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Issue:

An error message stating that the input mesh must be manifold I’m trying to create a Quad Mesh, but I keep getting the error: “Input mesh must be manifold.”

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Applies to:

  • Quad Meshing
  • Export to CAD
  • Mesh export

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Cause:

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What is Manifold?

A topological space that resembles Euclidean space up close. For example, the Earth looks like a plane when you are standing on the surface but from far away it is actually spherical. Manifold objects are continuous without any beginning or end. An example of this is a sphere or a cube. A non-manifold object would be a Plane. Non-manifold geometry can’t exist in real life, which makes this error one we need to solve if we want to 3D print our part.

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Why would a mesh be non-manifold?

A mesh can be non-manifold due to many reasons. Some of the most common occurrences are:
  • An edge connected to more or less than two faces (including internal faces)
  • Separate regions connected through a single vertex
  • Loose geometry (discontinuous)
  • Plane normals pointing in opposite directions for adjacent faces

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Check to see if your mesh is manifold

To check if your mesh is manifold or not, click on the info (?) panel and go to Properties. There will be a property called Manifold. If it says False, then it is not manifold and if it says True, then it is. A mesh from implicit body properties panel with the manifold property highlighted

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Solution:

If your mesh isn’t manifold, you need to refine your mesh further. This can include using blocks like Remesh Surface , Refine Mesh , Simplify Mesh by Threshold , Simplify Mesh by Amount , or editing the Adaptivity and Feature Size. Take a look at this article for further methods and tips on refining meshes. If your mesh is still non-manifold after trying these steps, you may have to go back to your original part in a different program and try cleaning it up. Sending it to another program like Magics for cleaning up may also be necessary. If you are trying to create a Quad Mesh using theQuadrangulate Mesh block, you will always want to use one of the refinement blocks mentioned above. Inputting a Mesh from Implicit Body or Mesh from CAD Body block will most likely cause an error when used without a refinement step.

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More on this topic:

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Keywords:

cad error mesh meshing export property quadrangulate quad refine simplify threshold amount vertex input must be manifold euclidean topological space false plane discontinuous normals