Difference between RGB Curves and Vector Curves?

Vectors have three components. Colors have three components. So is there any real difference between the RGB Curves node and the Vector Curves node? Of course the one is meant for colors and the other for vectors, but does it really matter?

Sure the RGB flavor has an extra “C” button, but besides that, what is different?

Can I plug color (yellow) data into a Vector Curves node, and connect its output (violet) into some other node taking color? Well of course I can but - will it work as expected free of trouble? Is this kosher? Will my evil deeds come back to haunt me later?

Similary, sometimes I want to “mix” two vectors - is this a fine thing to do, to use the Color Mix node with its yellow i/o dots, taking data from and outputting to violet-dotted i/o ports?

Generally, what kind of trouble can I get into connecting mismatched color i/o ports?


I don’t really see a direct answer in your link JA12, but perhaps I’m blind.

In short, and as far as I know, there is no practical difference.

Both colours and vectors are 3 (or 4) channels and can range from negative infinity to positive infinity (although not actually infinity due to floating points)

You can connect any colour socket into any other colour socket (with the exception of shaders (green)) and all conversions will happen automatically if necessary.

It’s not. Should’ve posted it in the other thread the op started.

Please keep your related question threads together for your own and everyone’s convenience. And since Greg has popped in I don’t have to find the link to his site (bottom of his post) where you can find info on the mighty node wrangler add on now combined with nodetools but still the site tells you how to use it.

3 channels of value is the most right now in cycles. The C channel is not separate but a convenience as far as I can tell. Alpha is not a fourth channel in Blender’s node system. HTH.

The most recent documentation will always be the wiki: http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Nodes/Nodes_Efficiency_Tools

This is true for material nodes only, there are of course alpha channels in the compositor (and probably texture nodes, which I don’t use)