feed Cd to color ramp point inside shader?

   2495   2   1
User Avatar
Member
7 posts
Joined: 3月 2016
Offline
Hello!

I am trying to set the value of a color ramp point inside a shader to the value of my Cd.
The parameter is called “rampcolordefault2” and i guess in vex i could have written “rampcolordefault2 = @Cd;”, but this is vops and i just don't know how to set that parameter.Is there any way of doing this?

Thank you!

Attachments:
Screenshot (99)_LI.jpg (849.5 KB)

User Avatar
Member
8043 posts
Joined: 9月 2011
Offline
The ramp cannot take individual inputs as keys of the ramp. You can use the spline vop to evaluate a set of arbitrary inputs as if it were a ramp though. The spline vop unfortunately does not allow specifying key positions, limiting it to ramps with evenly spaced keys. If you want to have the full power of a ramp, you'll need to get crafty with building the arrays that define a ramps keys, positions, and bases. These in turn are evaluated using the spline() function, which is only available as inline code, using an inline or snippet vop.
User Avatar
Member
459 posts
Joined: 10月 2011
Offline
You can control ramps with python though, so you could put together an hda controlling this. Here is some example code to fiddle with.
node = hou.node('/obj/matnet1/subnet1/ramp1')
curve = hou.rampBasis.CatmullRom

pos1 = 0
pos2 = 0.5
pos3 = 1

firstColor = (0,1,0)
secondColor = (0,0,1)
thirdColor = (1,0,1)

newramp = hou.Ramp( (curve, curve, curve) , (pos1, pos2, pos3), (firstColor, secondColor, thirdColor))
node.setParms( {'rampcolordefault': newramp } )

-b
http://www.racecar.no [www.racecar.no]
  • Quick Links