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I'm trying to experiment with an animation project that requires the use of a spherical background image. The image I wish to use comes from a program that outputs six images; one for the top, bottom, left, right, front, and rear views.

Originally, I tried getting these stitched using an external program to create the spherical projection that can be used for a background in Blender. This worked perfectly, as far as seeing the image was concerned. However, the only free tool I could find places a watermark on the image.

So before I ask if a fully functioning free tool exists, is there a feature or add-on in Cycles that can create the intended background using the available images?

If it matters, the node setup I used for the watermarked image was: enter image description here

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  • $\begingroup$ Related - blender.stackexchange.com/questions/32493/… $\endgroup$ – Mr Zak May 15 '17 at 21:21
  • $\begingroup$ Hmm, so it looks like a Blender solution is out of the question. And I assume no change over the two years since that post? Guess that leaves a third party tool. Question is, which one? $\endgroup$ – Hiigaran May 15 '17 at 21:30
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    $\begingroup$ You have option 2, you can create a cube around your scene and unwrap it to your skybox, not many downsides to that $\endgroup$ – Duarte Farrajota Ramos May 15 '17 at 21:36
  • $\begingroup$ How will that work with lighting? Sun lamps, for instance? Would the image even be visible unless the cube had an emission node on it? $\endgroup$ – Hiigaran May 15 '17 at 21:40
  • $\begingroup$ There's also backwards process - blender.stackexchange.com/questions/28328/…, maybe it could be useful. As to the tool I think panorama stitchers should be able to do that, Hugin is free one. Btw which tool did you use to get with watermark? $\endgroup$ – Mr Zak May 15 '17 at 22:03
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One approach you could use is to create a special converter scene using cycles.

Place the camera in the center of a cube and give each face of the cube its own material based on one of the face images (honestly: rigging the materials and the UV coordinates will probably be the most time-consuming part of this exercise). You probably want to use an emission BSDF.

Then change your Camera > Lens from Perspective to Panoramic. Change the new Type: to Equirectangular (unless you want one of the others). Then render one frame and you should have an equirecangular version of the scene.

Save that image and you should be able to use it as the environment in your main project.

There is also https://github.com/Samsung/360tools, but I have not investigated the exact command-line for converting from a cubemap to equirectangular, and it might require you to convert to YUV and back.

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  • $\begingroup$ blender.stackexchange.com/a/13435/660 has screenshots of the UI for setting the panoramic camera. $\endgroup$ – Mutant Bob May 16 '17 at 20:29
  • $\begingroup$ I'll try getting the stitching to work, but if I can't do it (and it looks like that might be the case), I'll give this method a try. I assume that the camera settings will eliminate the problem with seeing the edges and corners of the cube, and give it a proper spherical look? $\endgroup$ – Hiigaran May 17 '17 at 0:28
  • $\begingroup$ As long as the images are generated with the proper perspective and aspect and no overlap for a perfect cubemap, it will be fine. If the cubemap rendering process did generate some margin, you'll have to read the documentation of the generator and do some math to figure out the adjusted UV coordinates. $\endgroup$ – Mutant Bob May 17 '17 at 14:05

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