Polygon Limitations

[Anonymous]

Just looking for some advice as to how many polygons is to many for Archicad. We are modeling a new automotive dealership and are struggling with the importation of .3ds and c4d files and and told that many of these automotive models have polygon counts over 300,000. We can certainly bring those into Cinema 4D and drop that count down but having a target amount would be very helpful.

[Erwin Edel]

I would compare them to the car models included in the ArchiCAD library and use those as reference point (their polycount). You can install the polycount addon from graphisoft for this. You can find it from the goodies link in the help menu.

[Barry Kelly]

I'm sure it will also depend on your machine specs.
I am not aware of any recommended figures.

I would place a marquee around say 4 cars and view that in 3D.
Then try 8 cars and compare how that responds in 3D.
Then 12, 16, etc., until you find the tipping point.

As Erwin said you can use the polycount add-on to determine the total number of polygons as you go.

Barry.

[Barry Kelly]

It may also depend on how the object is scripted as well.

I have a decent machine (I think).
The attached basin has a polycount of about 20500.

20 copies in 3D is instantaneous when rebuilding the 3D view.
100 copies takes about 11 second to re-build the 3D window.
400 takes about 46 seconds - about 8.2 million polygons.

Actually navigating in 3D is not bad at all - just a little sluggish.
This is in version 18 and the object would have originally been a 3DS file I think then converted to a morph for editing and saved back as an object.

Barry.

[Laszlo Nagy]

Years ago there was a Big Building White Paper from Graphisoft that talked about polygon count. I searched on the net and found a copy:

https://www.consoft.ro/files/archicad/metode_de_lucru/files/ArchicadBigBuildingWhitePaper.pdf

It says the 0.2-1.0 Million polygon is a big file, while 2.0-3.0 million starts to become critical. Many years have passed since that writing, nowadays AC uses multi-core processors, is 64-bit so it can handle much larger and more complex models. I would say now a big model starts in the million polygon range.

[Anonymous]

So far our experience in converting .3ds or .c4d into gdl has been an issue. The files we are working with seem to have about 1.5 million polygons and we have been able to get one and only one to convert to some level of acceptability. I have attached a photo of what we see in Cinema 4D and Archicad. We also notice that often on import Archicad keeps asking for files that are associated with the .gds file that are not included in the original and so the attached shows those results. We have even go into Cinema 4D and resaved the file as a .3ds but with no change in the results.

Is there a more comprehensive tutorial on this as its is leading us to Autodesk or similar with it seems we have less issues with graphics.

[Eduardo Rolon]

Take in consideration that AC is a program for construction documents not a rendering or regular 3D program like C4D, Maya or others. For construction documents having detailed car objects is not a priority, same with napkins, fluffy pillows, trees etc.

Having said that if by some reason I need to place different car models within the AC file, what I would do in C4D is remove all unnecessary elements from the car model like steering wheel, seats, brake pads, etc

Conceptually I would have my cars have fully mirrored glass so that I can't see inside and have to import unnecessary stuff.

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Also in my experience the conversion of some 3D models depend on how they were made originally. This means that some will come in good enough in 3DS but not in DWG or using the "send to Archicad" command from C4D. There is no particular way on how to determine which will work except by trying the different methods.

My usual work flow is to import the file into AC using different methods then I would convert the resulting object to a Morph for clean up and resave as another object.
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You might also give this plugin a try

http://www.day8design.hu/modelport/

If you do let us know how it works.

[Richard Morrison]

Might also try this program (Accutrans) for reducing number of polygons: http://www.micromouse.ca/ At USD $20, it's worth a shot.

[Laszlo Nagy]

If we are thinking of a large ArchiCAD file as something that has millions of polygons in 3D, then any imported 3DS file should not be more than in the few thousands or at most tens of thousands of polygons range, depending on how many instances of that object will be placed in the file. If you have a car that is 20 thousand polygons and you place 25 of those, that is already half a million polygons, just the cars. A 1.5 million polygon car has more polygons than many ArchiCAD projects fully modeled. A simple Wall with no Doors or Windows in it is 6 polygons, you could have quarter of a million of those to give you 1.5 million polygons in 3D.
So one should always consider how many polygons such imported geometries will add to the project file and try to reduce their polygon count accordingly.

By the way, the Morph Tool also has some commands using which you can simplify its faces and surfaces to reduce polygon count.

[stefan]

I would place simplified (low-poly) cars, trees and furniture in ArchiCAD and leave high-poly quality props for the external rendering software, where they matter more. You don't want to wait 20 minutes for a facade drawing, just because of the car model in the garage...