When designing a 3D model for rendering or animation, it is not necessary to overly concern yourself with its real-world functionality. However, when it comes to 3D modeling and digital sculpting for printing, there are certain factors that need to be taken into consideration. Here are some common challenges to keep in mind:
Ensuring a watertight mesh:
A watertight mesh refers to a 3D model that has closed edges, forming a solid volume. In other words, if you were to fill the geometry with water, it should not leak. This characteristic is essential for creating a manifold 3D model. One effective way to achieve this is by checking the "normals" of your mesh and ensuring they are all outward-facing. If any normals are flipped, the 3D printer may interpret them as holes. It is important to thoroughly inspect your model for any internal geometry that might have been unintentionally left behind during the Boolean operations.
Here's what a model with normals facing out looks like:
No internal geometry has been left behind due to booleans:
Removing non-manifold geometry to ensure you have a manifold 3D model:
Non-manifold geometry refers to any edge that is shared by more than two faces. This situation typically arises when a face or edge is extruded but remains in its original position, resulting in two identical edges directly overlapping each other.
In the following example, there are two cubes sharing an edge. Non-manifold geometry is present because this particular edge is shared by four faces:
When your model contains non-manifold geometry, it can pose difficulties for our printers to interpret the file correctly. However, you can typically resolve this issue within your modeling program to ensure that your 3D printing results in a manifold object.
To ensure the successful printing of your manifold 3D model, it is important to review the Material Guidelines provided. Each material, and often each finish, possesses unique production processes and specific physical properties. The Material Guidelines serve as a comprehensive resource to assist you in understanding the requirements for each material we offer.
The dedicated page for each material within the Material Guidelines provides essential guidelines such as bounding boxes, required thicknesses, and escape hole requirements. These guidelines offer valuable information to help you accurately model for each material, ensuring a smooth printing process..
Here are the individual sets of guidelines for each material: