Invisible STL model

pblythe · 2005-06-29 04:33:11

Hi. I have been importing several STL part models into VERICUT without a problem, up to now. I have got two models which display the blue boundary box when highlighted in the component tree, but refuse to display themselves as solid models in VERICUT. I am exporting SOLIDWORKS models into STL for importing to VERICUT. Can you tell me if there are any bugs or things to watch for when importing models with the aforementioned procedure? Thanks Peter Blythe

GavinP · 2005-06-29 08:22:28

Hi Peter

From the description you give it sounds like a bad STL, probably has holes in it.

I am not familiar with Solidworks, many on here are, more likely there are some fixing tools available inside.

Best regards

Gavin

Louis Bigelow · 2005-06-29 23:19:59

look under
files, Convert, Polyfix
it may take a couple of passes to fix the polygon file.
Louis

SergeV · 2005-06-30 16:14:49

Hello Peter,

A STL model is made of a multitude of triangles to reproduce the shape of the part. Each triangle has a normal vector. The vector indicates which side of the triangle is inside or out.
For VERICUT to display the model correctly, the normal vectors of all the triangles must be consistants (all outward or all inward). Also the model must be all closed (watertight).

Polyfix is a converter that works on the mormal vectors. As Louis mentionned, sometimes it takes 3-4 iterations to fix a model. If there is a hole in the model, Polyfix will no repair it. You then might have to improve the STL output from SolidWork.

Note: I worked on the initial demo for your company. I used Polyfix to repair you model, it took 2 passes.

Mike Davis · 2005-07-01 13:36:16

I have seen similar problems. The difference is that when I import an STL it looks pretty good. However, when I start the similator at least half of the STL disappears. It was also a problem when I tried using auto-diff. I am using Cimatron.

SergeV · 2005-07-01 15:18:53

It is the same problem. Either gaps or inverted normal vectors. You can also try File > Properties > Stock Consistency Check. VERICUT will then verify for small holes in the model and will fix it. This is not a permanent change, it is done every time the simulation is started. It can cause a slight delay.

Louis Bigelow · 2005-07-01 18:57:02

O/K....
So the question in my mind is...
why do you not copy that bit of
"repair/non manifold solid" code
up into the polygon repair program?

Louis

SergeV · 2005-07-01 19:30:25

When the simulation is started, VERICUT takes the stock model (STL, Polygon or parametric) and creates an internal solid representation. VERICUT does not change the STL model but simply disregard small gaps.

Louis Bigelow · 2005-07-01 19:57:56

o/k...
Louis

chaddy Summy · 2005-08-15 06:27:16

I often find that if a triangle model isn't watertight Vericut has problems with it. I have to go back to the source file, make the surfaces watertight (using the master data model, that contains surfaces and not triangles) and re-export to a triangle file.

STL and other Triangle files do not contain any surfaces. They're a pain.

VERICUT Users' Forum

#1 2005-06-29 04:33:11

Invisible STL model

#2 2005-06-29 08:22:28

Re: Invisible STL model

#3 2005-06-29 23:19:59

Re: Invisible STL model

#4 2005-06-30 16:14:49

Re: Invisible STL model

#5 2005-07-01 13:36:16

Re: Invisible STL model

#6 2005-07-01 15:18:53

Re: Invisible STL model

#7 2005-07-01 18:57:02

Re: Invisible STL model

#8 2005-07-01 19:30:25

Re: Invisible STL model

#9 2005-07-01 19:57:56

Re: Invisible STL model

#10 2005-08-15 06:27:16

Re: Invisible STL model

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