Question regarding welding two planes together

loggie24

Hi. I have an annoying problem, the reason it's annoying is because it worked perfectly the first time i did it and now i can't seem to reproduce it at all. What i'm basically trying to do is weld two a total of 4 vertexes together, a picture illustrates it better than words.. 

As i said earlier it worked the first time i did it, and i'm almost 100% sure i did it the exact same way. I'v tried xform, flipping the polygons, using editable mesh (which works but still leaves one vertex not welded). What i'm i doing wrong?

huffer

3dsmax doesn't let you create non-manifold meshes - aka that edge will be shared by three polygons. You can delete one of the polygons on the top plane, adjacent to the edge, and the weld will work (if normals face the right way); or depending on what you want to do, if you want to create a ceiling and wall, add a shell modifier for thickness, cut, create topology to form a continuous cage, etc. For the record, in Maya you can weld them, but a non-manifold mesh doesn't really help anything.

AtticusMars

I may be wrong about this (so anyone who knows for sure can correct me) but as far as I know Max will not allow you to create this kind of non-manifold geometry (in which adjacent faces are pointing out in different directions, with welded vertices)

Assuming that you have backface culling turned on in this screenshot, you would need to delete this face in order to weld those verts.



You could essentially "fake" it by adding more geometry, creating the hole you need, then snapping the verts on top of each other. But if you were going to do that I'd just suggest snapping what you have without welding.

Edit: Huffer beat me too it, but hopefully the screenshot helps anyway

loggie24

Thanks guys. It's wierd because as i said i did it successfully once (and i know it welded properly because otherwise i would have gotten errors in engine).. I'm just trying to figure out what i did then.

And just so you guys know, it's for a flower. The vertical plane is for the stalk and the horizontal is for the flower. The reason they have to be welded is for the wind system to work properly otherwise the horizontal plane will be static (it's a pain in the ass)..

AtticusMars

Well like I said, there are ways to get the same result, it just requires additional geometry.

I don't have max installed but you could try deleting the face, welding the verts, then filling the face again with the create polygon or bridge tools. Dunno if that will work, you might have to just go with additional geometry and overlap the verts.

loggie24

Well, thanks for the answers. Luckily enough i did find a fix. Since editable mesh allows for non manifold edges i worked with an edit mesh modifier and exported it as so which worked greatly

Chhers!

Eric Chadwick

Usually for vegetation systems you don't need to weld anything. Just interpenetrate slightly.

Low-res plants are meant to be duplicated a ton and seen from a distance, so separation or penetration won't be seen.

I'm curious, what engine is this for?

loggie24

Eric Chadwick said:

Usually for vegetation systems you don't need to weld anything. Just interpenetrate slightly.

Low-res plants are meant to be duplicated a ton and seen from a distance, so separation or penetration won't be seen.

I'm curious, what engine is this for?

CRYENGINE. They need to be welded otherwise they won't work with it's "automerge" system, which basically is a feature that merges all vegetation into large groups saving lots of drawcalls. Only 1 element is supported per object.