tag:blogger.com,1999:blog-8959356083618071167.post5894791783308329502..comments2024-02-24T04:33:15.835-08:00Comments on Beautiful Pixels: Gamma Correct Lighting, On The Moon!Vincent Scheibhttp://www.blogger.com/profile/14142807255428586912noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-8959356083618071167.post-10048542579395098282010-03-01T03:32:12.010-08:002010-03-01T03:32:12.010-08:00Excellent entry! I'm been looking for topics a...Excellent entry! I'm been looking for topics as interesting as this. Looking forward to your next post.Term Papershttp://www.flashpapers.comnoreply@blogger.comtag:blogger.com,1999:blog-8959356083618071167.post-33154278002422180172009-10-15T14:00:39.394-07:002009-10-15T14:00:39.394-07:00It's a nice example.
I also think there is s...It's a nice example. <br /><br />I also think there is something worth considering in Anonymous' comments that the one on the left is more "appealing". <br /><br />Without any reference to correctness, the left does have a more noticable gradient. I could argue that this pronounced gradient helps define the shape of the sphere more clearly. It's 'more obviously' a sphere. I'd suggest it also looks less like the moon, but cheating to help the perception of shape is not necessarily a bad thing.Sam Martinhttp://palgorithm.co.uknoreply@blogger.comtag:blogger.com,1999:blog-8959356083618071167.post-24698465047664165072009-10-15T06:59:05.521-07:002009-10-15T06:59:05.521-07:00Very cool, I didn't really understand the issu...Very cool, I didn't really understand the issue with gamma adjustment before. Thanks for linking to the article, and I think your moon example makes a lot of sense.PsySalhttps://www.blogger.com/profile/03334292849719348870noreply@blogger.comtag:blogger.com,1999:blog-8959356083618071167.post-39113461766505414162009-10-15T01:42:50.041-07:002009-10-15T01:42:50.041-07:00I don't think that your moon analogy is very s...I don't think that your moon analogy is very strange or wrong. Actually, when I first experimented with gamma correction, my first thought was (when viewing a gray sphere): "hey, that looks like the moon now!".roelnoreply@blogger.comtag:blogger.com,1999:blog-8959356083618071167.post-14324876375744378392009-10-15T00:00:48.275-07:002009-10-15T00:00:48.275-07:00The image on the right may be more correct, but th...The image on the right may be more correct, but the image on the left is more appealing.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8959356083618071167.post-58630677155797680142009-10-14T18:28:03.889-07:002009-10-14T18:28:03.889-07:00In the third edition of "Real-Time Rendering&...In the third edition of "Real-Time Rendering", we used an image that communicates this quite well, I think. You can also see it on an old blog post of mine, about a quarter of the way down: http://renderwonk.com/blog/index.php/archive/adventures-with-gamma-correct-rendering/Renderwonkhttps://www.blogger.com/profile/18344985756033636679noreply@blogger.comtag:blogger.com,1999:blog-8959356083618071167.post-6142684909758876952009-10-14T18:00:04.287-07:002009-10-14T18:00:04.287-07:00I agree with the image on the right is the gamma c...I agree with the image on the right is the gamma correct rendering. Though, I disagree with your experiment.<br /><br />The moon has large facets (mountains) that reflects light back towards the person standing on the ground. The lambert BRDF you chose to render isn't representative of the moon.<br /><br />Look at Oren-Nayar for a BRDF that represents the moon better. (In fact the first commercial use of Oren-Nayar was a TV spot that had a moon in the background).<br /><br />-= DaveAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-8959356083618071167.post-54357664575698788602009-10-14T17:52:52.020-07:002009-10-14T17:52:52.020-07:00The moon exhibits quite a bit of backscattering, s...The moon exhibits quite a bit of backscattering, such that the area near the terminator is brighter than a normal Lambertian surface. Is the lighting model closer to standard in that photo, now that the light source (sun) is perpendicular to the view direction?<br /><br />http://books.google.com/books?id=4PxR6Nq4jqIC&pg=PA54&lpg=PA54&dq=moon+%22non-lambertian%22&source=bl&ots=UIcxUzTgEm&sig=U78FNPem-C4GE51sM40d5Z21uw0&hl=en&ei=10d2Spy9C4K0Nr-2_LAM&sa=X&oi=book_result&ct=result&resnum=1#v=onepage&q=moon%20%22non-lambertian%22&f=falseCatnoreply@blogger.comtag:blogger.com,1999:blog-8959356083618071167.post-65442959010315011012009-10-14T16:28:32.486-07:002009-10-14T16:28:32.486-07:00Isn't the moon often used also as an example o...Isn't the moon often used also as an example of how Oren-Nayar can produce better results than the plain old Lambertian model? I assume the above images are using Lambert, is that right?<br /><br />Either way, it's clear that the one on the right is more correct than the one on the left. It's amazing how many games I see that appear to have gotten this wrong.Roryhttps://www.blogger.com/profile/09589126437605795958noreply@blogger.com