This will not work. When you look at a sphere, it reflects about 90% of the 360 degree universe around it.

Your photo is only about 10% of the universe, maybe less.

For the perspective to work out correctly, imagine a photo suspended behind the camera of what the ball can see, like a billboard. You put your photo of the road in that direction on the billboard.

Now imagine rendering the sphere. You will see a reflection of a billboard with your photo on it, along with all the rest of the sky and ground. You will not see the billboard fill the sphere.

The only way this can work is if you have a full 360 by 180 degree equirectangular image, as you would use on my Environment Sphere. That is what should be in your sphere_map.

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)