Mirror Balls?

[rcallicotte]

Oshyan, I found this quote from you in a TG support forum on the Internet - "HDR images are not inherently spherical or in any other projection. HDR is really just a definition of the dynamic range in the image. In that sense Terragen already saves out full HDR images in OpenEXR format by selecting that format from the drop-down list in the Save dialog. We do hope to add direct support for rendering cubic, spherical, and other HDR environment map formats."

How close are we to spherical maps?

[ndeewolfwood]

You want to do HDRI environnement with spherical mapping for 3d lighting right ?

If yes
Check this :
http://www.planetside.co.uk/forums/index.php?topic=11608.0
http://www.planetside.co.uk/forums/index.php?topic=14026.0
and this http://www.ptgui.com/ or any software who can do the same thing.

Right now this is a very good way to do until direct support of spherical rendering.

[rcallicotte]

My end result needs to be a spherical image, once I'm done.  This is skybox and panoramas...or am I missing something?

[ndeewolfwood]

you have to render 6 "flat" exr with tgd with a large FOV.
PtGui can stich those renders into a single hdr with a spherical mapping.

PtGui is not the only software how can do this.But is not free.

Check on google keyword like : " cross to spherical mapping, cubic to spherical, stich picture to spherical HDR, etc....)...maybe someone made a freeware recently.

Are you sure you need spherical mapping, in a lot of case cubic mapping are very good for HDRI lighting and reflexion.

[rcallicotte]

Thanks for explaining, ndee.

Yep, I need spherical.  It's for Image World in Lightwave.

[ndeewolfwood]

i don't use lightwave but i'm pretty sure you can do the same thing using your own geometry as a "image world".

Try to create a cube, reverse your normal, add a constant shader to it with your environnement, disable shadow casting and double sided in your object rendering property, and turn on Final Gather.

I do it this way in maya or houdini when i'm too lasy for creating a spherical map.

[Oshyan]

I can't give any specific date for spherical rendering or other direct panorama format output, but we do intend to support it in the future.

- Oshyan

[rcallicotte]

Okay.     This alone could be a big seller in the world of graphics and is good to know.

I can't give any specific date for spherical rendering or other direct panorama format output, but we do intend to support it in the future.

- Oshyan

[King Mango]

I'm okay with rendering a chrome ball as opposed to the other methods since I just use hemispherical skydomes now anyway. Was just messing around a little bit with it tonight and the only way I could find to get a refelction was with the water shader. This works mostly well, but as the angle of incidence increases, the reflection seems to wash out a bit. I haven't been able to finger the right setting.

Would someone know how to get a true mirror reflection this way or is there another solution for reflections?

[AP]

Use this file. It should be as close to a mirror as it should be.

[rcallicotte]

Thanks Chris!  This will come in handy, for sure, and is a cool idea.  This is one way I might affect lighting in another 3D program.

I think what I really want, besides another cool way to light a scene, would be an image like what ndee was talking about.  The way to create such a scene means when I load it into a plugin like Image World in Lightwave, I will have good lighting and I'll have the scene for a background (and the sharper the better).

[AP]

No worries. I figured adding more reflection was to increase the Index of Refraction until the reflective surface was comparable to that of a mirror or a chrome.

[Mr_Lamppost]

Doh!  I hadn't thought of rendering a mirrored ball even though I have seen tutorials showing how to set up and take photo's of them in the real world.  Ultimately i want long-lat projections but a single mirror nall projection has got to be easier to handle that six face images of a cube projection. 

[AP]

The only other advise i may offer is to render each side the the mirror object with two cameras and stitch it together with some software. You have two 180 degree sides that can complete a full 360 degree lat/long map.

[shadowphile]

Mirror-ball approach:

Pros: One render, full spherical coverage, directly usable result so no required transformations or stitching (ugh)

Cons: Unless your skybox is for lighting only, you probably want lots of resolution.  With only one image for every direction, you need LOTS of resolution.
Also introduces distortion at the edges of the image.   This will cause a funky spot somewhere depending on the orientation.  The funky spot can be maneuvered somewhere unimportant like straight up or down.

Cube-faces approach:

Pros: Spread over 6 faces so getting high resolution is easy for skyboxes.
Because the cube-faces are distributed equally around, this approach vs equilateral, angmap, etc introduces lowest distortion anywhere in the image while not requiring massive oversampling like equilateral images do at the top and bottom.  (the entire top and bottom edge of an equi. image represents only ONE point.  High quality yes but at a size cost)
-Any program can generate a cube face set because they are just normal renders.

Cons: Usually requires conversion into something usable by other programs, although some viewers and game engines can use cube-face sets directly.
Requires 6 separate images with different camera angles for each, so clunkier rendering process.

This is from experience, please correct me if I'm wrong.

Also, after years of struggling with HDRShop limitations and lack of alternatives, I came across Pano2VR utility.  It's not free but not expensive either, and it seems to handle huge images with ease (64-bit version).  It will transform just about any panorama to any other, and handles EXRs and HDRs too.  In addition to using it for transformations and alternate image-format outputs, it can also generate HTML5, Flash, and QTVR representations for instant viewing!
It's also set up to easily allow as many different outputs as you desire in one 'go' click.
Cons:
-It has a certain bias against .bmp files, but it WILL read them.  In Windows you have to enter *.bmp in the selection folder for your source images to appear.
-Undocumented how to get it to input a cube-face set in one go, otherwise you have to manually tie each image to a direction, uck.  The format required for auto-loading is to end each cube-face image with a 0 thru 5 digit indicating N,E,S,W,U,D.
-There is also no forum   If it's not in the documentation (which is ok), you are on your own.