[Bug] 1x1px textures

manitwo · Post by **manitwo** » Tue Sep 12, 2006 9:52 am

In this Thread i had the idea to use 1x1px Images as textures for the materials because
normal colors have no reverse gamma correction at the moment.

After writing this i tried that:
1. Normal Colors
2. 1x1px images (PNG format)
3. 1x1px images (JPG format)

I think 2 and 3 look good but not as expected

dont know if i am doing something wrong

if someone want to recreate this:
http://rapidshare.de/files/32783560/kegel2.zip.html[/url]

manitwo · Post by **manitwo** » Tue Sep 12, 2006 11:08 am

i tried to enlarge these textures to the size of 10x10 ... and it works - really fresh and well saturated colors.
BUT WHY? why this doesn't work with 1x1 pictures? I think thats a bug

If yes, thats my second discovered bug

now you can call me a real bughunter

Back to topic, what do you say nick?

afecelis · Post by **afecelis** » Tue Sep 12, 2006 11:28 am

great! thanks for taking my question into account and taking the time to create these tests. They're very useful. Totally appreciate it.

manitwo · Post by **manitwo** » Tue Sep 12, 2006 11:41 am

no problem afecelis

from me BIG THANKS to Nicholas Chapman for his renderer and all active forum members !!!!

scorpius · Post by **scorpius** » Wed Sep 13, 2006 4:16 am

Using a 1x1 JPEG is not very reliable because jpg uses lossy compression -- so some of the colors might not be exactly the same as the original. However, they should be almost the same and not entirely different. As far as PNG is concerned, there is no loss -- so that could be a bug.

I simply skipped using the texture trick and manually applied the reverse gamma to the exr output:
http://www.indigorenderer.com/forum/viewtopic.php?t=224

But this gamma stuff should get fixed in a later release. I also noted that the sunflow render developed the same problem right after reverse gamma was added as a feature.