I have a curve with motion and I have a trail node computing the Velocity.

and then I am volumerazterizing that curve so I get a VDB, but how do I make sure the vdb volume get the velocity so it can be blurred at render time?

thanks.

there is couple of ways , maybe simpler way is convert your curve to geometry via Polywire , Then use VDBfromPolygon to convert it to VDB volume , Then you can use Surface Attribute section in the VDBfromPolygon node to export your v attribute to the VDB.

thanks sadjad, works, now I am a little stuck,
I want to use the vector of the uv geometry and stick that into a ramp parameter.
I can do it with nodes and see the code in vex and looks something like this

// Code produced by: vectofloat1
vop_vectofloat(uv1, fval1, fval2, fval3);

// Code produced by: ramp1
ramp_the_color_space = “rgb”;
ramp1 = spline(ramp_the_basis_strings, fval2, ramp_the_key_values, ramp_the_key_positions);

// Code produced by: bind3
stroke_time = ramp1;