Designing for 3d print has its differences compared to designing for animation. Those differences are driven by the rules of nature/physics of the physical world.
Thus, there are some basic rules to take under consideration when designing for 3d printing.
- Objects must be closed/watertight
- Objects must be manifold
You should always make sure that your model is manifold. Manifold in simple terms means that no edge is shared between more than two faces. If you need a more detailed explanation you can have a look at this article. If you wish to check and correct your model regarding being manifold, you can use netfabb.
- Correct normals
You should always make sure that your models normals are correct. This means that all the normals on your model are pointing in the correct direction. If your model has inverted normals we won’t be able to print because our printers cannot determine the inside or outside of your mesh. If you are not certain about this, you can easily check it and correct if necessary in Meshlab or netfabb.
Don’t forget to take into consideration the gravity when designing for 3d printing. Since your model will take a physical form it will obey to the rules of physics. This means that you should be cautious about the balance/center of gravity of your model if it needs to stand. For example If you want to print a figurine it should be able to stand on its own, if this is not possible you can design a base to keep it standing. You can easily analyze the stability of your model in Meshmixer.
- Size and Wall-thickness
You should always make sure that size and wall-thickness of your model complies with minimum requirements of the material you have chosen to use. You can find detailed guides on each material in our material hub. If you are not certain about your wall thickness, you can check and correct it in Meshlab or netfabb.
- Compensate for smoothing modifiers
When designing for 3d print, keep in mind that 3d printers don’t read smoothing modifiers. In order to achieve the same result you just have to sub-divide your mesh. Most 3d design software have the ability to sub-divide the mesh.
- Polygon limit
Another important issue you need to take under consideration when designing is to keep you polygons under 1 million. Models with extremely high polygon count are useful to animation and other industries but not to 3d print.
A high polygon count is needed in order to achieve a smooth and detailed result but there is no need to over exaggerate since the models are relatively small and such fine detail won’t be visible to the eye.