Attaching an object to a face / vertex

[Adam H. Stewart]

I'm working on a fish model for a game on the upcoming journey 3D DVD. What I am trying to do is attach an object ( namely and eyeball ) to a skinned mesh. I am using 3dsmax 9 and the skin modifier. I vaguely remember a modifier for doing this, but cannot seem to find it now - any idea's ?

Thanks a million as always


Adam

[LarsSonparsson]

Skin wrapper could work.

[RErender]

I usually use a position script controller on the child object

getvert $'parentobj' 109

Where "parentobj" = the mesh you want o follow and "109" is the vertex number you want it to follow

[jonahhawk]

An attachment controller will do the same thing. It attaches the object to a single face on the source object and then uses barycentric coordinates (learned that from Bobo's DVD) to position the object within the face. You can cycle through the face numbers or simply type it in if you know which one you want.

Different combinations in the A and B slots will give you one of the three verts and lock it on there pretty well.

[jonahhawk]

Cool!

I haven't used the position script before. What is the rest of the code to get it to stick to the vert over time as the mesh deforms? some sort of loop to get it to update and check the position at each frame?

The differences from the Attachment Controller are that getting the object to track normal to the surface would require more scripting (I'm slooooowly learning this from above DVD). Also that bit of code requires that the source object be an Editable Mesh.

If the source object is named Sphere01, for editable poly the code is

polyop.getvert $Sphere01 109

[RErender]

Cool!

I haven't used the position script before. What is the rest of the code to get it to stick to the vert over time as the mesh deforms? some sort of loop to get it to update and check the position at each frame?

The differences from the Attachment Controller are that getting the object to track normal to the surface would require more scripting (I'm slooooowly learning this from above DVD). Also that bit of code requires that the source object be an Editable Mesh.

If the source object is named Sphere01, for editable poly the code is

polyop.getvert $Sphere01 109

It evaluates at every frame so no more code is needed, I haven't tried the attachment controller, will give it a look.

[jonahhawk]

ah now I see. It doesn't update the position until the timeline is scrubbed. I kept rotating the parent and the child didn't move. Odd.

Does this happen with your setup as well Eric?

That is pretty fun to play with though. Adding an orientation constraint to the rotation of the child seems to help the updating as I do anything to the parent. This is a great little tip. Thanks!

[Adam H. Stewart]

Sweet

Sweet - thanks a million I can't wait to give these a try

Thanks again

[trixian]

One should maybe point out that the attachment controller also orients the object to the triangle in question, while the script doesn't.

[jonahhawk]

...

The differences from the Attachment Controller are that getting the object to track normal to the surface would require more scripting...

Isn't that what I said?