Additional methods to assign transparency for PolyJet in GrabCAD Print

Naftali Eder

3 May, 2020 03:39 PM

In our previous tutorial about assigning transparency for PolyJet, we described how the different settings for transparency in GrabCAD Print work and when to use each.

In this tutorial, we will discuss alternative, often more advanced workflows for assigning transparency for PolyJet models.

This tutorial is not meant to be a comprehensive summary of all the ways to apply transparency to a model. Like many other features of 3D printing, the applications for transparency are to a large extent mainly limited by our own creativity and ingenuity.
That being said, here are some other ways to work with the transparent capabilities in PolyJet.

1. Step 1: Achieving Transparency with STL Assemblies

   The same methods that apply to assigning transparency to a single STL file can also be applied to an assembly of multiple STL files. This can be used to create a multi-layered effect with different colors and transparencies within a single model, all within GrabCAD Print.

   There are plenty of creative ways to nest parts inside each other with varying colors and transparency levels. Here are a few examples:  

   

   

   
   

   Note how overlapping colors and differing amounts of transparent cyan and yellow can create green, purple, and red, without those colors being assigned. 

   

   A medical model printed from an STL assembly with transparent assignations.

   
   

   These assemblies would be created in the modeling software and then imported into GrabCAD Print where the material assignments are made

2. Step 2: Assigning a Colored Coating to a Clear Core

   When using VeroVivid materials, GrabCAD Print will automatically assign the transparent materials as a 1mm coating over a white core. You can access the core/coating assignment in the Settings menu and adjust the assignments to your own needs. For example, applying a clear core with varying thicknesses of colored coating over it to achieve different levels of transparency. You can control the thickness of this coating and choose any core material by using the Coating checkbox.

   Within GrabCAD Print, the minimum coating thickness assignment is 0.3mm, and the maximum coating thickness should be 3mm. To go above or below these thicknesses, use step 1 (design the part in your modeling software to meet these requirements). 

   

   This core+coating setting gives you the ability to define thinner color layers and alternative core materials. Below are some real-life examples:

   

   

   Before using any of the above methods for assigning transparency, you can use the color swatch generator. This tool might help you understand how the transparency and colors you select will appear (on or off the tray). Read our tutorial about how to use the color swatch generator.

   This generator is now also embedded into GrabCAD Print from software version 1.40. The same settings and process shown in the tutorial linked above apply to this GrabCAD Print tool:

   

   
   

   
   

   

   
   

   This video explains more about using the tool from within GrabCAD Print.

   
   

   
   

3. Step 3: Import Native CAD Files Directly and Assign Transparency Using GrabCAD Print Settings

   Another way to assign transparency in GrabCAD Print is to import CAD files directly from certain software packages in their native file format, without the need to first convert to STL or save as VRML/OBJ.

   See below a list of file types and the design features that can be assigned to them* using GrabCAD Print settings. 

   

   
   

   This capability means less time, less work, and less frustrating (mis)communication between the person designing the model and the person printing the model, because color/transparency assignments do not need to be made in GrabCAD Print. 

   
   

   *Not all of these features are available for all the file types as many do not support transpancy or texture assignments.

4. Step 4: Importing an Advanced File Type with Transparency Already Applied

   This option is useful for CAD models with advanced material/color assignments, such as those created in Maya or Adobe Photoshop. Advanced programs like these can assign textures and varying degrees of color, transparency, and opacity in one part that can then be imported to GrabCAD Print, via VRML or OBJ.

   For example, the model below had color and transparency along with a wood grain image texture assigned in Photoshop. It was exported as a VRML file into GrabCAD Print. 

   

   Honey drip printed from a VRML file with transparency assigned to a PNG texture file.

   To learn more about adding textures, start here.

   To find out more about working with VRML and OBJ, see this tutorial.  

   
   

5. Step 5: Overriding Color And Texture Assignments in GrabCAD Print

   GrabCAD Print settings can override color, texture, and transparency details previously assigned in the imported VRML file.

   Changes made using digital materials, the alpha slider, the alpha channel, and material assignments can alter the appearance of the model. 

   

   

   Watch a video about this feature here:

   
   

   
   

   
   

    We hope this tutorial, along with our previous tutorial about transparency, helps explain and simplify the exciting world of vivid and transparent colors and enables you to unlock the full capabilities of the PolyJet Design Series printers.

   If you have any questions or comments please leave them below.