bagginsbill opened this issue on Apr 29, 2008 · 496 posts
bagginsbill posted Wed, 30 April 2008 at 11:48 AM
So now I'm going to yank your chain a little bit.
Did you guys fix the bug in User_Defined? Perhaps you don't know about the bug?
It does not use the numbers you type in. Never has. It squares them.
If you type in .7, you get .49. If you type in .5, you get .25. The only numbers that work are 0 and 1, because 0 * 0 is 0, and 1 * 1 is 1.
Proof - examine this shader, preview, and render. Gamma is 1.0 here so gamma correction is not causing the problem. I have a UserDefined(.5, .5, .5), and another one that is UserDefined(1,1,1) plugging in Math_Function(.5). They should be the same. They are not. The UserDefined(.5, .5, .5) is producing RGB(63, 63, 63) instead of the RGB(127, 127, 127) that it should.
This has been the case forever. I cannot use numbers typed into UserDefined. I must type them into math nodes and I can plug those into a UserDefined(1,1,1) to get the color I want.
By the way, thanks for patiently explaining all this stuff to me back in November. I love the improvement from the Gamma correction, and I now totally understand and appreciate how the "Input Gamma" is being handled in the nodes, both for input colors and for input images. It requires a bit of careful thinking when doing math, but for basic visual shader design (with the GUI) it works perfectly.
Oh - one more thing. I'm using Final Release Candidate 192B and this may have been fixed since. When I change render gamma to 1.0, that material room Poser Surface preview is dark - i.e. what would be the internal results just before a gamma correction would be applied. But there is no gamma going to be applied. I should never see the internal results anyway, but in the case of Gamma = 1, it should be the same as external results, and it's not.
Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)