Issue with Missing Holes in Converted GLB File Using HOOPS Exchange SDK

I hope this email finds you well. I am writing to bring to your attention an issue that our team has been facing while using the HOOPS Exchange SDK. We have been working with IFC files for steel bars with bolts’ holes, and when we convert these files to GLB format using the HOOPS Exchange SDK, we have noticed that some of the holes are missing in the resulting GLB file.

This issue is causing significant disruptions in our workflow as the accuracy and completeness of the converted files are essential for our project. We rely on the capabilities of the HOOPS Exchange SDK to ensure that our engineering designs are accurately represented in various formats for downstream use.

To provide you with more context, we are using the following environment:

  • HOOPS Exchange SDK version: [Please specify the version you are using]

  • Operating System: Linux (AKSUbuntu-2204gen2containerd-202307.04.0)

  • Programming Language: c#

During our investigation, we observed that the missing holes in the converted GLB file seem to be related to some sort of threshold on the vertices. We are just assuming here!. It appears that there may be a condition that causes the holes to be considered as blocked (welded) or not transferred completely during the conversion process.

We kindly request your assistance in clarifying whether such a threshold or condition exists within the HOOPS Exchange SDK that could lead to the omission of certain vertices or holes in the resulting GLB file. If this is the case, we would greatly appreciate detailed information on how to adjust or disable this threshold to ensure that all holes in the original IFC file are accurately represented in the converted GLB file.

If additional information or files are required from our end to help diagnose and resolve this issue, please let us know, and we will be more than happy to provide them.

We understand the importance of timely and accurate support in our development process, and we greatly appreciate your attention to this matter. We look forward to your prompt response and a solution that ensures the correct conversion of IFC files containing steel bars with holes into GLB format.

Thank you for your understanding and cooperation.


Hey there @khaled.elammari,

Can you verify what the model looks like when imported into the HOOPS Demo Viewer? If the holes are missing in the viewer, then it’s most likely an import issue on the FC side. If not then more likely the GLTF export part.

I could see the holes on IFC viewers (e.g., BIMvision or Open IFC Viewer) , but I couldn’t see some of them when using the the HOOPS demo viewer. This apply on the original IFC and the converted glb file.

I’m attaching the following screenshots to compare:
Original IFC using OpenIFCViewer:
Original IFC using HOOPS:
Converted GLB using HOOPS:

Thank you

Thanks for the screenshots! Can you provide the file you’re trying to convert? I think that might helps us better figure out what’s going on. If you don’t feel comfortable posting it here, feel free to message me directly either through the forum or at my email

just sent you an email. Thanks