[Closed] Illegal self-reference

 struct test 

(
val = [0,0,0],
 
fn testFn pos = 
	(
   val += (pos)
   pos += val
	),
endOfStruct
)
test01 = test()

you could instance a struct with a updating varible called by a function. The function could look at the position of a weak referenced object. So the object has a position script with a script controller and the position_xyz()

the script controller references a its own position_xyz() in the stack as a weak reference.
A weak reference can be assigned to an object with a custom attribute.

Thanks for the help, I will give this a try! I’m used to having it passed as an input variable in XSI so this is a bit of a foreign concept to me.

A weak reference is essentially a node callback to an object. Its called when the object changes, unlike the .this construct or node variable which gets evaluated every time the script gets evaluated even if nothing changes.

To give an object you need to assign it a custom attribute with either a maxObject type parameter or a maxObjectTab if you want a array type – these are paramBlock2 types. Once an object has this custom attribute, you can reference itself to this paramater type by:

$theObject.attribute (name of the maxObject parameter) = nodeTransformMonitor node:theObject forwardTransformChangeMsgs:false)

now typing in $object.attribute.node will give a reference to itself. A good tutorial for this is to assign two objects with a weak reference. Add a position list to each and position_script() then a bezier_position() to each.

In the position script of each, have it reference the other objects bezier position in the list as a reference to it e.g:

a.attribute.node.pos.controller[2].controller + offset position (add this offset only to one of them) This will make two object control each other a > b and b < a. Its essentially the same as instancing a controller but give you flexibility.

Thanks for the comment Eric btw

cheers,

I’m using weak referencing on every character to do things like store all the nodes of the entire rig in a control panel. If you were to try and do this with nodes you would get a rig that would move very slowely and probably throw a pile of circular reference errors. Have a look on my site at http://paulneale.com/tutorials/Scripting/weakReferences/weakReferences.htm for a tutorial on how to set it up and use it. Also if you have Maxine from the Max 8 discs she uses weak referencing to store nodes that are used when you execute tools like the pose mirroring.

Thanks for the tutorial Paul.
You mention in the intro that weak references have been added in Max 8. At this point I have to use max 7 unfortunately. Is there a work around to achieve the result that I want without cyclical errors in version 7?

There is no weak referencing in Max 7. You will have to store nodes as nodes.

I gave this a try tonight. I stored a regular node as a custom attribute but when I call it from the script controller I still get the Self-reference error

I would have to see what you are doing to know more about how to help you.

You cant call a node directly in a script to reference itself, I’ve tried this too – and the only way i know is referencing a weak reference to one of it controllers. For example:

position_list(1)
position_script(2)
bezier_position(3)

position_script(2) references bezier_position(3) – If theres a way around that other than build variables and struct instances I’d like to know too.