Unexpected mm to feet conversion in top level transform

Issue: When we push a model to speckle from Revit, the top level transform seems to adding a conversion to feet.

We recently noticed that when we pushed models to speckle, even though the Revit project units are all in metric units, there seems to be a conversion to feet happening. When we apply the transform when we geolocate the model in our software, we end up with a model that is about 1/3 of the size it should be. As you can see in the transformation matrix I have attached below, there are 3 places with a value of 304.8 which is the conversion from mm to feet.

These are the project units in revit:

image

Here is the project base point:
image

Here is what is being displayed under info → locations

Not sure if this is a bug or if we are just missing something. This seems to be happening for every model we push up.

Appreciate the help!

Hey @kate, welcome back to the speckle community.

Where are you seeing models 1/3 size? Received back in a revit instance or other applications you are taking measurements within?

Are the measurements incorrect if you look at the same commit as a new frontend model version and use the Speckle measure tool?

No matter what units we set in Revit, all objects are internally stored in decimal Feet, so before being worried specifically that matrix scale transformation might be an internal conversion being surfaced. If you could clarify my other questions, we’ll try to resolve your issue.

Hi Jonathon,

We are seeing them 1/3 of the size in our software tool that geospatially positions the models. Our software takes that top level transform and applies it to move the whole model to the survey point.

Using one of our test models, the measurements in speckle look fine.

And the coordinates of elements are correct as well (shown in mm). I have added some measurements in revit to show the distance from the internal origin which match up with the base line x and y.


The only place I can see that conversion to feet is in the top level transform. Also, I couldn’t see where to find the top level transform in the new UI. Is it no longer able to be seen?