Dense Mesh Models

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ssw
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Joined: Tue Feb 01, 2011 12:39 am

Dense Mesh Models

Post by ssw »

Hello,

I'm looking for some advice regarding efficiencies when computing toolpaths for dense meshes.

I have models containing no NURBS, just dense meshes derived from grayscale images. Also known as height maps. The toolpath calculations are taking FOREVER!

Any advice?

Thanks.
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Re: Dense Mesh Models

Post by MecSoft Support »

You will have to decimate the meshes since the Z height meshes are usually very dense and the density does not really give us any additional information.
ssw
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Joined: Tue Feb 01, 2011 12:39 am

Re: Dense Mesh Models

Post by ssw »

MecSoft Support wrote:You will have to decimate the meshes since the Z height meshes are usually very dense and the density does not really give us any additional information.
Hello and thanks for the reply.

I understand. I have worked with these meshes previously for purposes of 3D printing. I use the "Mesh Reduction" command on those with great success.

However I am now attempting to create Lithophanes on my CNC router. I generate the beautiful photo mesh using Rhino Emboss. These meshes have photo detail and need to stay "somewhat" dense. See example below. Vectric makes an app called "Photo Carve". I've watched their demo and see their tool paths generated in a few seconds.

I don't want to buy more software and really believe that RhinoCAM can do this. Can you help?

Thank You,

Bernie
Lithophane_1.jpg
Lithophane_1.jpg (8.77 KiB) Viewed 17864 times
ssw
Posts: 10
Joined: Tue Feb 01, 2011 12:39 am

Re: Dense Mesh Models

Post by ssw »

MecSoft Support wrote:You will have to decimate the meshes since the Z height meshes are usually very dense and the density does not really give us any additional information.
Do we know for sure that it's the mesh density that is causing the slow computing? Afterall, RhinoCAM does use the render mesh to calculate tool paths from NURBS as well, correct?

-- Bernie
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Re: Dense Mesh Models

Post by MecSoft Support »

Hi Bernie,
I am not sure these mesh densities are what causes the slow toolpaths. Usually the Z height fields computed by our ART module can be toolpath'ed in seconds. Also comparing the speed with Vectric does not give us any additional information since as I say the meshes generated from our ART module see to pose no problems at all. I am assuming that the meshes you are getting from Photo Emboss are too dense. Examining the triangle count on these meshes should give you a good idea if the meshes are too dense or not.
ssw
Posts: 10
Joined: Tue Feb 01, 2011 12:39 am

Re: Dense Mesh Models

Post by ssw »

MecSoft Support wrote:Hi Bernie,
I am not sure these mesh densities are what causes the slow toolpaths. Usually the Z height fields computed by our ART module can be toolpath'ed in seconds. Also comparing the speed with Vectric does not give us any additional information since as I say the meshes generated from our ART module see to pose no problems at all. I am assuming that the meshes you are getting from Photo Emboss are too dense. Examining the triangle count on these meshes should give you a good idea if the meshes are too dense or not.
I will do some more tests. I know there are other factors that can lead to long tool path compute times.

In the Rhino Emboss project settings, the minimum mesh dimensions are 1000 x 1000. That would be 1,000,000 quads, or 2 million triangles. How dense are the meshes in RhinoART? What is TOO dense?

Thank you,

Bernie
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Re: Dense Mesh Models

Post by MecSoft Support »

2 Million triangles is getting to the upper limits on a 32 bit system. And of-course the computation time will be reduced because of this. Have you tried our ART module, we do have built in triangle decimation.
ssw
Posts: 10
Joined: Tue Feb 01, 2011 12:39 am

Re: Dense Mesh Models

Post by ssw »

MecSoft Support wrote:2 Million triangles is getting to the upper limits on a 32 bit system. And of-course the computation time will be reduced because of this. Have you tried our ART module, we do have built in triangle decimation.
I have looked at the ART module. It shares many feature with Rhino Emboss. I am still in trial period with RE.

I am a RhinoCAM Annual Maintenance customer. I understand there may be special pricing? Can I get a quote for the ART module?

Thanks,

Bernie
ssw
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Joined: Tue Feb 01, 2011 12:39 am

Re: Dense Mesh Models

Post by ssw »

Hello,

I have made some progress. I'm finding that it's not the number of triangles that causes the problems. It's how tight they fit in a given area. This is defined as the "resolution". I should have known that! For example, 1 million polys in a 2 cm x 2 cm area has issues, but 1 million polys in a 20 inch x 20 inch area works okay.

So, I think I'm on the right track.

Thanks for the help.

-- Bernie
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Re: Dense Mesh Models

Post by MecSoft Support »

Please drop an email to [email protected] and our sales department can provide you a quote for the ART module.
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