LEVLIN · FIELD NOTE

Why the Revit model appears twice in 3ds Max after a reload

Published 26 August 2026

The model has not been imported twice. The link failed to recognise geometry it had already placed, so it added it again instead of replacing it. That is an identity failure, and it is the same root cause behind materials resetting and modifiers breaking — showing up in its most visible form.

It is worth being clear about one thing at the start, because it is the part that wastes the most time: the two material options in the reload dialog do not prevent this. They were not built to.

What people actually report

Two accounts, from different users three years apart, describing the same failure. Both had already applied the advice everyone gives.

When reloading the linked model it appears that some of the geometry is duplicated. That causes problems when rendering (blotches) on the duplicated geometry. When reloading I’m ticking the options “keep 3ds Max material parameters / material assignments on reload”. It’s really annoying deleting all of the repeated objects.
When reloading the FBX file the model will appear twice in my scene. … Both issues don’t occur every time. Reloading the FBX file is also hit or miss. I found out if I close Max and reopen, the model will only have one instance.

Three details in those two reports matter more than the complaint itself.

DetailWhat it tells you
The material options were switched onThe documented workaround does not address this failure. It acts on materials, not on matching.
“Hit or miss”, “don’t occur every time”The failure is not deterministic, which is why it is so hard to report and so easy to dismiss.
Closing and reopening 3ds Max changes the resultWhatever the link uses to recognise existing geometry does not survive the session reliably.

Why duplication and material loss are the same problem

Every update to a linked model requires one decision, made per element: is this incoming thing the same thing I already have?

Everything downstream follows from that answer.

If matching succeedsIf matching fails
The existing object is updatedA second object is added — the duplicate
Its material assignment survivesThe new object takes its material from the source
Its modifiers still reference the same indicesNew geometry, new numbering, broken modifiers

So duplication is not a separate bug from the reset materials and the broken UVW. It is the same failure, caught in the act. When the match fails silently you get a reset material. When it fails visibly you get two buildings.

Why it renders badly

Duplicated geometry does not simply sit there. Two coincident surfaces in the same place give the renderer no way to decide which one is in front, and the result is the blotching and flickering the first report describes. On a still it looks like a shading error. In an animation it crawls.

The dangerous part is that the visual symptom points somewhere else entirely. Time gets spent on the renderer, on lighting, on material settings — none of which is the cause.

How to confirm it is duplication

Before changing anything, establish that this is what you have.

CheckWhat you are looking for
Object count before and after the reloadA jump that does not match what changed in Revit
Select one blotchy surface and move itA second, identical surface left behind underneath
Layer contentsTwo sets of the same named objects, or names with a numeric suffix
Scene statisticsPolygon count roughly doubled for the affected part

What the workarounds cost

WorkaroundThe cost
Delete the duplicates by handManual, and it repeats on every reload. On a facade it is an afternoon.
Close and reopen 3ds Max, then reloadReported to help. Not reliable, and it is a ritual rather than a fix.
Unload and relink from scratchWorks, and destroys every material assignment and modifier in the process.
Collapse to Editable Poly to stop the churnEnds the duplication by ending the updates. The model stops arriving at all.

Each of these is a way of surviving the failure. None of them prevents it, and the last two cost more than the problem.

What actually prevents it

Duplication is prevented where the answer to is this the same element? does not depend on guessing. If every element carries an identity that both sides agree on, an update is a lookup rather than an inference, and there is no state in which the update adds a second copy.

That is what Levlin Bridge is built on: elements are matched by identity, so only the ones whose source geometry actually changed are rebuilt. Everything else is left where it is, with its materials, modifiers and UVW still attached — not restored afterwards, but never disturbed.

It is also why the same design removes the neighbouring failures. Materials resetting and modifiers breaking are the quiet version of the failure this page describes loudly.

Frequently asked

Why does my Revit model appear twice in 3ds Max after reloading?

The link did not recognise geometry it had already placed, so it added the incoming geometry instead of replacing it. It is a failure to match elements between the old state and the new one, not a double import.

Do the "keep material parameters / assignments on reload" options prevent duplication?

No. Users reporting duplication had both options switched on. Those options act on materials, not on how the link matches incoming elements to existing objects.

Why is it inconsistent — sometimes it duplicates and sometimes it does not?

Reported behaviour is non-deterministic. One user found that closing and reopening 3ds Max before reloading produced a single instance, which suggests what the link uses to recognise existing geometry does not survive a session reliably.

Why does duplicated geometry cause render blotches?

Two identical surfaces occupy the same position, so the renderer has no basis to decide which is in front. The result is blotching on a still and crawling artefacts in an animation. The visible symptom points at the renderer rather than at the cause.

How do I confirm it is duplication and not a material problem?

Compare object counts before and after the reload, select a blotchy surface and move it to see whether an identical one is left underneath, and check whether polygon count roughly doubled for the affected part.

Is duplication related to materials resetting on reload?

They are the same failure. Every update has to decide whether an incoming element is one it already has. When that decision fails silently you get a reset material; when it fails visibly you get a second copy of the building.


Related field notes

Levlin Bridge

Levlin Bridge is a Windows plug-in that moves geometry between Autodesk Revit and Autodesk 3ds Max in both directions. Push the model from Revit, pull it into 3ds Max, and push the geometry you changed back into Revit as real elements. Only the difference ever moves, so materials, modifiers and UVW stay exactly where you left them. Any Revit 2022–2027 works with any 3ds Max 2024–2027.

Levlin Bridge is in final testing and is not released. There is nothing to download yet. Leave your email and you get the 30-day trial the day it ships.