Houdini VEX Attributes

April 20, 2020

To access a point’s attributes:

@Cd = point(0, "Cd", @ptnum) // 0 is the input, or use 'geoself()'

You can access point , prim , vertex, etc. See here.

Remember that inputs are zero-indexed.

To explicitly cast anything in VEX, use set.

float aFloat = 1.0;
int cols = set(aFloat); // cast 'float' to 'int'
int cols = (int)aFloat; // another way

To set an attribute:

i@order = 1;
@distance = 2.123; // float, implicit cast

If we are not acting on geoself() and changing attributes on another object from e.g. from second input, we can use setpointattrib.

vector color = {1, 0, 0};
setpointattrib(1, "Cd", @ptnum, color); // where '1' is the second input

To get all point attributes, set a Wrangle SOP to run over a detail:

string attribs[] = detailintrinsic(geoself(), "pointattributes");

To get a channel/parameter from any node:

float scale = chf("../box1/scale") // like using 'ch' appended with a type

To access other types, you have chi (int) chs (string) cfv (vector) etc.