Topic: [Awaiting reply] Handling a large number of buildings

[Dragooon]

Hello! I am trying out Lumion and I have a Group Housing project with a large number of same buildings. I have 4 types of buildings and about 15 instances of each on my final plan. I am modelling using Revit, and I am concerned about how Lumion would handle such a project. If I just export my final plan from Revit, it just takes forever which makes updating and working on the model a huge pain. So far the best idea I have so far is:

1. Export each building to Lumion individually
2. Export the site plan without the buildings
3. Re-assemble the site within Lumion.

I am guessing this would allow me to iterate my model much faster. Is there a better way to go about this? Also, a lot of my buildings would have similar object (planting, lighting, etc.) placement. Is there a way to quickly handle those without copying/pasting each of them endlessly?

[Morten]

Welcome, Dragoon.

You're tackling this problem from the right angle - kudos for thinking ahead.

Exporting the 4 building types as separate DAE files and then only having to re-import the model that has changed (by isolating the model in a 3D View in Revit prior to exporting it again) is indeed the recommended way for scenes that take a long time to export.

If it takes ages to export the whole scene in Revit, you're right to be concerned about the model complexity as a whole, and it's crucial to nip this in the bud before you start populating your scene in Lumion. I suggest we carry out a feasibility study before we tackle the placement of the 4 house types first, as we need to figure out how much you can optimise the models and how your PC will cope with the 60 houses):

1) My recommendation would be to start thinking about the camera angles you'll need, and based on that, you should hide smaller details and other (unseen) parts of the buildings in the 3D Views you're going to export from Revit. Round surfaces are particularly important to hide as they are the most detailed surfaces. For example, if you've got a fully modelled bathroom but you aren't planning on rendering this room type, you should hide all the models in that room in your "optimised" 3D View before exporting the model.

2) In addition, you'll need to experiment with the Surface Smoothing slider in the export options in Revit. This slider determines how complex rounded surfaces such as tubes and cylinders will be during export. The goal is to set the slider to the lowest possible value that you can get away with (whilst ensuring that there aren't any obvious "blocky" eyesores in full view of the camera angles you've planned in step 1).

3) Once you're done with step 1 and 2, import each of the 4 houses as separate (.DAE file) buildings in Lumion, and then place the 15 duplicates of each house, so that the 60-odd houses are visible on the screen at the same time. The real-world positions are not important at this stage.

4) Then press the F4 key to select 4-star quality (the best preview quality option in Build mode).

Move the mouse cursor to the small white square in the top right corner, and let us know what the 3D Point number and FPS number are.

5) Please also attach a screenshot of your benchmark results screen (click on the bar that shows the overall benchmark result to access the more detailed benchmark screen).

Once we've got this information, we can start to look at how to place the 4 house types in eir real-world positions with less effort in Lumion.

6) By the way, which version of Lumion are you using?

The limited 7-day Lumion 7.5 Trial version (available on the 'Try' page) or the fully functional 7-day Lumion 7.5 Pro Trial version (available via your local reseller)?

The reason I ask is that if you're using the former, I should mention that scenes made in the limited 7-day Lumion 7.5 Trial version cannot be opened in other versions of Lumion (this is by design). Scenes made in the fully functional 7-day Lumion 7.5 Pro Trial version are not affected by this limitation.

I'm just bringing it up in case you end up purchasing a license after evaluating Lumion as I wouldn't want you to lose any sleep over lost work so to speak.

Hope that makes sense.

[Dragooon]

Thank you for such a detailed reply, I really appreciate it. I am using the Pro Trial, so I should be okay I believe.

1. I hadn't even considered hiding the objects which aren't going to be visible in my renders. Do objects which aren't visible in a view still impact performance? I am guessing Lumion would still need to figure out which objects to show and all so that might cause quite a bit of slowdown. 
2. Is there a way to group things like lights and plantation within Lumion which I could then copy-paste on the same type of buildings? I thought about organising them in layers and then copy-pasting them, is there a more efficient way?

I'll follow the steps as soon as I get some time and give you the feedback, thank you!

[Morten]

I am using the Pro Trial, so I should be okay I believe.

Indeed, should you decide to purchase Lumion at some point in the future, you'll be able to load the scenes and imported models without any problems. Please note that you can ask for an extension if required, once the 7 days are up.

Do objects which aren't visible in a view still impact performance?

Trees and plants do, but the rest don't. The socalled bounding box of each object is used to determine whether an object is rendered or not. This is another reason why 60 separate buildings will work better in Lumion than 60 buildings exported as one object; Lumion will only render buildings with bounding boxes that intersect the camera view frustrum. Needless to say, this helps with performance and render times.

2. Is there a way to group things like lights and plantation within Lumion which I could then copy-paste on the same type of buildings? I thought about organising them in layers and then copy-pasting them, is there a more efficient way?

There's currently no Group function in Lumion, so for the time being, I would recommend selecting the relevant lights and trees/plants, switch to Move mode and then holding down the ALT key while moving them in order to duplicate the selected objects.

Using Layers is a great way to organise the models in distinct categories. You've got up to 20 Layers at your disposal. There are also Show/Hide Layer effects in Photo and Movie mode which will let you toggle layer visibility, so that you can hide models that aren't required in a particular image or video.

Let us know if there's anything else we can help with.