Mirror based on the parent objects local axis

[ompalumpa]

Hello,

I need to mirror an object based on the local axis of another object but not have it parented to it. If I do have it parented and mirror the parent (-1 scale) it puts the child eactly where I want but I don't want this to be parented. This needs to be realtime, as like driver with an expression. To parent the child then mirror the parent and unparent works fine but it's not realtime - if you know what I mean. I need something that does the same but doesn't parent. Please help

[jessec]

I'm not sure I follow. But couldn't you simply point and orient constrain an empty null group to the object, group the thing to be mirrored under this, and then mirror the top previously empty null group, and then unparent the mirrored child object from it?

[ompalumpa]

Thank you for your help.

I've tried a few things with constraints but they don't quite do what I am after. Lets start over again - I'm writing a script that helps with lighting.

I pick a point on a surface and automatically a light will be positioned to create specular at the surface point. This is to replicate the place highlight tool from 3dsmax.

If I use a normal constraint to constrain a box to an object that is "Live" I can move the box over the surface. Now if I mirror the position of the camera around the box's local axis I'll get the point of where the light needs to be to create the specular at the point of where the box is constrained. With parenting this all works well but as soon as I move the box (changing the position that needs specular) it doesn't maintain the light in the correct position - a little hard to explain.

I can almost do this with parenting but what I need to do is for a child object not to move position when I rotate the parent. It

[jessec]

Well, in Maya at least, I know you could just do a point constraint, and it does exactly what you're asking, passes on the location to the object being constrained. I'd assume there should be something comparable in Max?

[sparky]

where "n" is the original and "m" is the non-child you want...

N posY = M posY(-1)
or X or Z, depending on what axis you want to mirror. THe syntax is probably wrong, but I think this is the general gist.