Lighten an IFC model and download its light version

Introduction

A heavy IFC model is slow to transfer and to open. In organizations where the feature is enabled, SeveUp App produces a lossless light version of it, to download for viewing or exchange. The original file is never changed and remains the reference.

This article explains what lightening actually does to the file, when it runs, where to find and download the result, which messages you may see when no light version is offered, and how each optimization counts toward the monthly volume of your plan.

Prerequisites and limits

• An imported model whose file weighs more than 50 MB. Below that, no light version is computed.
• An organization where lightening is enabled: it is opened organization by organization and is not available on every account yet.
• A plan that includes model optimizations: the trial includes none.
• You do not start anything yourself: the computation starts on its own, in the background, after import. It delays neither conversion nor the 3D.

Light version of the IFC

Lightening rewrites the file without losing anything:

• entities without an IFC identifier (GlobalId) that are strictly identical are merged: points, directions, axis placements, loops, faces, shells, lines, colors, styles, units;
• entities left orphaned are removed;
• identical geometric shapes are shared instead of being repeated.

No object carrying a GlobalId is ever merged or removed, and the file's line identifiers are kept. No coordinate is rounded.

A check then compares the result with the original: objects, data, schema and geometry, object by object. The light version is kept only if this proof succeeds and the file is at least 30 % lighter. Otherwise, nothing is offered.

Where to find the light version

1. Open the model from the "Models" page.
2. Open the "Revisions" tab.
3. In a revision's row, find the feather-shaped icon, between "Retrigger" and "Download".

The icon has no visible text: its label sits in the tooltip, and screen readers read the same text. Hover over the icon to see its state:

• active: "Download the light version: X MB → Y MB, proven identical to the original (objects, data, geometry). For viewing and exchange; the original remains the reference.";
• in progress: a spinning icon and "The light version of this model is being computed (a few minutes up to an hour for very large models).";
• greyed out: the reason it is missing shows on hover.

While the computation runs, and during the two hours after import, the state updates on its own: the icon becomes active as soon as the light version is ready.

Download the light file

Click the active icon: the download of the light file, in .ifc format, starts. The tooltip already shows both sizes, before and after the lightening.

This file is for viewing and exchange. Do not reopen it to edit it in a tool that modifies entities: a shared entity that changes modifies every object that uses it. For any modification, start again from the original, which the "Download" button on the same row always provides.

Optimization quota

Each optimization started counts toward your plan's monthly "Model optimisations" quota, whether the light version is kept or not.

On plans that include some, the "Model optimisations" gauge appears under "Your usage this month", on your account's "Usage" page.

What can go wrong

• "No light version: model under 50 MB, already light." The file is below the threshold.
• "No light version: the possible gain was under 30 %, the original is already compact." The original is kept as is.
• "No light version: the check could not prove it identical to the original, so it was discarded." As a precaution, no unproven file is delivered.
• "No light version for this model." The computation did not run: it only happens after import, in organizations where it is enabled.
• "Light version temporarily unavailable. Please try again later." Reading the state failed; try again a little later.

FAQ

Does the light version replace my original file?

No. The original is never changed and can still be downloaded. The light version is a separate file, for viewing and exchange.

Is lightening available on my account?

Not necessarily: it is opened organization by organization. If a model over 50 MB shows "No light version for this model.", it is probably not enabled for your organization. Write to us from the Contact page to talk about it.

Can I start lightening by hand?

No. It starts automatically after a model over 50 MB is imported, in organizations where it is enabled.

Does an optimization that is not kept count toward the quota?

Yes. The quota counts the optimizations started in the month, whether the light version is kept or discarded.