Env Sphere vs Env Ball?

[rBrady]

The descriptions are a bit cryptic. Think of the environment sphere is a latitude longitude map like many world political maps you saw in grade school. A ball is as viewed from the reflection of a ball. Both can be full 360 degree images. And if implemented properly you couldn't tell the difference. A simple photo of a ball gives almost a 360 degree. The areas behind the ball don't have much resolution and there is a blind spot behind the ball. Most people shoot the ball from two angles to get a full 360 and remove the camera from the shot.

Here is an example from Paul Debvics site. I took his rather nice ball image and converted it to a lat/long (or sphere) map in HDR shop.




This is the original image. You would use this in a ball environment in Maya.


http://rbrady.com/tmp/Forum/Textures/uffizi_probe.jpg



This is the converted lat/long map. You would use this with the environment sphere node in maya.

http://rbrady.com/tmp/Forum/Textures/uffizi_probeLatLong.jpg

I hope that helps. Let me know if any part of that is unclear.

Ryan Brady

[EricLyman]

Wow, very nice exlpaination Ryan, thank you! I don't think I could have ever figured that one out based on the maya help function.

I had another question about EnvBall as well however, maybe you know? When mapping a file in to the Env Ball node, does maya automatically ignore the corners of the map, or in the case of your example, the black area? My guess is yes as something like that would probably yield unrealistic chrome.

[rBrady]

Thanks and no problem. don't worry about the black areas. They are not used. If you used both of those maps with the correct node you shouldn't be able to tell the difference. Both work perfectly. Assuming that you don't move the chrome object moving significantly in the scene of course. If you wanted to drive a shiny car through a parking garage you would need the reflections to move. Thats where the "Environment Cube" node comes into play. They are more work since it takes 6 images, but they animate properly.


Ryan Brady

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