Avoid mistakes that occur when designing 3D files for 3D printing on Autodesk Alias

As already mentioned, Sculpteo’s upload limit for meshes is fixed at 1,000,000 polygons, because meshes with more polygons would be difficult to handle. If in the analysis phase you see that your mesh is bigger that this limit, you are provided with two options for reducing its number of polygons:

• By going back to your surface model and re-meshing it with a higher ‘Max Edge Length’ ( Suggested option)
• Or if you are not in possession of the original modeled file, Alias provides you with a feature called ‘Mesh Reduce’ [Mesh>Mesh Reduce], double click to access its information window, choose ‘Fraction’ as the mode and apply the required percentage of reduction, then click the ‘Reduce’ button located at the bottom right.

If your shells have not been properly stitched together during your modeling process, you might see some ‘Boundaries’ appearing on your ‘Mesh Repair’ window, which will be outlined by red lines on your model. These can be easily stitched together with the function ‘Mesh Stitch’ [Mesh>Mesh Stitch]. Double clicking on the boundary—which selects the area around it—and then click the ‘Stitch’ button on the bottom right corner.

The presence of boundaries in your mesh analysis—outlined by the red lines on the model—can also imply the existence of holes in your mesh. You can visibly recognize the difference between two meshes that are not well connected –a boundary that needs to be stitched—and a hole in a mesh. In is this second case you can use the feature ‘Mesh Hole Fill’ [Mesh>Mesh Hole Fill] to manually close a hole.

Simply select your mesh and click on the detected red boundary around the hole, which will automatically be closed. To select a filling type, divigatæe to the information window of this feature and choose ‘Taut’ for planar filling or ‘Faired’ for tangent filling.

When the hole detected in your mesh is defined by two closed boundaries instead of one, like in the next example, the appropriate filling tool is called the ‘Mesh Bridge’ [Mesh>Mesh Bridge].

Select the mesh, and the hole boundaries will be highlighted, then proceed to select the edges of two opposite polygons which will automatically connect the holes. Repeat this operation for all the polygons’ edges that make up the boundary of the hole.

If you see no boundaries on your model but your number of components is still higher than the singular solid parts in it, it means that some shells haven’t yet been unified. Once again, the best option is to go back to your surface model and stitch your surfaces correctly. If that’s not possible, then you have to do it on your mesh.

When these shells have been found, in order to be able to intersect and cut them, you must first have to divide them using the feature ‘Mesh Subset’ [Mesh>Mesh Subset]. This feature uses black dots to select the areas in your mesh that need to be divided from the rest. You can then select with this tool one of the two shells that you want to intersect and press ‘Subset’.

Now that you have divided the incorrect shells, you should be able to ‘Intersect’ them using [Mesh>Mesh Intersect]. Then choose ‘Cut’ [Mesh>Mesh Cut].

Select one shell and the cutting line just created, select which part of this shell you want to delete—the one inside your model—and press ‘Delete’. Do the same for the second intersected shell and now you will have two correct continuous shells that just need to be stitched together with the ‘Mesh Stitch’ feature described in previous sections.

If the tools and techniques just described do not fix your mesh, then trying Sculpteo’s awesome online printing automatic repair tools should be your best option. Simply export your model as .stl, as described above, upload it on Sculpteo’s website and let our repair tools do the rest for you!

The feature ‘Mesh Subset’ allows you to select precise parts on your mesh. This feature can be useful when you need to delete unwanted parts of your already meshed model such as singular faces, or need to divide it into different parts that you need to keep separated.

For example, if you want to delete the embossed Sculpteo logo from the model. You can do this with the active command by selecting your mesh, and choosing a view that allows you to see all the parts of the mesh you want to subset—for the command resets when you move. Next, use a series of dots connected by lines, to define the area.

Some buttons will appear at the bottom right of the screen, choose ‘Select’ to pick the polygons—which become light blue when selected— and then click ‘Delete’ if you want to remove them permanently from your model, or ‘Subset’ to divide them from the rest of the polygons.

If—as in the provided example—you have deleted your polygons, a hole will then be created. Which can then be filled with the command ‘Hole Fill’