How to make the group by the color range ?

[ghang]

Hi all

how to make the group by the color range ?

for example i want the primitive group that the RedColor of RGB is in range 50 - 150

e.g : color_(50-100)_0_0

eg: color_(50-150)_(0-255)_(0-255)

I know I can sperate the color group with partition node, but after that i want to select the range by color group, how can i do that ?

thanks

question_of_group_RED.hipnc

[edward]

e.g : color_(50-100)_0_0

eg: color_(50-150)_(0-255)_(0-255)

Well, first of all, colour values in Houdini are not in the range 0-255, but in the range 0-1. So instead of 50-100, you want values like (50/255) to (100/255). Then you can just do stuff similar to

$CR >= 0.2 && $CR <= 0.4 && abs($CG) < 0.0001 && abs($CB) < 0.0001

[ghang]

Well, first of all, colour values in Houdini are not in the range 0-255, but in the range 0-1. So instead of 50-100, you want values like (50/255) to (100/255). Then you can just do stuff similar to

$CR >= 0.2 && $CR <= 0.4 && abs($CG) < 0.0001 && abs($CB) < 0.0001

Oh，thank you very much