In the workflow of sketching models in SketchUp and rendering in 3ds Max, we typically use the File > Import command to bring SketchUp models into 3ds Max as Editable Meshes. When modifications are made in SketchUp, we separate the edited parts and re-import them into 3ds Max.
Although this process can be expedited with tools like Paste from SketchUp, this method has a downside: when re-importing, you have to reapply any modifiers and materials you had set up on the previous model. Again, there are tools to address this issue, but it remains somewhat inconvenient to continuously update the setup.
In this guide, I will introduce you to a different approach. Instead of importing SketchUp models, we will link them into 3ds Max. With just one click, you can update the model in 3ds Max, and the scene will be ready to render immediately. Let’s get started.
Prepare
In reality, 3ds Max does not support direct linking of SketchUp (SKP) files. The formats it does support include DWG, DXF, RVT, and FBX. Therefore, we will need a support tool called SketchUp Linker. This is a free tool that I developed, which links SketchUp files into 3ds Max through an intermediary FBX file.
Watch the introductory video about the script below.
Installing SketchUp Linker
After downloading the installation file, extract it to obtain the MZP file. Drag and drop this MZP file into the 3ds Max viewport. Click Install to complete the installation. Once installed, the SketchUp Linker dialog will automatically appear, and you can start using it right away.
For easier access, you might want to add the SketchUp Linker button to your 3ds Max toolbar. Go to Customize User Interface > Toolbars. In the Main UI group, select the Category labeled D95 DESIGN. Then locate the SketchUp Linker command, and drag it onto your toolbar.
The script has some options in the Script System Settings. However, the default settings should work well for most situations. If you want to learn more about these settings, you can go to Script System Settings and hover over each checkbox to read the tooltip about it.
Preparing the SketchUp File
Just as when you traditionally import, you should clean up and optimize the SketchUp file before starting the transfer to 3ds Max.
To ensure smooth linking, before start, first import into 3ds Max the elements that do not change. Then, delete these from the current SketchUp file, leaving only what frequently changes. This will significantly reduce the reload time. Note that the script will not load hidden objects in the SketchUp file, so instead of deleting them, you might prefer to hide them using layers (tags) in SketchUp.
The script supports linking multiple files at once. Therefore, for larger projects, you can split them into different files to speed up the reload process.
When linking or reloading a file, the SketchUp Linker will detach all faces, then reattach them grouped by material. Thus, applying and naming materials correctly in SketchUp is crucial. If you have experience with Lumion, this process will seem quite familiar.
Starting the Link
Once everything is ready, we can begin the linking process. Open SketchUp Linker in 3ds Max, then click the Attach button. A file selection window will appear. Select the SketchUp file you want to link and click OK. For typical architectural and interior models, processing will take about 5-20 seconds. The more detailed and material-heavy the model, the longer it will take.
After the linking is completed, the script will display a “Attach completed!” notification on the screen, along with the processing time. At this point, if everything works correctly, your SketchUp model will appear in the 3ds Max viewport, and you can start working on it.
An FBX file will be created in the directory containing the SketchUp file. It is safe to delete this file, and it will not cause any issues for the script. However, it’s best to keep it to avoid annoying “missing file” notifications when reopening 3ds Max.
Working with the Linked Model
You will find the linked model in the form of an Editable Mesh, with no properties in the Modify tab except for the Reset Position button in the Linked Geometry group. These models cannot be edited directly or converted to Editable Poly or Editable Mesh.
To edit them, you would need to add an Edit_Mesh or Edit_Poly modifier. However, this is not recommended because any geometric modifications may be lost if vertex or face information changes when the model is reloaded.
Other modifiers such as Smooth, UVW Map, Chamfer, or Symmetry can be added to the model. Along with the applied materials, these modifiers will be preserved when you reload the SketchUp model. This is very convenient when you need to continuously edit the plan.
Managing Linked Models
Once models are linked, the SketchUp Linker script displays a list of linked files in its main interface, allowing you to effectively manage these connections. This list is organized into three columns:
- File Name (1): displays the SketchUp file name currently linked in the current scene.
- Linked Status (2): if the link status is “Loaded”, the model has been linked into 3ds Max. Reloading will not cause the loss of applied materials and modifiers. If for some reason this link breaks (for example, a conflict with other scripts), the script will display a “?”. At this point, reloading will not preserve the applied materials and modifiers. This error is almost impossible to fix.
- File Status (3): when starting, the script will check the path of SketchUp files on the hard drive. If the SketchUp file can be found, the script will display “Found”. Otherwise, it will display as “Missing”, and you will not be able to reload these models. To fix it, use the Relink feature to redirect the path to the folder containing the SketchUp file. Or if the file name has changed, right click, select Change SketchUp File to replace the SketchUp file.
Right-clicking a file in the list offers three options:
- Edit Model: Opens the file in SketchUp for modifications.
- Change SketchUp File: Replace the existing SketchUp file with another.
- Open Containing Folder: Opens the folder where the SketchUp file is stored.
Reload Model
To update a linked model, select one or more files from the list, and then click the ‘Reload’ button. For batch updates, right-click the Reload button to refresh all models in the list. Similar to attaching files, a notification will appear once the process completes.
Important reminder: always save your current 3ds Max file before performing a reload to ensure no progress is lost.
Relink Model
During work, you may move the SketchUp file to a different directory, causing the script to indicate “Missing” in the File Status column. To update the path for the model, select one or more linked files from the list (1), then press the Relink button (2). Choose the new folder for the SketchUp file and click OK. The paths will be updated.
Note that this feature differs from Change SketchUp File in the right-click menu. For example:
- Relink is used for multiple files at once, while Change SketchUp File can only be used for a single selected file.
- If you change the path but not the file name, for instance, from “D:\PROJECT\THT_3.skp” to “E:\CONSTRUCTION\THT_3.skp”, use Relink.
- If you rename the SketchUp file, regardless of whether the path changes, for example, from “THT_4.skp” to “THT_5.skp”, use Change SketchUp File.
After successful relinking, the script will display “Found” in the File Status column. You can then reload the model as usual.
Unlinking Files
When you want to unlink files in the current scene, there are two options: Detach (1) and Bind (2).
- Detach: Removes the link and deletes all linked objects in the scene.
- Bind: Removes the link but keeps all linked objects in the scene, converting them to Editable Mesh. At this point, objects will be fully imported into 3ds Max, and you can edit their geometry without adding Edit_Poly or Edit_Mesh modifiers.
Note that unlinking cannot be undone. Upon undoing, your model will return to its previous state, but the link in the script will be permanently lost. Therefore, use this feature with caution.
Conclusion
This guide is written for SketchUp Linker version 1.00. Subsequent versions may have some changes, but the core functionality will remain the same. You can track these changes in the Change Log section on the product’s homepage.
No new process can be perfect right away. The script still has some limitations, and I acknowledge that. Like Paste from SketchUp, before it can work smoothly and reliably, it will need some time for optimization.
During that time, user feedback is crucial for the script’s development. So, don’t hesitate to reach out and share your experience with the script, as well as any suggestions for improvement. Wish you success!