VIDEO TUTORIAL: How to compress / reduce the size of an industrial 3D CAD model with MeshLab and Blender?

Wednesday 22nd of June 2022 03:09:28 PM |

We previously published a tutorial on reducing the size of any 3D model with Blender, a method suitable for most 3D models including animated ones. But for some static CAD models that have very high definition, there is a way to get a better result for your final AR render.

This method supports the following 3D CAD file formats: STL, OBJ, STP, IGS, OFF, GLTF, GLB, WRL, BREP, XBF, PLY, MSH, PNG, LOG, ES, 3DS, QOBJ, PTX, VMI, PTS, APTS, XYZ, PDB, TRI, ASC, TXT, X3D, X3DV, FBX, BRE, DAE and E57.

What is an industrial 3D CAD model?

CAD stands for Computer Aided Design, it is mainly used to name the 3D modeling done for parts and assemblies in industry.

Because they need high definition to enter production, they are modeled on dedicated 3D CAD software such as: Fusion 360 Autodesk , Solidworks, CorelCAD, AutoCAD, Tinkercad, FreeCAD, SketchUp, Solid Edge, Bentley, LibreCAD, SOLVESPACE, BRL-CAD, QCAD, IRONCAD, PTC, CATIA, OpenSCAD, Rhino and Siemens NX.

The file formats used are also dedicated.

Reduce the size of an industrial 3D model

By using the method below, you can get a lighter CAD 3D model for augmented reality display via an AR Code.

As a first step, if you have access to the software used to design your model, you can reduce its number of vertices directly in it. If you can't have access to the software and to go further please refer to the method below with CAD Assistant, Meshlab, Blender and Gimp:

1 - STP (STEP), IGS (IGES), LOG, OFF, 3DM, VRML, WRL, MSH, XBF, BREP files: Convert your 3D model with CAD Assistant (NON-animated model only)

CAD Assistant software is a free 3D CAD converter for personal and commercial use. You can download it here : https://www.opencascade.com/products/cad-assistant/

cad assistant

Import your 3D model into the interface, then export it in .OBJ format. This simple conversion step will prepare your 3D model for the next step.

2 - Decimate your 3D model with MeshLab and/or Blender

Decimating a 3D model will reduce its number of vertices, this will result in a lower definition especially on the curved parts of your model. If the decimation is too high, some vertices may lose their texture information, making the model look like it has a hole. To avoid this, it is important to keep checking the rendering of the model after each decimation.

For the best result, we advise you to use both software: MeshLab and Blender. Blender can produce the best result for most 3D models. MeshLab will only be used for very high definition static models that are seeing decimating issues on Blender.

Decimation with Blender: (https://www.blender.org/download/)

Import your 3d file (GLB, GLTF, DAE, ABC, USD, BVH, PLY, STL, FBX and X3D only)
Select the first mesh to decimate
Do the decimation as below, try to define each mesh under 40,000 faces. If decimation create UVs holes in your model, we recommend you to do a Meshlab decimation first. Its decimation algorithm differs from that of Blender, the result may be better.

decimate blender

Export your model in *.glb format by selecting "Apply modifiers" but not the "Compress" option.

apply modifiers blender

Decimation with Meshlab: (https://www.meshlab.net/#download)

Import your 3d file (ES, 3DS, PLY, STL, OBJ, OFF, QOBJ, PTX, VMI, PTS, APTS, E57, GLTF, GLB, XYZ, PDB, TRI, ASC, TXT, X3D, X3DV, FBX, WRL, BRE, DAE and E57)

Then depending on whether it is textured or not, select:

Textured: Filters > Remeshing, Simplification and Reconstruction > Simplification: Quadric Edge Collage Decimation (with texture)
Not textured: Filters > Remeshing, Simplification, and Reconstruction > Simplification: Quadric Edge Collage Decimation

decimate Meshlab

Set a number of faces that will preserve the quality of your model.

simplify meshlab

Export your 3D model in *.obj format to include any textures.

export meshlab

3 - Compress textures with Gimp

This step is only necessary if your model has image textures.

Import your 3D model into Blender
Export your 3D model in .gltf + .bin + textures
Open texture files in GIMP
Scale images (to 1024X1024 or less if higher compression is needed)

gimp scale

Export textures in *.jpg format with a resolution of 90 (or less if higher compression needed)

gimp compress

Edit your .gltf file with a text editor by replacing the texture formats if needed (here ".png" to ".jpg")
Save it

4 - Convert your model to .GLB for an upload on AR Code

To convert your model and export it:

Import your model into Blender
If you have already decimated your model with Meshlab, you can try adding a Blender decimation as detailed in the 2nd step.
Export your model in *.glb format, select "Apply modifiers" but not the "Compress" option.

apply modifiers blender

You can now easily upload your 3D model to the AR Code platform.