topic Re: Remesh and Generate Complex Issues in Meshmixer Forum

Remesh and Generate Complex Issues

Anonymous — Tue, 27 Nov 2018 15:48:32 GMT

I have a rectangle I want to cut for separate color, but the mesh is only four pieces.

So I resmesh ....

This creates a blue line around the rectangle, I assume that's a new group. When I face group and generate complex, it appears to select the whole rectangle and not just the facegroup ....

Can I still assign a color to just the face group area? I actually need three color areas in the rectangle. Do I need to somehow break the group?

Re: Remesh and Generate Complex Issues

Anonymous — Tue, 27 Nov 2018 16:19:50 GMT

Think I have a clue. Read MagWeb response to zeischang - https://forums.autodesk.com/t5/meshmixer/problem-with-separating-parts-for-multicolor-3d-print/td-p/8386023

Understand A TINY BIT of the explanation. Running make solid. Seems to have fixed for now. Thanks MagWeb

Re: Remesh and Generate Complex Issues

Anonymous — Tue, 27 Nov 2018 20:07:51 GMT

The blue line doesn't mean a face group but an open boundary. The parts of the mesh are not connected any more.

FaceGroups are indicated with different colors (if you are in MeshColorMode: FaceGroups , see: Preferences or Hotbox)

Your open boundary is the result of a partial Remesh in Free- or RefinedBoundary mode without allowing a Transition. If you use these modes you need a transition as otherwise they place more (or less) vertices at the selection's boundary. This (without Transition) means that MM needs to break the mesh as the triangles outside the selection are not changed and a Tri can't have more than exactly three vertices.

Without any Transition you need to use FixedBoundary mode.

MakeSolid is great but owns disadvantages too. E.g.: It's a global operation on the total object. If there are hard edges or small details you'll need a high resolution all over (high file size, long computation times). Remesh instead allows to increase densities on regions only which actually need more density and the rest of the mesh isn't touched at all....

Re: Remesh and Generate Complex Issues

Anonymous — Tue, 27 Nov 2018 21:33:41 GMT

That makes sense. The problem I have is it doesn't seem to want to let me generate complexes and splits correctly. I want six boxes inside. When I try to generate faces, complex and split; it seems to give me just one big box.

Re: Remesh and Generate Complex Issues

Anonymous — Tue, 27 Nov 2018 22:18:04 GMT

Dual color printing or more colors?

If there are several concentric square groups and you want a dual color print:

Do not use AutoGenerate. This spans an interior surface over the outer seam of the group (same as if you'd double click on each boundary which gets orange hovering over the boundary)

Instead hover the cursor over a group > The whole group gets orange. Double click it > This results in an offset interior surface (as if you'd extrude the group to the inside). Do this with each second group...

Re: Remesh and Generate Complex Issues

Anonymous — Tue, 27 Nov 2018 22:34:49 GMT

Some images:

The groups:

After double clicking the cyan, purple, red and yellow group in GenerateComplex:

After splitting the complex and combining the regions to be printed in red (transformed for visualisation):

Re: Remesh and Generate Complex Issues

Anonymous — Wed, 28 Nov 2018 14:32:20 GMT

Thanks, will experiment with that.

Re: Remesh and Generate Complex Issues

Anonymous — Wed, 28 Nov 2018 14:35:52 GMT

How did you make the rings? What is your suggestion for making rectangles with sharp corners?

thanks

Re: Remesh and Generate Complex Issues

Anonymous — Wed, 28 Nov 2018 16:13:51 GMT

The issue I'm having is that when I go to generate complex, the selection is inverted. In this picture, what I want is the single rectangle, but it has selected the outside ring. It won't generate for the rectangle. Even if I double click the rectangle, all I get is the ring.

Re: Remesh and Generate Complex Issues

Anonymous — Wed, 28 Nov 2018 19:27:20 GMT

Too **** weird. I select an area, INVERT THE SELECTION, create facegroup then complex; and i get what I want. The rectangle area created. What is going on?

Re: Remesh and Generate Complex Issues

Anonymous — Wed, 28 Nov 2018 20:23:06 GMT

I made the concentric rings using a circle STAMP. To get the center point of the rings I dropped a Pivot somewhere on the surface. Now drawing a stamp and starting to drag near the pivot the stamp's center snaps to the pivot.

Be aware of the SnapDimensions checkbox at the bottom of the tool's flyout. Enabled the possible sizes and rotation angles are restricted to certain increments. The increments' scale is related to the last used snapping settings in Transform (but not equal).

Start stamping the biggest diameter flowed by the 2nd biggest, aso....

To get a rectangular group you might use the square stamp or create a custom stamp in SELECT.

Another possibility is to use PlaneCut (in EDIT or in SELECT/Edit) in CutType = SliceGroups. Note: Doing such a cut on a selection will cause small open boundaries at the border of the selection. You'll need to repair these errors using ANALYSIS/Inspector.

----

I see you separated a ring of triangles. Be aware that if you construct a complex on such an separated part you can't weld the complex to the rest of the mesh AND keeping the complex information further on if the rest of the mesh isn't a complex (you'll loose the Complex flag this way and the interior surface will give a non-manifold issue)...

----

This said:

The Complex tool renders valid group boundaries in black. In case there are two options of a valid boundary but both are not possible (as in your case) MM chooses the group with the lower FaceGroupID. In your case: White is the group "zero". All other groups get their number by history. The first group you create gets something like "1" as ID, the second "2" ....

To change the behaviour of which group boundary is treated as valid in case of a conflict you simply need to change its order. In your case: Select the white group (ID = "0") after you did the orange (ID = "X") and do Modify/CreateFaceGroup. This creates a new group (ID = "X+x" - means done after "X"). Now the Complex tool will highlight the boundary of the orange group and create the interior surface there.

As said: Your example can't work if you think about joining stuff later....

Think I should write a book 😉

Anyone interested?

Re: Remesh and Generate Complex Issues

Anonymous — Thu, 29 Nov 2018 14:39:28 GMT

Had to read it three times, understand most. Thanks