I met the same problem with collada, obj or fbx export. I built my street graph with shapes files (import from IGN) and i assigned to the streets the rule : Example_Paris__2010_3/rules/paris.cga. I tested a lot of export combination, shape groups, no optimization, forced normals; merge mesh, maybe i missed the good one. The pavements and the curbs are not exported like i can see the models in the city engine viewport. In 3DSMAX : With shape groups there is a no connection between groups and without i got a strange deformation of the mesh. I join to this message the results. Maybe there is a simple thing to do.
city engine 2012.3 build 0124 (version 64 bits) 3DSMAX 2011 (32 & 64 bits) FBX plugin in 3DSMAX : 2013.1 view in city engine [ATTACH=CONFIG]15016[/ATTACH]
view in 3DSMAX (export from CE without shape group) [ATTACH=CONFIG]15017[/ATTACH]
view in 3DSMAX (export from CE with shape group) [ATTACH=CONFIG]15018[/ATTACH]
That is the classic 'wobble effect' you're experiencing.
If your data is geolocated, due to the projection, the coordinates of the points have huge values, e.g. (600'000 / 3'000'000 units in the XZ plane). This means in 3DS Max, the models appear FAAR away from the origin.
The issue is that with these large coordinate values, the different renderers have issues displaying those very precise numbers precise enough. CityEngine compensates for this internally, but whenever you export to those 3d formats, you'll have to make sure to address this issue ( unless you create your data near the origin anyway ).
What you must do in 2010.3 is to MOVE all your elements near the ORIGIN of the xyz cartesian coordinate system. Check the screenshot I attached. Use the mouse cursor and the Navigation Display to check the coordinates. Use the Input Field on top of the GUI to move precisely. ( Though you could also move directly in the viewport. )
In the current version, 2011.2, you get a specific exporter functionality for this, where you can export your dataset directly centered around the cartesian origin to prevent this 'wobble effect'.
It seems magic, there is no more flicking in 3DSMAX and Virtools. Pavements are perfects in both sofwares. our production chain : city engine <-> 3DSMAX -> 3DVIA VIrtools5 Now we got the road network, we can now finish the links corrections of the street graphs and work on the buildings integration. 🙂 I join a screen from 3DVIA Virtools 5 : this is the roads of Boulogne Billancourt with the cga paris rule. [ATTACH=CONFIG]15139[/ATTACH]