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inaccuracy of blend mode (materials / textures)

Posted: Mon Mar 23, 2020 2:04 am
by wob
indigo's inaccuracy of blend mode (materials / textures):
blend errors.jpg
the borders of the plane remain visible, although it must be invisible.

can you fix it in next releases?

thanks.

p.s. i attach zip'ped cinema 4d r20 scene.

Re: inaccuracy of blend mode (materials / textures)

Posted: Mon Mar 23, 2020 4:01 am
by Originalplan®
Hey wob.

I tested your scene. It seems that it is rather your setups fault then Indigo being inaccurate.
Just copied your materials blend noise to a normal c4d material, and you can still see the same edge being there on a normal color channel. Thus it's a normal behavior for c4d also, and has to do with the noise overflowing your object.

Image

Re: inaccuracy of blend mode (materials / textures)

Posted: Mon Mar 23, 2020 4:14 am
by Originalplan®
A good rule of thumb is with noise in general, to handle them as patterns (since they are patterns) aka somewhere on the object & seeds it will repeat like a tile pattern.

Re: inaccuracy of blend mode (materials / textures)

Posted: Mon Mar 23, 2020 7:45 am
by wob
Originalplan® wrote:
Mon Mar 23, 2020 4:01 am
Hey wob.

I tested your scene. It seems that it is rather your setups fault then Indigo being inaccurate.
Just copied your materials blend noise to a normal c4d material, and you can still see the same edge being there on a normal color channel. Thus it's a normal behavior for c4d also, and has to do with the noise overflowing your object.
no, it's not a normal behavior of indigo. because i tested blend mode with png (black & white) images too and got the same thing (black borders instead clean alpha). it's not a cinema 4d problem becase you can see how standart physical render made it (zip`ped scene attached):
Untitled 2.png
but!

i found that this problem of indigo appers only this uvw mode of texture. in cubic mode there is no black borders with noise patterns:
blend errors cubic.png

Re: inaccuracy of blend mode (materials / textures)

Posted: Mon Mar 23, 2020 9:40 am
by Originalplan®
but!
i found that this problem of indigo appers only this uvw mode of texture. in cubic mode there is no black borders with noise patterns:
You didn't had a UV map on your object so it can be UV related ofc.
By me even in cubic mode I get the error c4d is showing me in the view. Even in your physical scene c4d shows me an error in the viewport. That I mentioned earlier.

Image

And after rendering the same error shows up in Indigo.
So Indigo is correct to viewport. Why c4d does not show it in his own physical renderer I don't know.

Re: inaccuracy of blend mode (materials / textures)

Posted: Mon Mar 23, 2020 11:18 pm
by wob
Originalplan® wrote:
Mon Mar 23, 2020 9:40 am

You didn't had a UV map on your object so it can be UV related ofc.
By me even in cubic mode I get the error c4d is showing me in the view. Even in your physical scene c4d shows me an error in the viewport. And after rendering the same error shows up in Indigo.
So Indigo is correct to viewport. Why c4d does not show it in his own physical renderer I don't know.
i attached no viewport screenshots, but final rendering images. you can test it with any png black and white image as alpha blend and you'll get the same result with black borders on the final renderings (in cinema 4d or in indigo standalone). perhaps it's problem with uvw texture tag. i didnt get the same problem with another render engines.

Re: inaccuracy of blend mode (materials / textures)

Posted: Tue Mar 24, 2020 2:02 am
by thesquirell
Hey there wob!

Never encountered a problem like this. But after recreating a scene in couple of scenarios I managed to reproduce it, and solve it by adding a slight padding on the edges of the uv unwrap. It's an usual practice in gaming industry, since it reduces bleeding. But I'm not sure if it will work in all scenarios, especially if you are using c4d's shaders and effects, and baking them.