Splitting imported models

Question

Good evening,

In order to streamline the process of calculating program at a project-wide level, we would like to be able to import models generated with other software (Rhino, for example) and use CityEngine to quickly come up with GFA by program type, FAR, etc.

To do this, we wrote a simple script that imports a model as .OBJ, splits that model into "floors" based on an input floor height, reports floor areas, and displays the models split into floors and colored by land use. No problem, right?

This works like a charm as long as you deal with small models - one block at a time, simple geometry, etc. But as it becomes more complicated, the script falls apart for some reason. Here are some screen shots from my own tests showing this problem.

1) Original Rhino file for the test...I've added 4 different model "types" to test out.
[ATTACH=CONFIG]15798[/ATTACH]

2) Single building - works great!
[ATTACH=CONFIG]15799[/ATTACH]

3) Two buildings - also works great!
[ATTACH=CONFIG]15800[/ATTACH]

4) Simple block - 8 different buildings and still working!
[ATTACH=CONFIG]15801[/ATTACH]

5) Complex block - circles, funky angles, and still working!
[ATTACH=CONFIG]15802[/ATTACH]

Some examples of this NOT working following the break.....5 images is the max per post....

3-many.jpg

1-single.jpg

4-complex.jpg

2-multiple.jpg

rhino file.jpg

MatthiasBuehler1 · Answer

hey Dan !

sorry for the late reply, I was in holiday.

maybe it's easier if I can communicate directly with you or one of your team who knows Rhino well.

there's so many dependencies involved that it'd be easiest to have a quick video chat.

I'm not sure if you have my mail address ? otherwise, just PM me.

let me know ! 🙂

Anonymous User · Answer

Original User: Daniel.OShaughnessy

Hi,

Yes, thanks for the explanation. All makes good sense.

Unfortunately, I was hoping to be able to import an entire model en masse. Despite the issue of buildings not being split into even floors, I was hoping this could give us a quick snapsnot of where we were programmatically.

It seems like Rhinoscript might be a good way to export buildings individually as OBJs. Then could we import all the buildings at once into CityEngine, or would it require knowledge of Python?

MatthiasBuehler1 · Answer

hi !

1]
this is actually tricky because each block is split as a whole object. better would be to have individual objects. currently, there's no way to split an obj asset into it's submeshes. I assume this produces the problems.

imagine if you have 3 buildings with 5, 15 and 25 floors --> you'd want to split each building into as many full floors as possible. but if your input is just 1 assets, the assumption is that you want to split the full object into as many floors as possible, basically ignoring the 'mathematical topology' and it's 'architectural semantics' you're interested in.

2]
ok, the fewer polygons the better due to any precision issues which usually happen with computers.

3]
see 2] 🙂

4]
thanks for the code, but I guess the trick is mentioned in 1]. You're also noticing that behavior the fewer buildings you have.

--> try to work with 1 obj asset for each building, not for each block.
Maybe one of your co-workers knows a little Rhino-Script and Python in CityEngine, which may speed up the workflow with new versions / large datasets.

let me know if this all makes sense.