[Python MaxPlus] Modify parameter of an existing object

Rigging
#1

Hi,

I’m trying to modify a parameter of an existing object.

In the documentation , it provides an example of modifying an object:

obj = MaxPlus.Factory.CreateGeomObject(MaxPlus.ClassIds.Sphere)
obj.ParameterBlock.Radius.Value = 5.0
node = MaxPlus.Factory.CreateNode(obj)

It works as expected but that is pertaining to an object that is about to be created. When I used the code to modify an existing one, it throws an error:
RuntimeError: invalid parameter

Here’s the code I use

# Gets the selection of objects. In this case, only the sphere
objList = MaxPlus.SelectionManager.Nodes

for obj in objList:
	obj.ParameterBlock.Radius.Value = 15.0

Is there an additional code I am missing out?

Thank you for looking at my problem.

#2

That’s because you are iterating nodes while the original code was accessing object. If you instead use obj.GetBaseObject().ParameterBlock.Radius.Value, everything will work as expected (provided you test it’s the right class).

1 Like
#3

RE: iterating nodes while the original code was accessing object
Interesting. I never thought there is a major distinction. I initially though the object is in memory but the nodes is in actual scene. So I thought they are just one and the same referring to same thing.

Anyhow, your solution. Works as expected.

Thank you!