Drape tool problem

zook247

On several different occasion now I have tried to drape some linework with some filled faces over a simple terrain. Each time numerous lines and filled faces are missing. Do you what might be the cause for this? What am I doing wrong? Thanks.

TIG

Very tiny geometry can't intersect.
SketchUp's tolerance is ~1/1000th".
So a resultant very short line might have its two vertex points so close that SketchUp takes them as coincident, therefore it doesn't make the edge and then any face associated with the missing edge can't be formed either...

Try scaling up x100 or x1000, do the processing and then scale back down again...
That might give SketchUp a fighting chance.
Tiny geometry can exist [like after you scale down] but t can't be created...

zook247

OK, so what I believe you are saying is that I should try super enlarging both the entities I want to drape and the mesh I want to drape upon, perform the drape at that scale and then reduce the result back down to the original scale. Is that correct?
Thanks

olishea

See this thread also. Exact same problem and yes that is what TIG is suggesting.

http://sketchucation.com/forums/viewtopic.php?f=15%26amp;t=55415

zook247

I tried the drape at 1000x enlargement, same result. If there are tiny gaps they are certainly not visible to the eye and the faces fill on the undraped entities. Do you think TTs cleanup or something like it might work in this case?

mitcorb

Hi zook:
The time/date stamp appears as if you are located somewhere in the Atlantic Ocean. I first looked at your last comment at 1:03 pm my time.

As for ThomThom's Cleanup, yes probably worth a try.

olishea

why not post the model or at the very least an image?

zook247

I have been trying a few things. I took the site features I want to drape but instead of draping them I extruded them through the topography and did an intersection with model. Much to my surprise I had the exact same results as with the drape tool with the same lines missing.

As an experiment I did the same thing but using a simple face for a mesh. The intersection worked normally with all lines appearing.

This tells me that the problem is with the surface I am using as a mesh. There is something wrong with it. However, I don't know yet what it is. Anyone have any ideas? It is a very simple mostly flat topo with just a few grade changes. Thanks

olishea

Have you tried scaling your model up as suggested? Then reduce it back down once you have intersected?