GLSL Node Materials Broken ?

Hello, i did not find any clues on the internet about that, but it seems that the Material nodes are broken since some past Blender versions ( and the newest one). I wanted to blend two materials with an alpha texture. This works with 2.69 but it doesn´t work with the latest one. Why is that ?

Greetings Mathes

Someone know why it does not work ?

I would guess that the result you are piping into the factor is always 0 or 1. Try unplugging the factor and manually changing the factor. Does that mix work?

I’m not really an ace in math (far from it), but to me the result for the Fac input seems to always be 0 or negative:

Fac = [tex color value] - [clamp (( tex color value modulo RGB color ) x 20000 ))]
The left square bracket is between 0 and 1 (unless that’s an HDRI) and the right square bracket will always be 1 because of the large multiplier. No?

Well its not the problem with the math or method , it would not work with any other node material - someone asked me to set up a bug report, but i had too much to do the last days. It seems like the GLSL and the Node Material System is broken. It worked with blender-2.67b-windows64. I will post the bug report today. Thanks for your answers

Sorry, but I don’t get your problem… Blender 2.71 x64 “official” / Win 7 x64, GLSL, two node materials, alpha texture as mix factor - works as expected:

The problem is your math. Your example material mix starts to work as soon as you lower that multiplier from 20000 to something more reasonable… Maybe you should check that again before filing a bug report.

Maybe you should check that again before filing a bug report.

What is wrong with the Opensource community these days. First, i asked anyone on multiple Forums and chat about this. I got only one answer that was very precise and reasonable. So as i am not a newbie i first try everything out if i might find something that looks like a bug or something.The last thing you want to do, this is a base rule of thumb on the internet, is to bore, to offend or to ask stupid questions you can resolve with one google search. So, yeah, all that checked before. Thanks for let me feel like a newb. The way it used to be on the commercial programms now available in blender for free.

Oh and i did not wrote a report yet, because i first looked here if there might be a message that resolves the problem.
If someone might think this is a bit overreacted, its just the impression that expanded in the last years. I remember joining a blender community nearly 10 years ago. It was a whole other experience. But hey enough of this.

So ok, so my math was wrong and yes your way works. This happened to me, because i usually don´t work in Blender that much. My work is more on the exported gameengine side and less in the modeling programs. Blender has allot of different material nodes compared to the other engines (and they are far less than the current game engines have) My thought was to subtract a key color, than use the subtracted rgb value to determine the correct alpha of one color ID. The problem was that the black and white value was not clamped good enough, so i wanted to use a very high value to multiply it so that it is clearly white. This was very imperfect, but on the Other hand, i was surprised it worked on the older blender versions. So i was confused and after searching for hours i found no exact topic on that, although i knew someone had to done this similar before.
So i did not know what to do, and this questions are the hardest.

In short, this is my new approach. I am interested in any similar way to this if someone knows more threads or simliar threads to this. For the next update on this, i will read deeper in other examples on the internet to optimize it.

If i get this to work, its not a big tool or perhaps not that big of useful, but i hope to make some interesting approach to visualize a Material ID method so it is easier to export them in PBR Gameengines.

Thanks for your response, and for now this is resolved.
Many greetings,

Edit: Oh and while this does not explain why other methods did not work either, i assume this was just a problem because i do not know the limitations of the Material Nodes and GLSL.


So, basically two people in this thread told you that you should investigate the math feeding into you mix factor. Instead of doing so, you just waved that aside and denied that either your math or your input could have anything to do with it and that you now would file in a bug report.

Knowing very well how much work compiling a thorough bug report can make, I prepared a working example for your undertaking to give you another incentive for investigating and checking your setup - and be it only to prevent the developers from having to see through an overhasty bug report.

And as a thank you I get a lecture about the decline of open source communities and that I should feel bad for making you feel like a newbie? Dude, whatever, but welcome on my ignore list.

So jeah just use your point to stand against that, but what is missing that i tested a simple alpha texture with a mix that did not work and this has to work. So thanks again. Just getting better. And oh, and someone of the blender builder stated that it CAN happen that the materials nodes have bugs since there is a development around that.

Darn it, just another example of the fact that the internet is so egalitarian that you never know when you are dealing with a Very Important Person!

Darn it, just another example of the fact that the internet is so egalitarian that you never know when you are dealing with a Very Important Person!

Which is the most unessesary thing to me, if this would be a compliment because i would not care (but thanks then anyway). And if its Sarcasm, the last sentence also shows that this is nothing i would be interested in. But as i said, i somehow feel like the Community change. It grows so big, that it can be hard to have a problem you do not know what to do with it. And if its technical, you might end up feeling struggling if you really want ask the question. Thats what changed for me. And to say this, Blender and the Blender Community helped me to be what i am now and the job that i have. So i have a huge positive impression of what i felt to be a part of the open source community.

But thats offtopic, whats ontopic is that i kind of manage to reproduce the bug. But it seems that its my own Computer having this problem, a graphics card problem. And at this point, it will be difficult to reproduce or to fix it or even find the problem. Also, this is solved then anyway, because the problem is found “somehow”. So i guess no bug report necessary after all the testing around. So saving money for new computer…