Welcome, Guest. Please Login or Register
Home Help Search Login Register
Page Index Toggle Pages: 1
Send Topic Print
panoramic transformations for 3D rendering (Read 4373 times)
shadows44
Ex Member


panoramic transformations for 3D rendering
12/16/08 at 11:33:47
 
Hi everyone,

I've been playing with HDRI panoramas for a while ; the main goal is to use them for 3D rendering.

The issue is, 3D renderers have specific "needs", and some of them want latitude/longitude (equirectangular), while others only want cubemaps or angular maps.

HDRShop can of course convert panoramas, but v1 is for non-commercial use, while v2 is, well, quite expensive (400$) and old (several years without any update, I guess).

I've tried to find panoramic transformation features in various HDR software, but most of them don't have such feature...
Qtpfsgui supports equirectangular and angular, but not cubemap.

Any idea of which software could help me ?
Back to top
 
 
IP Logged
 
Blochi
Administrator
*****
Offline



Posts: 1726
Hollywood
Re: panoramic transformations for 3D rendering
Reply #1 - 12/16/08 at 15:28:47
 
Your best options are:

- Flexify, a Photoshop plugin that converts everything to everything very conveniently. Needs CS3-4 Extended, though...

- Hugin, a free HDR-capable Stitcher. Even though you don't really stitch, it can take Equirectangular Images and render out anything else...

Actually, any of the 4 stitching programs on the software list will work.

Blochi

Back to top
 
WWW  
IP Logged
 
shadows44
Ex Member


Re: panoramic transformations for 3D rendering
Reply #2 - 12/16/08 at 20:46:30
 
Quote:
Needs CS3-4 Extended, though...
Ouch... Elements would have been ok, but extended is way too expensive ! Sad
I will try it with elements anyway, just to be sure...

I tried to convert hdr pictures using Hugin a few days ago, and even if many panorama projections are provided (especially for a beautiful "planet effect"), there does not seem to be any cubemap or angular map support.

I also own Autopano Pro, which is really great but like Hugin, no cubemap or angular map, just equirectangular.
Back to top
 
 
IP Logged
 
Blochi
Administrator
*****
Offline



Posts: 1726
Hollywood
Re: panoramic transformations for 3D rendering
Reply #3 - 12/16/08 at 22:10:12
 
nope, Elements does not support 32 bit.
Actually, I'm not all sure if you really need Extended for Flexify to work. CS2, 3,4 all have basic 32bit capabilities built in.... but to really get some additional cleanup work done, you get Layers and image adjustments in Extended....

In Hugin, try Equirectangular as Input and Fisheye as Output. Set hFOV to 360 on both, and set a square output size. Just tried it, gets you a perfect Angular map. Cubemap you would probably have to assemble yourself out of 6 render passes, Rectilinear 90 deg hFOV in each direction....

Blochi






Back to top
 
WWW  
IP Logged
 
shadows44
Ex Member


Re: panoramic transformations for 3D rendering
Reply #4 - 12/16/08 at 22:28:55
 
Quote:
nope, Elements does not support 32 bit.

Sure, but another workflow would have been to convert LDR pictures from equirectangular to angular & cubemap, then to use them to create HDR pictures...

On the other hand this would have a huge drawback : not being able to work on hdr files mean that you can't do much posprocessing on your pictures. If you want to correct the nadir, for example, you might get very weird results if the three LDR pictures are corrected separately.

Quote:
In Hugin, try Equirectangular as Input and Fisheye as Output. Set hFOV to 360 on both, and set a square output size. Just tried it, gets you a perfect Angular map. Cubemap you would probably have to assemble yourself out of 6 render passes, Rectilinear 90 deg hFOV in each direction....

I never thought of the fisheye trick, thanks !
The rectilinear rendering workflow will work, even if it's not a very short path...

I guess I will have to work like this until Autopano or Hugin have more features.  Wink

Thanks a lot for your help !
Back to top
 
 
IP Logged
 
sucka
Ex Member


Re: panoramic transformations for 3D rendering
Reply #5 - 12/16/08 at 23:33:32
 
Just curious, and please correct me if I'm wrong.  I've been regularly using the built in re-projection tool within sibl. Although I am going straight from light probe(mirror ball) to Lat/Long almost every time, it's very stable and works like a charm. Is there any reason not to use the tool within SIBL, Blochi?

Thanks!
Back to top
 
 
IP Logged
 
Blochi
Administrator
*****
Offline



Posts: 1726
Hollywood
Re: panoramic transformations for 3D rendering
Reply #6 - 12/17/08 at 00:01:22
 
nope, there's nothing wrong with it.
Chris made this tool because it's such a cumbersome multi-program workflow without it. As you have already figured out. In fact, I highly recommend using the sIBL-Edit's Blur for blurring equirectangular panoramas, because this is the only Blur I know of that works correctly in this image space. Blur in Photoshop or anywhere else does not wrap around the left/right border and does not compensate for Nadir and Zenith. sIBL-Edit's Blur does. It's almost as good as HDRShop's Diffuse Convolution, but about 10000 times faster.

Blochi
Back to top
 
WWW  
IP Logged
 
sucka
Ex Member


Re: panoramic transformations for 3D rendering
Reply #7 - 12/17/08 at 01:09:39
 
Cool. And yes, as you said, it definitely is a cumbersome multi-program workflow without SIBL. SIBL has definitely made an HDRI workflow about a thousand times easier than what it used to be for me.


All hail chris, all hail the SIBL.

Smiley
Back to top
 
 
IP Logged
 
shadows44
Ex Member


Re: panoramic transformations for 3D rendering
Reply #8 - 12/17/08 at 09:03:35
 
Quote:
Blur in Photoshop or anywhere else does not wrap around the left/right border and does not compensate for Nadir and Zenith.
Actuallly it should be able to do that, now. In CS4 you can project a panorama on a sphere, and then do whatever you want to do (nadir correction and so on).
I downloaded the demo yesterday, it seems to be quite easy to use. The drawback : you need 1400$, since this feature is only is CS4 extended. A good graphic card is also needed.

Quote:
Is there any reason not to use the tool within SIBL, Blochi?

I just downloaded sIBL Edit and it seems that it might be the tool I'm looking for !
The app crashes when I try to reproject a big hdr panorama (5000x2500), whereas everything is ok with smaller panoramas (alf size).

I guess this might be due to the lack of RAM on this computer - only 2 Gb ; I will try on another one which has more RAM this evening.
I also didn't manage to reproject and have a good ratio at the same time ( the cubemap had the height/width ratio of the original equirectangular panorama and was therefore distorted )... But I guess I'm just not used to the software yet.  Wink

I will also try to find if there are oversampling options.
Back to top
 
 
IP Logged
 
brad
Ex Member


Re: panoramic transformations for 3D rendering
Reply #9 - 03/23/13 at 13:03:38
 
Quote:
"In Hugin, try Equirectangular as Input and Fisheye as Output. Set hFOV to 360 on both, and set a square output size. Just tried it, gets you a perfect Angular map. Cubemap you would probably have to assemble yourself out of 6 render passes, Rectilinear 90 deg hFOV in each direction.... "


How do I set equirectangular as input ?  If I have a 360 deg set of images, they will be rectilinear.

Can you please give some more detail on how I get from images to an angular map ?

Thanks for any help.
Back to top
 
 
IP Logged
 
Page Index Toggle Pages: 1
Send Topic Print