Extra Lines Appearing in Geometry

I’m re creating a model that I’d previously built in Maya about ten years ago.

The original Maya model has a clean wireframe and it was convenient to make wireframe printouts for construction plans.

However, when I make the same object in Blender, I get a number of diagonal lines that are undesirable. How do I rid my model of these unwanted lines (highlighted in blue)?

You can select the unwanted edges, press X then select dissolve edge.

As Blutag writes you can dissolve edges, but this will not work for all. There are limitations.

When I do that, I get this menu, but how do I apply it? The edge is still there.

image

You cannot remove all of them. Blender doesn’t support polygons with holes. Per each hole, at least one cut must exist.

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I wonder how Maya can do it without generating edges?
In Maya I can do a wireframe render of a scene and it’s clean.

When I started building the same thing in Blender, I get all these extra lines between holes that look awful when I want to do a wireframe animation.

I don’t know and I don’t see how that is relevant. Blender’s mesh representation does not support holes in polygons - that’s just the way it is.

AFAIK, neither does Maya’s - the edges are still there and they come right back if you try doing anything else with those holes like e.g. beveling them. But like I said, I don’t know how they do that fake edge deletion, nor why would that even be allowed.

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You’re right in that when I apply a bevel to the Maya object, it will display similar lines.
Why I don’t want these lines to appear is because I want a clean wireframe animation.

Perhaps try rendering with Freestyle?

Two disconnected sets of vertices means pretty much two meshes, so you can’t have two meshes in one.

But if you’re interested only in the wireframe then you could make the holes be separate cylinders and parent them to the main object, Then the wireframe will be rendered clean. You won’t be able to render through holes though because they’re no longer holes but that shouldn’t be a big issue for a wireframe mode…

I did an animation in Maya where the objects are rendered solid and then fade to wireframes. Is it not possible to do that in Blender without a lot of jumping through hoops to accomplish it? It seems the method of using cylinders is a workaround for only one mode (wireframe) but cannot be used in the solid mode because it’s not holes.

One way to do it would be to use the freestyle method and in the view layer properties tick the «as render pass» box under the freestyle options. Then you can animate and fade in and out the solid and wireframe/freestyle passes in the compositor with the set alpha node.
I know this is jumping through the compositor hoop, but it is not too bad.

Edit: mmm I can not seem to work out how to fade the freestyle pass with set alpha so maybe not so easy.
There must be some way of doing this with the compositor If anyone has any ideas?

Edit 2
Well this seems to work, a few more hoops!
I had to separate the background (film transparent), I used a simple yellow colour for background.
The node setup for compositor was this:



Maybe someone has a more simple idea!

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Thanks for going to all this effort. It’s a bit over my head though. It’s a bit like wanting to draw a circle, but there’s no circle tool, but you can draw 1024 straight lines and arrange them in a circle.
I need the least cumbersome method because I have to do this to many objects. There’s got to be a way to do this.

Yes I am afraid that blender does not have a decent wireframe node that would make wireframes much easier to render, there is a wireframe node but it triangulates. At the moment everyone uses work arounds.
Another method is to duplicate the mesh delete only the faces (leaving the edges) and use a skin modifier to give it some thickness. You could then fade in and out the objects by mixing their materials with a transparent node and animating the mix factor.
Edit you would still have to delete the unwanted edges!
If you have to do it with multiple objects at once (all objects wireframe at the same time) the compositor method would be faster. If you want them to fade in and out one buy one I do not think there is a simple solution.