Importing a BIM/CAD file and preparing it for 3ds Max

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This workflow uses the following SiNi plugins - IgNite. Scribe, Sculpt, Jumble, Forensic.

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The below methodology is based on many years of daily importing of Revit, Sketchup, and AutoCAD files. Traditionally, it's always been a manual process that takes time to prepare for working in 3ds Max. The workflow becomes frustrating when your client continues to send you updates to design, thinking you can simply open the file and like magic, everything is updated - ignoring the fact you have spent considerable time fixing geometry and UV texturing geometry. Anyone familiar with this iteration practice will understand the reference to the film Groundhog Day! Many of the IgNite plugins were designed to ease this process and fast-track tasks - allow you to stay sane (and not want to kill your clients). You may wonder why you simply don't file link the file to allow you to update when there is a new Revit or AutoCAD file available. This workflow is fine if you work on simple renders and don't wish to modify the geometry, adding details. Many professional artists prefer to import the geometry and either remodel everything, or parts of it. This is the workflow SiNi supports and that we will discuss below.

Who should use this workflow and why?

Anyone who works with architectural models, engineering and product models, and any computer-aided design files where a 3D model has been made will benefit from this workflow. Ask yourself the following and if any of these apply to you, our plugins will improve your current way of working.

  • Do the BIM/CAD files you receive include layers or is everything imported on the default layer?
  • Are the BIM/CAD files optimised? Or have they simply been exported with everything included?
  • How long does it take you to prepare a model? Do you budget for BIM/CAD prep time?
  • If requested by your client, can you afford to re-import and reproduce the prep-work?

If you agreed with any of the above, we can help! Having extensive experience in this, we can clean up and prepare an average multi-story apartment building in 10-30 minutes, depending on its design complexity.

Live demo slashes 3 days work to 20 minutes!

This was proven in a customer meeting. The archviz studio team were discussing how they had taken 2-3 days to clean up a difficult skyscraper model. We asked if we could take a look at it and within 20 minutes, we had cleaned it up!

Let's show you how.

01. Import BIM/CAD models

Import the file into 3ds Max. When it completes importing the very first thing you should do is inspect it using Forensic.

Forensic Forensic (UI) - Scene Info

Screenshot of Forensic checking file on opening it.
Screenshot of Forensic checking file on opening it.

Inspect with Forensic and tidy up the project before getting started. Make sure you first delete the CAD blocks! We will ignore the materials for now as we want to use their information to make layers.

Work with Layers

IgNite (Springboard) IgNite (UI) - Standard Does your 3D scene have layers? YES/NO? If no, we recommend using the make Layers by Materials.

Screenshot of IgNite - Layers by Material.
Screenshot of IgNite - Layers by Material.

This will automatically create layers based on the imported models assigned materials. Everything with the same material will be moved to the corresponding layer.

Once complete, check the layers and on the Default and Generic layers review the content.

Screenshot of new layers.
Screenshot of new layers.

If there are a lot of objects, consider using the Layer by Object tool to create new layers.

Remove Clutter

Inspect the model and remove unnecessary objects. If, for example, you are working on an exterior building model, why keep the interior details such as door handles and CAD blocks of furniture?

IgNite - Select Similar tool

Screenshot of IgNite - Similar Objects.
Screenshot of IgNite - Similar Objects.

Use this to select items and all replicas. This works even if the imported 3D model has no instances.

Screenshot showing internal doors selected with one click.
Screenshot showing internal doors selected with one click.

Jumble - Select by Volume tool Although rare, you may find the client has sent you a file that includes tiny geometry - such as screws and ironmongery. By adjusting the volume size you can quickly isolate these unwanted objects and delete them. Jumble (UI)

02. Optimise workflow

3ds Max works best with fewer objects in the viewport. By collapsing models to single edit-mesh (or poly), 3ds Max performs much faster. The following steps show you how to quickly attach, scan and fix 3D assets and if necessary explode to separate objects again.

Sculpt Sculpt (UI)

Attach by layer - select layers to attach. (turn off weld - we'll do that later).

