I have use both sphere and cross (or cube) mapping for reflections. Both work fine, and have advantages and disadvantages, depending on the specific situation. The fact that an environment is a "cube" is not an issue. It is simply a different way to map the environment. The fact that it is a cube is not apparent in the resulting rendered image. I understand your concern, but it looks just fine. It is just easier to paint out the polar "pinches" in this format. Nicholas is correct in that you can just turn the change the format of the environment map and you loose nothing.
make both a equirectangular and cube format environment map and choose what works best for you. I think you will see there is no difference, except when painting out the pole pinches. On Tue, Jul 30, 2013 at 5:15 PM, Nancy Jacobs <illus...@mip.net> wrote: > Thanks, Stephen and Nicholas for the information on cubical projection. > Frankly, I'm partial to spheres... I've always found them better as > background environments -- cubes never seem right, the edges tend to be > apparent. especially because this is a scene in a 360 space and i don't > want to have to avoid the camera looking at the edges of the cube. But I > also don't want to have to avoid the poles of a sphere. But I've never > tried the cubical projection in Softimage, is it better somehow? You're > right, Nicholas, it would be easier to paint out the distortion in PS. But > I don't want to do all that work on creating a cubical projection and have > it not read well in the render. > > Have you used it effectively when you need 360 degree correctness? > > Thanks! > > On Jul 29, 2013, at 4:39 PM, Stephen Davidson <magic...@bellsouth.net> > wrote: > > Exactly. Then use the cross version (Pano2VR creates a horizontal cross) > setting Softimage's environmental mapping to horizontal cross. > Is this not working for you, now? > > > On Mon, Jul 29, 2013 at 2:54 PM, Nicholas Breslow < > n...@nicholasbreslow.com> wrote: > >> The basic workflow I’ve used for this in the past is to convert the >> equirectangular panorama to a cubical projection. Then you can paint out >> the nadir (poles) on the top/bottom of the cube in PS/other to get rid of >> the distortion. You can use Pano2vr >> http://gardengnomesoftware.com/pano2vr.php for the conversion. After >> convert it back to equirectangular. Very similar to the Polar method >> mentioned before.**** >> >> ** ** >> >> Hope that is what you were going for – just glanced and thought I would >> share this.**** >> >> ** ** >> >> *Nicholas Breslow* >> >> ** ** >> >> ** ** >> >> *From:* softimage-boun...@listproc.autodesk.com [mailto: >> softimage-boun...@listproc.autodesk.com] *On Behalf Of *Nancy Jacobs >> *Sent:* Sunday, July 28, 2013 6:25 PM >> *To:* softimage@listproc.autodesk.com >> *Subject:* Re: Environment sphere issues**** >> >> ** ** >> >> Thanks for this info, Stephen, but I really need the spherical >> environment for a seamless space experience. **** >> >> ** ** >> >> Now that I've got the implicit projection working, it does a better job >> rendering the image at the poles, but still not good enough. Guess ill have >> to drag a sphere into Mari and try painting out the distortion. That >> plugin you linked me to gives some cool vortex effects at the poles, maybe >> ill find a use for that! But I still wonder why it's working for your >> images and not mine. Maybe it's in the type of image and what is happening >> visually near the bottom and top of the image.**** >> >> ** ** >> >> >> On Jul 28, 2013, at 1:19 AM, Stephen Davidson <magic...@bellsouth.net> >> wrote:**** >> >> Here is a nice article on creating cubic environment maps from stitched >> panoramic photos, using Blender.**** >> >> very clever:**** >> >> http://www.aerotwist.com/tutorials/create-your-own-environment-maps/**** >> >> ** ** >> >> On Sat, Jul 27, 2013 at 9:42 PM, Nancy Jacobs <illus...@mip.net> wrote:** >> ** >> >> Stephen, this plugin really didn't work for me. It way overdid some kind >> of smearing, spiraling algorithm. Looks a lot worse than the original. I >> wonder what he's thinking, or what went wrong here... Any ideas?**** >> >> ** ** >> >> Thanks for the link, however. I was really stoked when I thought it was >> going to solve this problem. Maybe something in Softimage mapping is trying >> to solve this and doesn't quite do it, so this plugin overcompensates?