IFC's fail to upload to Model Server Modified on: Wed, 25 Apr, 2018 at 8:04 AM

The most common problem when IFC files fail to upload is the total size of the IFC files within the model.


In dRofus, a model can consist of multiple IFC files. But there are limits to how many total objects a model can consist of. The total size of the model can be a cause to error messages when you try to upload IFC files to your model. In most cases you will get a error message saying you have reached the model maximum size.


The current version of the Model Server from Jotne EPM Technology that dRous use, operates in a 32 Bits environment. Which means it can hold, at most, 4 billion (4 000 000 000) BIM objects/references. dRofus have access to two different Model Servers; small and big.


To find out if your project use small or big model server please contact support from https://support.drofus.com/en/support/home.


Small Model Server

The small model server can contain 512 models. If we divide the maximum of 4 billion BIM objects on 512 models we get 7 812 500. This is the maximum amount of BIM objects/references each model can contain. We should probably also subtract something for Model Server internal use.


So what does this mean? This mean that it's actually not the model size in bytes that determines whether the model is too big or not. It's how many objects/references all IFC files in the model consist of. However, out of experience we usually advise our users that total model size should not exceed 300 mb when using the small Model Server.


Big Model server

The big model server can contain 128 models. If we divide the maximum of 4 billion BIM objects on 128 models we get 31 250 000. This is the maximum amount of BIM objects/references each model can contain. We should probably also subtract something for Model Server internal use. Out of experience we usually advise our users that total model size should not exceed 1 gb when using the big Model Server.


In conclusion, the 1 gb and 300 mb barrier suggested in this page needs to be seen as a guideline rather that exact limits. E.g. a model on the big model server may be larger than 1 gb if the geometry is not too complex. And the model may fail even if the total model size is down to 700 - 800 mb if the IFC files contains complex geometry.


If your database is set up with using the small Model Server it is possible to switch to using the big if your models exceeds 300 mb. Be aware that existing models uploaded to the small model server will not be moved to the big Model Server.


Suggested solutions to reduce file size

There are several ways to reduce file size of IFC files in BIM projetcs. In this section we will point to two possible ways:


Limit the export in your BIM authoring tool

Most BIM authering tools have functionality for excluding specific objects from the IFC export. One example is Revit's "IFC Options" described in "IFC export from Revit to dRofus" on this page. If you struggle with large IFC files it may be a useful exercise to consider if certain objects can be excluded.


Use third part IFC editing tools to remove objects after export

Other vendors also provides tools for cleaning up and simplify IFC models after export. Useful tools in that regard are e.g. Solibri IFC Optimizer and Simplebim.