Importing Models
Import GLB and GLTF 3D models into your simulation scene
Importing Models
Sim Assist supports importing 3D models in GLB and GLTF formats. You can bring in models from CAD software, 3D modeling tools, or the Marketplace to build your simulation scenes.
Supported Formats
| Format | Extension | Description |
|---|---|---|
| GLB | .glb | Binary glTF — single file containing geometry, textures, and animations. This is the recommended format. |
| GLTF | .gltf | JSON-based glTF — references external .bin and texture files. Upload as a .zip archive containing all referenced files. |
Both formats support PBR (physically based rendering) materials, skeletal animations, morph targets, and multiple meshes. Sim Assist does not support .fbx, .obj, or .step files directly — convert them to GLB first using a tool like Blender or an online converter.
Import Flow
There are two ways to import a model:
Drag and Drop
Drag a .glb file from your file explorer directly onto the 3D viewport. The model appears at the world origin (0, 0, 0) and is added to the Component Tree.
File Picker
- Click the Import button in the toolbar or the Assets panel.
- Select a
.glbor.gltffile from your computer. - The model is placed at the world origin and selected for immediate positioning.
After import, use the Move (G), Rotate (R), and Scale (S) tools to place the model in your scene.
Optimization Tips
Simulation performance depends on scene complexity. Follow these guidelines to keep your scenes running smoothly:
Polygon Count
Aim for under 100,000 triangles per model and under 500,000 triangles total in a scene. Use decimation or Level of Detail (LOD) in your 3D modeling tool before export. Mechanical parts from CAD software often have excessive geometry — simplify curved surfaces where visual fidelity is not critical.
Textures
- Use textures no larger than 2048x2048 pixels. For small parts, 512x512 is sufficient.
- Prefer JPEG compression for color textures and PNG for normal maps and masks.
- GLB files embed textures — compress them before export to reduce file size.
Naming Conventions
Name your meshes and objects descriptively before export. The names carry over into the Component Tree. A model with parts named Mesh.001, Mesh.002, Mesh.003 is much harder to work with than one named ConveyorFrame, ConveyorBelt, ConveyorMotor.
Use a consistent prefix for related parts: Conveyor_Frame, Conveyor_Belt, Conveyor_Motor. This keeps the Component Tree organized and makes I/O binding easier.
Materials
Keep the number of unique materials low. Each unique material can result in a separate draw call. Combine materials where possible, and use texture atlases for parts that share similar surface properties.
How Imported Models Appear in the Component Tree
When you import a model, Sim Assist preserves the hierarchy from the source file. A GLB file with nested objects creates a matching tree structure:
- Root node — The top-level object, named after the file (e.g.,
ConveyorAssembly).- Child nodes — Each object or mesh group in the source file becomes a child node.
- Mesh nodes — Individual meshes within groups.
- Child nodes — Each object or mesh group in the source file becomes a child node.
You can rearrange this hierarchy freely in the Component Tree after import. Rename nodes, re-parent components, and delete parts you do not need.
Each imported mesh node can have physics colliders and I/O pins assigned to it. For example, you might assign a proximity sensor I/O pin to a specific part of a machine, or add a rigid body collider to a moving component. See Component Tree and Physics Engine for details.