tandava.ananda Posted February 28, 2015 Share Posted February 28, 2015 (edited) Hi, I'm looking to change the color values of copy groups using information coming from a CHOP network. I've gotten it so that a single channel can affect a single copy group, but I don't know how to make it so that each channel changes the color paramaters of seperate copy groups. I could set up 127 color nodes and select a different group in each one, but I know that's not how you're supposed to work in Houdini. In the included file, the Channel surface node provided a simple method for CHOPS channels changing the position of points on a line. But my methods of using attribute scope Cd(1) to affect color changes on the copy groups crashed the program every time. It's taken me ...hours... to get to this point. I'll keep plugging away, but if anyone knows a solution, it would be appreciated. HoudiniColor.zip Edited February 28, 2015 by tandava.ananda Quote Link to comment Share on other sites More sharing options...
edward Posted February 28, 2015 Share Posted February 28, 2015 Sounds like you might have been hitting a bug that has been fixed? From the journal Thursday, January 29, 2015 Houdini 14.0.229: Fix crash when encountering missing tracks in the Channel SOP when using animated mode. Quote Link to comment Share on other sites More sharing options...
tandava.ananda Posted February 28, 2015 Author Share Posted February 28, 2015 Neat. It doesn't crash anymore, but I still can't get it to color the individual copy groups. Instead of using P(1) to change position on the Y axis, I'm trying Cd(1) to change the colors on the green spectrum. I'm going by what I gather from the Help module: P Point position (X, Y, Z), 3 valuesPw Point weight, 1 valueCd Point color (red, green, blue), 3 valuesAlpha Point alpha, 1 valueN Point normal value (X, Y, Z), 3 valuesuv Point texture coordinates (U,V,W), 3 values but when I MMB the Channel SOP it tells me "Error: Unknown attribute Cd.I've edited the attached file in the original post to show the current workflow. Sounds like you might have been hitting a bug that has been fixed?From the journal Quote Link to comment Share on other sites More sharing options...
edward Posted February 28, 2015 Share Posted February 28, 2015 Maybe you need to create the Cd attribute first before the Channel SOP. Quote Link to comment Share on other sites More sharing options...
tandava.ananda Posted February 28, 2015 Author Share Posted February 28, 2015 I know what you're saying I need to do, and it makes sense, but I can't figure out how to do it right. These are my first steps into Houdini so everything is new. I tried using an Attribute Create node and then referencing it in the Channel SOP but I'm clearly not doing it right. I've been combing the internet and the help guide trying to find an example of anything remotely close to help me make sense of this, but nothing yet. Quote Link to comment Share on other sites More sharing options...
edward Posted February 28, 2015 Share Posted February 28, 2015 The cook errors disappeared as soon as I insert a default Color SOP in between your duplicate1 and point_position nodes for me. Quote Link to comment Share on other sites More sharing options...
tandava.ananda Posted March 1, 2015 Author Share Posted March 1, 2015 Awesome, thank you. I knew it was an easy fix, but it drove me to wit's end. Thanks again. Quote Link to comment Share on other sites More sharing options...
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