Screenshot of Sculpt - Attach by Layers.
Screenshot of Sculpt - Attach by Layers.
Screenshot of attched objects in layers.
Screenshot of attched objects in layers.

Tip - Geometry instances

If you plan to work on the model and wish to keep the replicated geometry - such as windows or balconies. Don't collapse them just yet. Exclude those layers and check out the Proxy workflow suggestion.

Check and fix tools

Detach and Delete Double Faces

It is a good idea to check if the model has double faces. We've not found an imported file that doesn't have them. Why does it matter? Coplanar faces can cause issues down the line, especially if you're creating an animation.

Screenshot of Sculpt - Detach Double Faces.
Screenshot of Sculpt - Detach Double Faces.

Weld Vertices

The In-progress status bar allows you to review the before/after statistics before applying. You can the selected objects vertices will be reduced by approximately 50% when I apply the Weld.

Screenshot of Sculpt - Weld Vertices.
Screenshot of Sculpt - Weld Vertices.

Clear Smoothing Groups

Screenshot of Sculpt - Clear Smoothing Groups.
Screenshot of Sculpt - Clear Smoothing Groups.

Click on Clear Smoothing Groups.

Have you imported Sketchup models?

Is there messy geometry?

  • Planes - try using the retopology plane to create a new surface.
  • Block models - try using retopology massing to create new block geometry.

Please see Sculpt (UI) for more info.

Screenshot of Sculpt Retopology tools.
Screenshot of Sculpt Retopology tools.

Tip - Retopology tools

These are designed for simple geometry, not to select a detailed building and expect it to remake it for you! For more information check out the information on the Sculpt UI page.

Imported 2D Data?

Scribe Scribe (UI) Have you imported 2D CAD splines as well as 3D geometry?

Use Scribe to work on imported splines and shapes, cleaning them up in a similar way to the above.

Forensic

Open Forensic and scan the scene. Remove the empty layers.

Screenshot of Forensic - remove empty layers.
Screenshot of Forensic - remove empty layers.

03. Clean up for production

We now may want to tidy up the further.

Simplify layers

Move collapsed objects to a new layer with objects by material only.

Screenshot of new layer with attached objects.
Screenshot of new layer with attached objects.

You may want to split the model into workable objects - each building for example.

Screenshot showing splitting the 3D model into seperate buildings.
Screenshot showing splitting the 3D model into seperate buildings.
Screenshot showing seperate building on new layers.
Screenshot showing seperate building on new layers.

Reset Pivot points

Screenshot showing resetting pivot point.
Screenshot showing resetting pivot point.

If you split the model, remember to reset the pivot using IgNite.

Explode Objects

Screenshot showing Sculpt - Explode by Material.
Screenshot showing Sculpt - Explode by Material.

If you want to split the models by Material use the Sculpt - Explode Objects tools. In this case, we used Explode by Material. This creates generic objects named after the layer.

Roadmap - Explode Objects

You can see from the above when we explode by material we loose the reference to the materials. You need to rename these manually - which is not right! We plan to update this to keep the material names and append them as a suffix to the objects.

Reset Wire Colour

Screenshot of IgNite - Random Wire Colour.
Screenshot of IgNite - Random Wire Colour.

If you want to reset the wire colours, use the IgNite tool.

Conclusion

Screenshot of final project rendered in V-Ray 5.
Screenshot of final project rendered in V-Ray 5.

This is a fast process that once you get used to it, allows you to prepare imported models quickly. This means it's less of a burden when you need to do it again...and again!

Roadmap - Wishlist!

The SiNi team have discussed the idea of adding an IgNite History Recorder (similar to Photoshop's History/Script Events). This might allow our users the ability to save their prep work (above) and reapply it to an updated model, shortening the iterative process. This might also include more advanced actions such as texturing etc.

Why would I use this workflow and not MAXScripts?

  • Multi-threading - these tools use multi-threading to process heavy tasks. If you don't have hours to kill waiting for MAXScripts (if they don't crash) then it's the only via option.

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