I'm quite new to python and drivers. I'm writing a rather complicated scripted expression inside the driver-area and I need to repeatedly use a long number sequence. Would it be possible to first store this number inside a new variable and then refer to that variable instead of the number?
The driver namespace
Can add functions and constants to the driver namespace
import bpy def func(a, b, c): return a * b * c m = 9.4443299912 bpy.app.driver_namespace["f"] = func bpy.app.driver_namespace["m"] = m
Run the script above, (copy & paste into text editor hit Run Script button,) to make the new members available to the driver namespace. To make it autorun when file is loaded, give the text block a py extension and check the Register checkbox on RHS of text editor header
Can now consider
m in a driver expression to be a named constant like
Use in a driver expression like
f(m, m, m) Can be typed directly into a field by preceding with a hash
# character. Once the expression is a driver (purple) on editing expression there is no longer a need for
There are a number of functions and properties etc already defined to the namespace, a sample of python console output.
>>> for k, v in bpy.app.driver_namespace.items(): ... k, v ... ('asin', <built-in function asin>) ('asinh', <built-in function asinh>) ('atan', <built-in function atan>) ... ('pi', 3.141592653589793) ('e', 2.718281828459045) ... ('f', <function func at 0x7f8f18d34c80>) ('m', 9.4443299912) ('frame', 1.0)
frame is the
EDIT: would like to see a "sub expression" driver variable type where you could do this for scalars, or using other defined variables. Fitting everything into the scripted expression can be a PITA.