ch

float ch(string channel)

float ch(string channel, float time_in_sec)

string ch(string channel)

string ch(string channel, float time_in_sec)

float ch(int op_id, int parm_index, int vector_index)

float ch(int op_id, int parm_index, int vector_index, float time_in_sec)

Evaluates a channel (or parameter) and return its value. The time is specified in seconds, not in frames. If you don’t specify the time, the function returns the value at the current time.

Houdini includes several functions to evaluate channels/parameters of different types.

To get a float or string without needing to know the parameter type, use ch.
To get a float, use chf.
To get a string, use chs.
For integer parameters, use chi
For matrix type parameters, use ch3 or ch4.
For a ramp parameter, use chramp or chrampderiv.
Use chid to get an op_id, parm_index and vector_index to evaluate the channel without having to do string resolution.

Examples

examples

// Get the X transform of the box1 SOP at 1.5s into the animation
float tx = ch("/obj/geo1/box1/tx", 1.5)