Exporting to 3DS smoothness/accuracy problem

[Anonymous]

When i export walls with arched windows and doors to 3DS/DWG, the trims and walls become warped. They are no longer flat surfaces.
It looks like the accuracy of the exported model is very poor, in plan view you can see the mesh points making up the wall and window trims moving in and out of the wall surface.
This is extremely visible in 3d views and renderings.

I have turned on Smooth and tried putting every value in the ArchiCad Photorendering settings to its highest, but it makes no change. I have also tried to change the exported file units but it has made no difference.

Any suggestions?

[Dwight]

The first thing that came to mind when I saw the image was [hairdresser voice] I don't think I can do ANYTHING with this model !! [end hairdresser voice]

1: The photorendering settings are irrelevant to a smooth 3DS export - these settings only deal with how the renderer interprets internal edges of faceted surfaces. If you look at an external surface, you still see facet edges.

2: Your image shows an arched trim that obviously did not make the leap to 3DS very well - what is the source of this element? Perhaps there is another way to make elements that will translate well. If, for instance the arched window trim is a TUBE command, perhaps the translator can't figure it out.....

3: What import settings to MAX do you use? Without being a MAX expert, I notice that in ArchiCAD, "smoothness" is determined by the import value, not the export value.

[Anonymous]

Hey there,

The source objects are standart doors and windows made with ArchiCad library parts (basic archicad library).
When I open the file in 3DMAX it does not ask for any specific setting for a 3ds import (only for other file types - dwg etc...).
I also tried to export to autocad as a dwg and the autocad reads the object in the same way, so my guess is that the error is in ArchiCad.

I am using ArchiCad 8 if that helps.

Thanks for the quick response and i hope we can find some solution for this.

Etai

[Ben Odonnell]

Etai ,
Is your origin a long way from 0,0?

I have just tested exporting a 3DS file and importing it into Lightwave and Rhino, didn't have a problem with either of them.

Cheers.
Ben

[Dwight]

Hey, Ben, He's in friggin' Australia!
That's as far from the origin as you can get!

[Anonymous]

I have been exporting to MAX since AC5.1 and have never had any problems. The usual approximation has always been sufficient. I suppose it might be the AC 8.0 which was a very buggy version - I actually haven't used it much, jumped to 8.1

Perhaps you should send your .pln file so we could try to reproduce your problem.

Just an example:

25cm wall
some arched window from AC Lib
working units cm in both applications
export to .3ds
units cm 1:1000 - never understood why you have to type 1000 when it's just 10 but that's the way it works

Here is the result:

[Ben Odonnell]

Dwight wrote:
Hey, Ben, He's in friggin' Australia!
That's as far from the origin as you can get!

Did I say origin? Isn't that a footballs match? Like, state of origin?

Any way, were is the origin? After moving from Australia to Sweden, I have still yet to find it!

It can't possibly be in Canada, can it?

Cheers.
Ben

[stefan]

3ds max (as most CAD/3D software) has a limited accuracy. This is usually never seen in real models, since the accuracy is high, but it is limited. Once you have put the whole model very far from the origin (X=0, y=0, z=0) then problems can occur.

You can try to play with the scale setting in the ArchiCAD export and also make sure the whole ArchiCAD model is close to the world origin.

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I've have some smoothing problems with 3ds max and they are usually related to the mesh not being correctly welded in 3ds max.

Try this: select the editable mesh in 3ds max. Go into "point"-mode and select all points. Weld, using a suitable treshold (which is dependent on the scene). This makes sure that all vertices that lie on top of eachother to be welded and thus shared in the mesh.

Using a smooth modifier cannot work correctly if the mesh is still unwelded.

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To check if the mesh is welded, try going into point-mode and select one single vertex (e.g. at a corner of a window). Move it and see if the mesh follows or breaks apart. If it breaks, you have to weld the vertices.

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There is a Maxscript plugin from Marc Lorenz http://plugins.angstraum.at/ which helps with importing 3ds-meshed from ArchiCAD into 3ds max.

[Anonymous]

Thanks guys,

the model was miles away from the origin, and once I moved it closer the problem was solved.

It all came about because i imported an AutoCAD base file to begin with and it came in very far from the origin.

All happy now

cheers