Repair an STL File for 3D Printing

In this part of the tutorial, you will learn how to repair an STL file for 3D printing if the file has been badly modeled. As an example, we will use the bridge with a car and a sphere inside a box on it that we created in the first part but this time it has been very badly modeled.

You can retrieve this part of our tutorial in video:


3.1. Check Mesh

The first thing to do is to go into the Facets tab and select Check mesh in the Clean Up Section. Then, by clicking on the mesh you want to check, you get all the errors that are detected in your mesh. Here we have:

  • An object with multiple pieces

  • A self intersecting mesh

  • An over connected mesh

  • Non manifold vertices

These two last points are linked and basically mean that there are non manifold parts in the mesh.
SpaceClaim-33-Check_BbPh0u6.png

We are going to solve these issues one by one.

SpaceClaim-36-Separating_Parts_Pos2Snr.png

3.2. Separate Parts

First, we are going to separate all the pieces in this mesh by hitting Separate All in the Organize section.

SpaceClaim-34-Separating_parts_Jo9ZxRE.png

The initial mesh is now separated into 6 smaller meshes. There are two different types of icon in the structure tab: meshed cube and meshed surface. A surface icon indicates that the corresponding mesh needs repairs.

SpaceClaim-35-Separating_parts_fysAPql.png

So we check the first problematic mesh, which is the car, and the Check Mesh tool indicates that there are multiple pieces and non manifold parts.

3.3. Repair Non Manifold Parts

By zooming in, we can see that the 4 square wheels are linked to the body only by edges which is not possible in real-world objects.

SpaceClaim-37-Reparing_non_manifold_1Wpt9PO.png


You might think that the Auto Fix tool would solve everything for you but this is actually not very efficient. 

SpaceClaim-38-Repairing_Non_manifold_0hgXloJ.png


Here, the problem is not really solved as the car's body is still linked to the wheels only by edges.  


SpaceClaim-39-Non_manifol_repairing_LxKremP.png


So we need to solve this problem manually. To fix this issue, we can convert this mesh to a solid with merged faces. Choosing separate faces would create one solid for every single face.

SpaceClaim-40-Non_manifold_repairing_PH4orHe.png


By pulling the body down, we make it a manifold solid.


SpaceClaim-41-Non_manifold_repairing_lHdLyJA.png


When we turn it back to a mesh, we have no issues anymore according to the Check Mesh Tool.


SpaceClaim-42-Non_manifold_repairing_JjVwhyR.png


3.4. Repair Intersection Issues

Now, we need to solve the issues linked to the other surface mesh. The Check Mesh tool indicates that there are multiple pieces, self intersecting objects and non manifold vertices.

SpaceClaim-43-Repairing_Intersection_N8Dmkuu.png


By clicking on the Intersections tool and then on the mesh wewant to clean up, intersecting parts appear.  


SpaceClaim-44_Repairing_intersection_3l4UH9t.png


When you hit the green check box, SpaceClaim solves the intersection issues.

3.5. Spot and Fix Modeling Errors

It seems that all the meshes are clean.

SpaceClaim-45-Modeling_errors_mN6CY3y.png


But keep in mind that SpaceClaim can only spot mesh errors and not modeling errors. For instance, the bridge support does not touch the arch and is thus useless for the solidity of the structure.  


SpaceClaim-46-Modeling_errors_B8n5AY1.png


We convert the support to a solid and pull it until it is in the middle of the arch. By converting it to a mesh again and using the Merge tool in the Modify section, we avoid any self intersecting issues.


SpaceClaim-47-Modeling_erros_vl148Vx.png


The only remaining step is to combine meshes that are in contact. At the end, we have two remaining meshes: the sphere that is inside the box and the rest of the bridge. Our STL file is ready to be printed.


SpaceClaim-48-Modeling_errors_vCUcKAA.png