I'm trying to warp an image so that it will appear undistorted when projected onto a horizontal cylinder. The projection is 1:1 -- no magnification -- so the image height is slightly less than the cylinder diameter. In a ray tracing the lines would all be parallel. I've made a couple of attempts at warping it manually, which showed that it could work, but I was wondering if there was a more accurate way to do it. Thanks!
#1
Just trying to project my head around this: are you talking about transforming an original image so that it should look undistorted from a certain viewpoint when actually projected? Or is it the other way round - like a pole with a "projected poster" on it, wrapping around the surface?
#2
You can do this with the Flexify plugin from FlamingPear.
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http://www.flamingpear.com/flexify.html>
#3
Freeagent : I don't want to wrap the image around around the cylinder. I want to "pre-distort" it -- some sort of non-linear warping, greatest at the top and bottom -- so that it will appear undistorted when projected onto the horizontal cylinder.
Phos+for: Thanks for the link -- i'll take a look.
Peter
#4
That's what I was wondering about - would't it depend on the viewpoint? The projector itself would "see" it as OK..?
#5
OK, I think I know what you mean. I'm just having a Bad Brain Day, I'll see you all tomorrow.
Phos' plugin will take care of it.
#6
What is "Phos'plugin", and where is it?
#7
<
http://www.flamingpear.com/flexify.html>
Thanks for the tip! I downloaded the trial and ran it, changing the Input to cylindrical and the Output to equirectangular. The result looks promising.
#8