very strange faces misplace problem

Hi guys,

Sort of new to grasshopper. I have exported some building footprints from Arcmap to build a base model with grasshopper.

I imported the dwg with no problems, but when i try to add planar surfaces to these closed polylines and extrude them, i found the surfaces were all misplaced.

When i rotate the model these misplaced surfaces jump around like crazy, and the x y z axis in the lower left hand corner also jumps in a wierd way.

I have tried exporting several versions of dwg with no luck, but After some figuring out it seems like a projection issue with rhino because it is also very strange when i carry out the exact same procedure in rhino. Also tried parallel projection in rhino, it's a bit better, the faces don't jump as crazy, but it still does funny things (zigzaggy surface edge)!

Any idea would be hugely appreciated!

Attachments:

screenshot.jpg, 1.1 MB
footprint_test.DWG, 616 KB

Replies to This Discussion

Permalink Reply by Dimitri Nikitin on February 28, 2011 at 4:43pm

Hi there,

rhino often makes this, when geometry is very far from the origin point (0,0,0)... dwg file looks like there a 4 "clusters" of objects far from each other and from origin... that might be a problem...

... try moving the geometry closer to the origin point..

hope it will help

Dimitri

Permalink Reply by nc on February 28, 2011 at 5:09pm

Hi Dimitri,

Thanks for the input, i have relocated the cplane to the middle point of the footprints, but still no luck...

Cheers,

Matt

Permalink Reply by Dimitri Nikitin on March 1, 2011 at 2:30am

Hi there again,

I think relocaring the cplane will not solve the problem, I also tried it on my pc and it did not help... the only thing worked for me was moving the geometry manually with snapping and Move tool to point 0,0,0 of the scene (it is not the same as CPlane, I think)... just type "0" when the Move tool asks for "Point to move to"

Hope this will work...

Dimitri

Permalink Reply by Mateusz Zwierzycki on February 28, 2011 at 6:22pm

- try to rescale model (to be as small as visible cplane grid)

- export (from ACad) your drawing to PDF format (seems to be more predictible sometimes)

- before saving your dwg file join all lines to polylines ( command line : pline -> multiple ->select all --> join -> enter twice ). this will make your drawing much cleaner.

"Also tried parallel projection in rhino, it's a bit better, the faces don't jump as crazy, but it still does funny things (zigzaggy surface edge)!"

"zigzaggy" may be caused by some kind of drawing simplification - see your dwg saving properties. eventually regen your drawing before saving (hardly possible it may affect, but have a try)

Permalink Reply by nc on February 28, 2011 at 7:13pm

Hi Mateusz,

Thanks for the suggestion, the pdf method made it work! you guys are very helpful, really appreciate it, this issue bugged me for a long time!

Cheers,

Matt

Permalink Reply by nc on February 28, 2011 at 9:14pm

Hi guys,

sorry to bother again. another problem of the same sort arises.

Mateusz suggested the PDF method to simplify the dwg file to correct the face misplace error i was having.

It worked when i tried to extrude 1 building footprint, but for some reason when i input all the building footprint for GH to extrude it only managed to display surfaces for several buildings, others are displayed as wire frame. It's makes no sense to me...

Any ideas guys?

Cheers,

Matt

Permalink Reply by Mateusz Zwierzycki on March 1, 2011 at 1:48am

only idea is

- before saving your dwg file join all lines to polylines ( command line : pline -> multiple ->select all --> join -> enter twice ). this will make your drawing much cleaner.

Permalink Reply by nc on March 1, 2011 at 4:48pm

hi guys,

It's working properly now after i clean up the overlapping line work, and move the lines to the origin.

Thanks for all the help!

Cheers,

Matt

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