About Preparing Models for 3D Printing
When you prepare your models for 3D printing, you create a tray assembly, using the Additive Manufacturing application. You perform all the required operations before printing the models, such as adding models to the tray, positioning them, and scaling them.
Models that are visible on the tray will be printed. Hidden items are not printed.
Creating a Tray Assembly
You can create a tray assembly in one of the following ways:
• When you have a model open and you click > 
Print > 
Prepare for 3D Printing, a tray assembly is created and the model is placed on the tray.
Print > Prepare for 3D Printing, a tray assembly is created and the model is placed on the tray.• When you create a new tray assembly file as follows: click > 
New, and in the New dialog box, under Type select 
Manufacturing and under Sub-type select Additive Manufacturing. The Additive Manufacturing application opens.
New, and in the New dialog box, under Type select Manufacturing and under Sub-type select Additive Manufacturing. The Additive Manufacturing application opens.When you create a tray assembly, you can perform printability checks and other analyses. The analysis is based on the scaling you apply in the Additive Manufacturing application. You can save the file for future use or you can print it, if you are connected to a 3D printer. Before you print it, you can set up the quality of the printed model surface on the 3D Print tab, or you can skip this step and directly print your models.
Information Stored in a Tray Assembly File
A tray assembly is a type of an assembly file. A tray assembly file stores the following information:
• Models that you placed on the tray, under the Model Tree
• Location and orientation of the models on the tray
• Scale of the models on the tray
• Copies of the models you created
• 3D printer you selected
• Support structures you generated, when you are connected through a Materialise build processor
• Lattice penetration into the solid wall
• Colors you applied to the models in the tray assembly
• STL settings you applied to each model on the tray
The changes you apply to models in the tray assembly file do not modify the original parts and assemblies. For example, if you scale a model inside the Additive Manufacturing application, it does not affect the actual size of the model. Although you can create constraints when you assemble the tray, the constraints are removed when you exit the placement tool, to allow quick movement of the models on the tray.