Out Transparency - I admit, I JUST don´t get it


#1

I connect the simpliest black/white texture to a surface Shader´s Out Transparency. I assign it to an object. My Thumbnail in Hypershade looks just like what I want - I even get a nice transparency in the Viewport. But there´s no transparency in the rendered object. With a blinn or lambert, that works just fine.

What´s the difference between “Out Transparency” and “Transparency”? Also I realise that if I attempt to make a connection via Hypershade, in case of the surface shader Hypershade only offers a displacement connection. When I drop it on a blinn shader, I get a huge list of possible connections.


#2

If you leave the surface-shader color black, it will render with the transparancy you expect.

The surface shader out-color works like the blinn/lambert incandescence, in that it adds color value after transparancy, so surface-shader’s out-color=white or blinn’s incandescence=white totally over-rides transparancy.

If you want your transparancy to work AFTER all other shader calculations, then you need to use a layered-shader (even though you may only want a single layer). Set its mode to “layered texture” or else specularaity will still be added after transparancy. When you drag a shader into the layered shader both color and transparancy are connected automatically, but this isnt what you want. You need to drag your transparancy texture and drop it on the transparancy input of the layered shader (ie you dont need to connect this transparancy texture to your surface shader or blinn, it connects directly to the layered-shader)

Sound complicated doesnt it? In practice its easy to set up, but I cant help wondering why they didnt just put a little switch in the materials attribiutes that lets you decide when transparancy is factored into the calculation.


#3

Hei djx :thumbsup:

Many thanx for explanations…

Where do u get all that usefull info about the way shadingNode’s attributes affect each other?
I understand the general way they way it works but i d like to know the way MAYA interprets them…:wink:
Is the method of learning this concepts based on just subjective experiments…Do you have any usefull links and resourses about it?

Thanx…


#4

ah? Cool!

Thanks a lot! That puts quite some logic behind the results I got in my tests - the weirdest one was where I had a black/white picture I used as color and alpha, and I managed to get one color transparent, but not the other… :shrug:

I wonder why all that´s tfm says is that “it´s the transparency and by default black” … :banghead:
They probably try to bring out the scientist in all of us :slight_smile:


#5

leha_sokol: Some of that explaination I got from the manual, but not directly. Usually the manual is where I go when something isnt working - sometimes it helps, sometimes not - and then I keep experimenting to try and find some logic. In fact this forum is where I pick up much needed information.


#6

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