PIPELINE TECHNIQUES: Learn to 3D print videogame models
Prepare meshes for 3D printing
This tutorial is designed to help you assess 3D videogame models and adjust aspects of them to make them able to be successfully 3D printable in the various materials offered by shapeways. it may seem obvious to state but things you can make in software cannot always be seamlessly translated into physical objects. computer animations and videogame assets don’t have to take the laws of physics, gravity, material texture and resolution into account.
We will show you a standard workflow for preparing mesh files from videogames as 3D-printable designs. it is worth nothing that there are some software programs being developed with resolution-dependent file formats that use voxels instead of meshes to ensure printability no matter what. however, until those protocols are available in all 3D modelling and CAD software, this tutorial will be your guide to quick file preparation.
We’ll be using Blender to convert our asset to OBJ and Zbrush to edit our asset mesh and make it printable. Then we’ll take advantage of shapeways 3D Tools to help find any remaining problem areas. i will also talk about the different file types needed for printing in full colour versus single-colour materials. if you follow along and still run into printing problems, you can always visit our forums to get advice and tips from our 3D-printing community.
shapeways has partnered with Valve to open their ip to designers who want to print assets from games like the one i’m using from Dota 2.
01 Download and convert game asset Download and convert your selected game asset – i’ve downloaded Bane from Dota 2 and the links to the assets used are on Filesilo. Valve encourages remixing so they provide FBX and Maya file types but we’ll use the FBX to convert to OBJ so that we can take advantage of Zbrush’s sculpting and remeshing. Open Blender and choose import. use rigging markers to repose if desired before selecting and deleting rigging markers. Finally, choose select All By Type > Mesh and export as an OBJ. 02
Settings for exporting at scale import the converted OBJ mesh as a subtool. Go to the Zplugin Menu>3d Print hub and click update size Ratios to select the smaller set of ratios displayed in millimetres. Knowing that we are at correct scale will allow us to identify problem areas in the design. When printing in nylon the thinnest possible edge, or unsupported wall, anywhere on the design is 0.7 millimetres. 03
Geometry tools to make solid hit shift+f to toggle wireframe view on. next turn on edit mode, select the subtool mesh and open Geometry. 3D printers cannot print objects with multiple shells and unmerged meshes so we can use this opportunity to make our design watertight and manifold. in the Geometry menu, select Modify Topology and click Weld Points, then close holes. These tools in combination create a ‘shrink-wrapped’ version of the visible surfaces of the mesh. 04
Remesh and identify work areas now we need to increase our mesh resolution to make the following improvements to the surface smooth. in Geometry, set the Dynamesh resolution to 350 and click Dynamesh. Then go to Zremesher, click Freezeborder and click half under Target Polygons count, and finally click Zremesher. With this step completed we can see that there are areas on the fingers, shoulders and teeth that will need to be thickened and there are still low polygon striations on the surface of the model that we can smooth over. We’ll do all of that in the next step.
Smooth surface and thicken details Once thin areas are identified, we need to selectively thicken just those while avoiding ‘poofing out’ the entire model and losing the sharpness of our overall geometry. We’ll do this by alternating between a smoothing Brush and an inflate Brush. For definitions of what needs to be ‘fixed’, the best resource is the shapeways materials information page. it will be important to adjust your brush size for the smoothing so as to avoid creating non-manifold intersections in tight areas. This part of the process is potentially time-consuming. Keep scale in mind while editing fine detail since some of the very fine details won’t be visible on the final print. 06
Final remesh and export Once the smoothing is satisfactory, Zremesh again to export with good, manifold geometry. Then go to Zplugin and 3D Print hub to adjust the export settings for model size. We’re aiming to make this model about ten centimetres tall so go to the sliders below and set the longest axis, in this case the Z axis, to around 100 millimetres. ensuring accurate scale is the most important factor when preparing a file for 3D printing. 07
Upload and Shapeways 3D Tools if you don’t yet have one, head to Shapeways.com and create an account. click the blue upload button and select your final STL or OBJ file. it will take a few moments for the server to process it. if there are issues with the model, you will have the option to see the details about those problems next to the specific material. click View issues and in this example, the problem areas are as predicted. The pointed fingers and spikes on the shoulders and head could be problematic but they won’t prevent the print from being ordered so we’ll add White nylon to our cart and complete the purchase process.