*** >> * >> >> ** ** >> >> I still think implicit mapping would help, as the help files indicate, if >> I could get any image to show up on the sphere.**** >> >> ** ** >> >> Thanks again,**** >> >> Nancy**** >> >> >> On Jul 27, 2013, at 8:18 PM, Stephen Davidson <magic...@bellsouth.net> >> wrote:**** >> >> If you have Photoshop, here is a link to something called spherical >> mapping corrector:**** >> >> http://www.richardrosenman.com/software/downloads/**** >> >> ** ** >> >> No 64 bit support, I believe.**** >> >> ** ** >> >> here is the install and use docs:**** >> >> Spherical Mapping Corrector - v1.4, © 2008 Richard Rosenman Advertising >> & Design. Release date: 03/15/03, Updated 09/28/08.**** >> >> ** ** >> >> ** ** >> >> INSTALLATION:**** >> >> ** ** >> >> Simply unzip "spheremap.zip" and copy "spheremap.8bf" to your >> "\Photoshop\Plug-Ins\" folder, or whichever plugin folder your host program >> uses. Load your program, open an image, go to the plugins menu and select >> the plugin.**** >> >> ** ** >> >> ** ** >> >> DESCRIPTION:**** >> >> ** ** >> >> This filter produces texture map correction for spherical mapping.**** >> >> ** ** >> >> When projecting a rectangular texture onto a sphere using traditional >> spherical mapping coordinates, distortion ('pinching') occurs at the poles >> where the texture must come to a point. Given the different topology of a >> plane and a sphere, it is impossible to avoid this, or any kind of >> distortion. However, by properly distorting the texture map, it is possible >> to minimize and even compensate for the polar distortion.**** >> >> ** ** >> >> Special thanks to Paul Bourke for allowing his algorithm to be ported to >> this plugin. For more information, please visit Mr. Bourke's site at >> http://astronomy.swin.edu.au/~pbourke/.**** >> >> ** ** >> >> Sub-Sampling: Specifies what type of pixel sub-sampling to use. (Nearest >> Neighbor being fastest, Bicubic being best.**** >> >> ** ** >> >> On Sat, Jul 27, 2013 at 6:46 PM, Nancy Jacobs <illus...@mip.net> wrote:** >> ** >> >> Greetings, >> >> I'm using the old-style environment spheres with an HDR image wrapped to >> light the scene, but invisible to rendering, and a beauty image visible to >> the render. The problem is the very visible distortion near the poles of >> the sphere. I need 360 degree visual acceptability. I am using a background >> which I've made seamless in both directions, a 2:1 rectangle. It seems this >> worked in renders at one point years ago in another software. Perhaps even >> XSI....I don't recall. >> >> I'm also trying to substitute this arrangement by using both an >> environment (using the HDRI), and 'Spherical Mapping' (using the beauty >> image), in the Pass Shaders. But I'm getting very strange results, so not >> sure if this is the way to go. Also, it's difficult to line them up >> properly so that the light in the HDRI is coming from the same place as the >> equivalent visible areas in the beauty image -- which of course one can do >> easily in the wrapped spheres. But in the pass shaders, they don't seem to >> use the same rotation systems... >> >> Any advice on getting an undistorted, seamless image going here? With >> proper orientations? >> >> Thanks, >> Nancy**** >> >> >> >> **** >> >> ** ** >> >> -- **** >> >> Best Regards, >> * Stephen P. Davidson** ** >> **(954) 552-7956* <%28954%29%20552-7956>* >> * sdavid...@3danimationmagic.com**** >> >> *Any sufficiently advanced technology is indistinguishable from magic**** >> * >> >> >> - Arthur C. Clarke**** >> >> [image: cid:] <http://www.3danimationmagic.com/>**** >> >> >> >> **** >> >> ** ** >> >> -- **** >> >> Best Regards, >> * Stephen P. Davidson** ** >> **(954) 552-7956** >> * sdavid...@3danimationmagic.com**** >> >> *Any sufficiently advanced technology is indistinguishable from magic**** >> * >> >> >> - Arthur C. Clarke**** >> >> [image: >> http://www.3danimationmagic.com/3Danimation_magic_logo_sign.jpg]<http://www.3danimationmagic.com/> >> **** >> >> > > > -- > > Best Regards, > * Stephen P. Davidson** > **(954) 552-7956 > * sdavid...@3danimationmagic.com > > *Any sufficiently advanced technology is indistinguishable from magic* > > > - Arthur C. Clarke > > <http://www.3danimationmagic.com> > > -- Best Regards, * Stephen P. Davidson** **(954) 552-7956 * sdavid...@3danimationmagic.com *Any sufficiently advanced technology is indistinguishable from magic* - Arthur C. Clarke <http://www.3danimationmagic.com>
