[BUG ]Blend color bug!

[zeitmeister]

Hi,

something seems wrong with blend modes based on textures.
When using an 98% white, Indigo darkens tremenedeously.
No matter what rendering mode, or glass acceleration enabled or not, or which light layer type, or which texture gamma, or if double-sided mesh or not.

On the right you see a 98% white texture between the 0% white grid.

Would you please check this issue? 98% white doesn't have to darken that much what is lying beneath.
C4D scene and Indigo scene attached.


Thank you in advance!

[Zom-B]

well... the problem here is that you use Sun as alight source!
You see the fireflies at the right cube?!
That is the brightness you are waiting for

Render with MLT + BiDir for a "better" result.

Simply one of multiple issues with pure PT rendering :/

btw. for blend maps use a gamma of 1 for RGB maps and 0.656565 for grayscale

[PureSpider]

btw. for blend maps use a gamma of 1 for RGB maps and 0.656565 for grayscale

didn't you mean gamma of 1/2.2 = 0.454545...?

[Zom-B]

btw. for blend maps use a gamma of 1 for RGB maps and 0.656565 for grayscale

didn't you mean gamma of 1/2.2 = 0.454545...?

Actually not... I took my values from that experiment:

http://www.indigorenderer.com/forum/vie ... 12#p115212

[zeitmeister]

Oh dear,

MLT-BiDir did the trick... alright.
Thank you!
And thanks for the reminder with the special grayscale-gamma...

[Zom-B]

MLT-BiDir did the trick... alright.

Since no optimizations where done for MLT since years, its quite slow compared to PT...
That Firefly situations becomes quite annoying if you like to render trees with blends for the leafs:
http://www.indigorenderer.com/forum/vie ... 73#p116273

And thanks for the reminder with the special grayscale-gamma...

Remember that this is related in what color space your texture is saved in, not how it looks.
Your textures that you used here are saved in RGB, so gamma should be @ 1.

Saving BW textures as greyscale saves 2/3 of the RAM usage for it, so its a good idea to do so
(textures get loaded as raw pixel data in RAM, so a 4096x4096 texture eats up 48MB of RAM, no matter delivered as if jpg or Tiff. A greyscale image only eats up 1/3 of the that 16MB. And a Image with alpha (or a badly saved PNG) has 4 channels and uses 64MB!)

[zeitmeister]

The RAM consumption is clear... often I am too lazy to use grayscale images.
But when working with higher resolutions it definately makes sense.