Creating a Spherical Map from a 3D Scene? (Maya)

[Gentle Fury]

Drop a chrome sphere in the center of your scene and render just it reflecting the BG. Then you can either unwrap it in Photoshop or HDR Shop (http://www.debevec.org/HDRShop/) and make it into a spherical image map.......wrap that around a shere and there ya go ;)

[rendermaniac]

A much easier way is to use a normal cube mapped environment map. Just render six views along each axis +X, -X +Y, -Y, +Z, -Z (depending on your software right, left, up, down. forwards, backwards). If your software supports cube based environment maps duirectly (like RenderMan) you just need to get it into that format.

Or paste the images together into a cross in PhotoShop and use HDRshop to change it into a longtitude/lattitude map.

It's also a hell of a lot faster than raytracing a sphere and you don't loose resolution from distortion.

Simon

[Jammage]

Thanks for the help,

Gentle Fury: Cool, that works. To get the full sphere I had to render at least 4 views of the sphere with 90 degree rotations, convert to lang/long, then blend the edges together in photoshop. Is there a faster, more reliable method ..?
I rendered out a 35 frame image sequence of the camera orbiting the sphere (1 frame per 10 degrees) to test if HDR shop could combine them ... however using the "Assemble HDR from image sequence" gave me an image that I had no idea what to do with.

rendermaniac: I tested this out, but I'm a bit confused. I made 6 camera's from one point in my scene, made all the relevant angles and rendered them. I had to adjust the camera Focal Length to get the images to kind of match up on the edges ... however they're still off. The up/down is alot off. Combining them didn't make a complete image I could use ... is there a tutorial or something around that could help me understand how it works better? I'm using maya, but I don't have renderman at my disposal unfortunately.

[rendermaniac]

Try creating an Env Cube texture and plugging your 6 images into it. This then needs to be connected to the reflective colour on your material. (All Maya hypershade stuff).

I don't know if there is an automatic way of getting Maya to render these.

Should have said they all should be rendered with a 90 field of view (or maybe slightly wider).

Simon

[Jammage]

thanks rendermaniac, that works pretty much perfectly. I just needed to keep tweaking the FOV to get the camera edges to match. I ended up connecting the Focal Length of the 6 camera's to an attribute that made it faster to work with.

The Env Cube texture is great also, I never even played with the Env textures before. :) Saves me a bunch of time.

Thanks again!

[Andrew W]

90 degree field of view plus a square film back so 1x1 for example plus (obviously) render square images and that should do it. If your film back isn't square it can cause weirdness in the line-up of the images.

Cheers,

Andrew

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