36 PM
Well, that edge detail didn't require any AI intervention, since LW itself repeats patterns on cylinder mappings very easily. (And it's a clip map.)

the AI brush mapping is TOO much fun-- my first acceptable thing didn't even really repeat like I wanted. Spent a LOT of time playing w/the built in brushes.

To demo how easy it is to get a circularly repeating pattern in AI, I whipped one up and applied it as a color map. I kept my first attempt as a bump map. Posted here as the second image.