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File Size Limitations for Trimble Connect on HoloLens

  • 1.  File Size Limitations for Trimble Connect on HoloLens

    Posted 03-07-2018 19:08

    First off, I love Trimble Connect and the possibilities it will bring moving forward. I am running Trimble Connect on my HoloLens and am in need of some assistance with a few issues I am having... Will there be some how-to guides coming out in the future on optimizing Revit models or Sketchup models to be viewed through the Lens? I have loaded a variety of models to my account and they look and work great from the online browser. When I view on the Lens I feel like anything over 100 MB just simply wont work or is verrrrry laggy/buggy. The smaller models work and operate fine and I feel like there's really not much of a difference between them and the larger ones besides size. If there were a guide with recommended settings, size limits, etc that would be very helpful. I am having my Revit coordinator playing the guess and check game as she continues to try and reduce the size on these and it is getting frustrating for both of us.




  • 2.  Re: File Size Limitations for Trimble Connect on HoloLens

    Posted 03-13-2018 16:13

    Hey Mike,


    Great question! I feel your frustration. Model size and optimization is simultaneously the most important problem and the biggest area of opportunity for us on mixed reality today. In fact, we have a whole team of developers working on increasing these capabilities in our apps.


    We plan to have some better walkthrough guides/videos out for the app in the coming weeks, which will be posted on this community and YouTube. Stay tuned.


    It is, however, difficult to write in stone "what works" and "what doesn't", as it's not as simple as saying "anything less than 100mb will work". The size limitations are more directly tied to polygon/edge counts and densities. For example, you may notice that large models work much better in 1:1 scale than tabletop. This is because the HoloLens is only rendering where you're looking at any given time, so at 1:1 scale you're only rendering a slice of the pie versus the entire model at once. The team at SketchUp recommends tabletop models to stay under 200,000 edges, though you may be able to get away with more in immersive, as you're only taking a "slice of the pie" at a time.


    The same numbers hold for Trimble Connect for HoloLens, too, though the app may be able to handle slightly larger models since SketchUp Viewer is rendering a lot more aesthetics like imagery and textures. Our team is actively working on new ways to load and render models and more properly deal with memory management, so we expect to continue to increase the model size capabilities as the year progresses.


    With all of this said, here are a few best practices / thoughts to keep in mind:


    •  HoloLens is an untethered device, so we have to temper our expectations as to what it can do. Obviously, TC web and desktop are going to be able to render larger models, as they have the processing power of your computer behind them. As we advanced on our software performance, as will the hardware industry continue to push what their next gen devices can do. We're at the very beginning of this tech!
    • Oftentimes when we're using HoloLens we tend to open way more data than we actually need for the use case we're exploring. It will obviously help the device to cut the data area down to whatever it is you're precisely looking at. This is cumbersome, I know, so we're working on adding a few tools to the app that will make this better (layer control, section planes, etc.)
    • Try to scale back specific objects that might be having a more concentrated impact on performance. As an example, I was once visualizing an airport model and it was working great. The next day I came back and it wasn't working anymore. After some digging, I realized that a colleague had pulled a little airplane into the model for aesthetics, not realizing that it was over 1m polygons just by itself. I've seen this with pipe fittings, mesh on desk chairs, high detail on rebar/anchor bolts, etc. Sometimes it's the little (usually curved) things that impact performance the most.


    Hopefully, that gives a bit of help in the interim while we work to build out our documentation further. If you have more questions, feel free to reach out to me at


    Jordan Lawver

    Product Marketing Manager

    Mixed Reality

  • 3.  RE: Re: File Size Limitations for Trimble Connect on HoloLens

    Posted 13 days ago

    Hi Mr. Lawver,

    I'm an XR10 user. I find some models cannot be downloaded and launch on TCH. For example, a 170 MB skp. file.
    But sometimes a small model which file size less than 100 MB still lose details.
    Do you have any standard or suggestion about model size or object numbers compare to file format?

    Application engineer

    Zhong Han Tec. Ltd.

    Scott Chou

  • 4.  RE: Re: File Size Limitations for Trimble Connect on HoloLens

    Posted 8 days ago

    Hello Scott

    When TCH loads a model we analyze the model and automatically optimize/reduce/adjust it to maintain 60 FPS viewing experience and launch the section tool so the user can pare down the model to an area of interest. Our goal is to keep the framerate at 60 fps at all time, so for very large/polygon intensive models you may not see all details as soon as you load the model and this is by design; to keep the framerate at 60 fps. If you are using TCH v 3.0 or later on XR10/Hololen2. We support loading models of any size .

    Model Modes 

    In TCH after you load a Model,  you can work with it in 2 different modes 

    • Table Top (or) Bird's Eye View- In this mode, we prioritize showing larger objects like walls and planes 
    • Immersive @ 1:1 scale (or) Street View - In this mode, we prioritize showing objects closer to and in front of the user than objects that are farther and/or behind the user
    In order to be able to see all details clearly follow the steps below.

    Generic Workflow

    Here is a workflow that will allow you to see most of the objects in the model while keeping the framerate at 60 FPS.  The following steps could be used to visualize most of the objects depending on the model.

    Step 1: Launch the Model

    Step 2: Section the Model. The section tool is automatically launched if the model is classified as needing reduction to keep the frame rate

    • Section Box Tool in Table Top (or) Bird's Eye View
      • In order to display more objects, the section tool could be used to enhance the number of objects rendered.
        • The area of interest could be chosen by using 6 planes and clipping the model. One the box is finalized, the "Enhance" button should be clicked to populate more objects. This can be done as an iterative process.
        • The smaller the section box, more objects get populated in "Bird's eye" mode
        • Note: Though new objects get populated in the section tool, if an object's diagonal length is < 5 cm, then the object will not appear in birds-eye view.
        • Also, you will not see smaller finer details in the section box enhanced view

    Step 3: Go to immersive Mode

    • Selective Rendering - Immersive @ 1:1 (or) Street View
      • There are 2 good ways to get into Immersive from the model viewer. After sectioning the model
        • Street view puts the model at a 1:1 scale. Summon TCH Radial menu with your Palm => Navigate => Street View. Tap a location closer to the object you want to visualize. The small objects(those that were not rendered in birds-eye mode) appear as the user jumps or teleport or walk or turns to a location. 
        • Alignment process puts the model at a 1:1 scale. Summon TCH Radial menu with your Palm => Align => Plane. Follow the instructions on the screen to align your model. All the small objects(those that were not rendered in birds-eye mode) appear as the user  walks or turns to a location
      • In this mode only objects closer to and in front of the user within the budget based selective rendering limit are shown. The objects that are farther and/or behind the user are not shown.
      • As the user turns his/her head to look in another direction the app will refresh the objects in the current view and will continue refreshing as the user walks closer/away or turns the head to a different location
      • In street view(or immersive) mode, all the remaining objects (which did not appear in birds-eye mode will start appearing and these objects are prioritized based on the workflow the user is in.

    Hope this helps. Try out the section tool in your workflow and let us know if you have any questions

    Sree Ceemalapati

  • 5.  RE: Re: File Size Limitations for Trimble Connect on HoloLens

    Posted 7 days ago
    Hi Mr. Sree Ceemalapati,

    Thanks for your reply. As my understanding, there is not a standard recommend like Hololens 1 "200,000 edges". (follow the first reply post)
    I don't understand what "object's diagonal length is < 5 cm" means.
    Can you tell me more about this?
    Thank you so much.


    Application engineer

    Zhong Han Tec. Ltd.

    Scott Chou