Exporting to VRML and X3D for color printing

Exporting to VRML and X3D for color printing

Introduction :

With the arrival of the “Full Color Sandstone” material, Shapeways now supports color information in your models. There are two ways to apply color: as a 'per face' material, or as a UV texture map.

'Per face' materials are easier to work with, but will give you less detail. UV texture maps can be very detailed, but require the careful mapping of the texture map to your object.

To use 'per face' materials, simply apply material colors in your 3D application and export to VRML2. Then, jump to step 4 below to read how to upload your model.

The use of texture maps requires some additional steps. This remainder of this tutorial explains them: designing, exporting, creating an archive and uploading. To see the 3D printing process and some printed examples in all their awesomeness, check out our video.

Process outline:

Uploading a file with texture maps requires a few steps. I'll outline them first, and then go into detail for each one of them:

In your 3D application, create a texture map.

Export your model to VRML97 or X3D.

Create a .zip archive of the exported model, and all the texture map images.

Upload the archive.

Step 1: Creating a Texture map :

Create a UV texture map in your 3D application. As this is wildly different for each application, I won't go into details here. I'll just list the restrictions that you have to keep in mind:

Shapeways only supports UV textures, no other texture projections.

You can only use bitmap textures (no 'procedural' shaders').

Texture files must be in JPG or PNG format.

You can use more than one texture map on your object, but the maps are not allowed to overlap – the printer cannot figure out which texture to print in that case.

The last limitation is the resolution of your texture – we recommend you keep the total resolution of your texture maps below 2048x2048 pixels. For example, if you need 4 textures, keep them all below 1024x1024 pixels.

Step 2: Export your model to VRML97 or X3D

Most applications support VRML97 (also called VRML 2.0). Some may already support the successor to VRML: X3D. You can use both, but please make sure you don't export to VRML 1.0! For both file formats, one unit equals one meter. Your software may support other units and in that case, Shapeways will use these.

Step 3: Create a .zip archive of the exported model, and all required texture maps

You now need to pack the VRML or X3D file and the texture maps into one .zip file. Take care that the ZIP file only contains the files, and no folders!

Step 3: Create a .zip archive of the exported model, and all required texture maps

Step 4: Upload the model

Uploading the zipped archive is identical to a regular model upload.

That's it! You have now uploaded a fully textured color model

Common problems

Q: The textures don't display, or I get an 'xxx' error.

A: A number of problems can cause this:

The images aren't included in the uploaded archive.

The images ARE included in the archive, but you zipped a folder instead of the individual files (see above).

You DID include the textures correctly, but the filenames are subtly different from the definition in the VRML97 or X3D file: Windows is 'case insensitive' which means that it treats 'mymap.jpg' and 'MyMap.jpg' as the same files. Our servers aren't as forgiving though – they require the file names to match exactly.In order to check this, open the VRML97 or X3D file in a text editor and search for your texture file name. See if they match.

Q: Shapeways is telling me that my object is too big!

A: Remember that VRML97 and X3D expect your object to be measures in meters. So, if you want to create something that's 10mm long, you'll have to model it as 0.01m. Some 3D packages will allow you to select a scale during export. If not, you'll have to manually scale your model down by a factor of 1000.


Q: I get a 'non-manifold' error after uploading, but I'm SURE that my model is correctly manifold.

A: VRML97 and X3D use a standard unit of 1 meter. For very small details, this can cause problems with the internal accuracy of the calculations of our software: small details can get welded together. In turn, this often creates non-manifold errors. We are looking in to this.

Ensure more than enough structural strength of legs (thus holding a bigger body volume – limp thickness ratio)