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V5 - Revit Plugin - How does LOD setting work?
V5 - Revit Plugin - How does LOD setting work?

Discover what LOD options you have and how they affect the overall model performance in 3D Repo

Written by Faisal Ramady
Updated over a week ago

The ability to bridge the gap between design authoring tools and the target audience using a web browser is relatively new. We are making it a reality, and whilst it's revolutionary, model performance in the web browser is critical in its success. The good news, we have an easy solution to a common problem.

What is it and How does it work?

We can improve your model performance on the web, by optimising geometry before uploading it to 3D Repo. The main benefit of this is to reduce the amount of memory required for your browser tab to render 3D Models.

Currently, this option is available for our Revit Plugins only. It works similarly to selecting a LOD when exporting IFC or NWC files from Revit. Users can define how detailed the model geometry will be in 3D Repo, and there are six options to choose from: Very Low, Low, Medium, High (default), Very High and Maximum. In most cases, the LOD definition will affect intricate or highly detailed geometries. There will be little or no effect on meshes/geometries such as flat walls, slabs or roofs.

Worked Example

Let's take a look at how it works in practice. We'll be looking at one particular area of a large MEP model highlighted below. Our sample data will consist of:

  • Round / Curved pipes

  • Highly detailed pipe junctions

  • 2000+ objects

  • 41 MB file size (Revit 2020)

LOD export results

  • Maximum LOD will represent model geometry as intended. Anything below that threshold will present us with geometry optimisation results.

  • Browser Tab Memory the amount of RAM memory required to run 3D Models

Level of Detail

Export File Size (MB)

Compression (MB)

Compression (%)

Browser Tab Memory (MB)






Very High





High (Default)















Very Low





As evident in the export results table, any decrease in the Leve of Detail from its original state (maximum), results in drastically reduced file size. We are experiencing high percentage compression rates, but most importantly, an overwhelming reduction in the Browser Tab Memory allocation.

With the default LOD (High) we can review models in 3D Repo with only 35% Browser Tab Memory allocation (compared to Maximum LOD). On top of that, the geometric optimisation is barely noticeable in the model viewer. For a more visual understanding of the results, review the graphs below.

Export File Size vs Browser Tab Memory use

Compression rates for LOD options

Geometry Optimisation Results

Whilst numbers and graphs tell us the story of how well the geometric optimisation performs, the real question is how does the geometry look at the end. Below is an example of how a geometrically intricate part of the model looks like in 3D Repo for each of the LOD options. Note that Maximum represents geometry as intended.

Using the 3D Diff feature in 3D Repo, we can analyse geometric changes between each LOD option. We will use the Maximum LOD as a base model and measure it against each LOD option to understand how much and where the geometry differs.

  • Very Low large amounts of difference but mainly to curved/round objects (not flat/square meshes as seen in the background)

  • Low a sufficient amount of difference to curved/round model objects

  • Medium some changes to curved/round objects, but mainly to intricate junctions

  • High (Default) minor geometric changes, mainly to intricate junctions

  • Very High almost no geometric change visible

  • Maximum no geometric changes to the original model

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