Best strategy to simplify/reduce/smooth complex surfaces

I’m receiving surfaced files that are coming out of GeoMagic Freeform. They are the typical high density surface patches that you’d see in a file coming out of a non-CAD application when converted to NURBS. I’ve worked with the supplier of the files and have had them reduce the density as low as they feel comfortable. Rhino doesn’t have any problem working with the files, but after I do my part with them, I hand them off to our CAD department to bring into SolidWorks to finish up to create tooling. SolidWorks chokes on these files, due to the file size and complexity (6 files like this are combined into 1 tooling file). I need to adjust sizing, volume and place them on a base with a fillet. In order to reduce file size for SW, I remove most of the base and recreate a new and much simpler one in Rhino. To reduce the file size/complexity further, I’ve tried rebuilding all of the individual patches to reduce the surface control point count, I’ve also used FitSrf on the individual patches, which seems to work a little better at simplifying the surface while keeping the detail. SolidWorks seems to be very picky when it comes to working with surfaced files and any slight imperfection along the edges of the patches get an error and causes problems. I think these imperfections are in the original files, but might get a little more pronounced after I try to clean them up and reduce the density. Other than a lot of trial and error/back and forth between Rhino and SW to find and fix the areas that SW doesn’t like, I was wondering if anyone might have some suggestions. Does anyone have some ideas to try or some experience in working with files like this in Rhino or SolidWorks?

The file size is too big to upload to the forum, so it can be downloaded here:

https://displaypack.box.com/s/oowojr12nfn5toi4cde7


I believe I helped you on tech with this file recently specifically regarding the rebuilding of certain surfaces that SW can’t handle… I hope that helped some.

In general, if the overall complexity of the auto surface patches is too heavy, I’d go back to the auto-surfacer and reduce the complexity if possible. It’s been a long time since I used these types of programs on a daily basis but I recall there being parameters to reduce the fit and patch count. If you start rebuilding to lesser densities in Rhino, you’ll have a lot of matching to do. The other option in Rhino would be to reverse engineer the original mesh manually but this negates the use of the auto-surfacer and adds time.

Brian, yes you did. That’s essentially what I’ve been doing. I send a completed file to the CAD department and they flag and pinpoint the surfaces that SolidWorks has issues with and then I go in and manually repair or rebuild those particular patches or patch seams. Sometimes a MatchSrf works, too. I thought I’d throw it out on the forum, as well, and see if anyone might have any other tips or tricks with this sort of scenario.

mcramblet,

Have you looked at RapidForm DesignX?

I know you can select areas of triangles in GeomagicStudio to fit the nurbs patches manually, which is a lot more work of course. DesignX takes it a step further, and you end up with a parametric model in SolidWorks format. Its is still not a push button solution, but appears to be faster than GeomagicStudio. I know Geomagic was working on a developing a similar product that would run as a plug in inside SolidWorks, but I don’t know if it has been released.

I haven’t, and even looking it up now, if falls into the 3D Systems Black Hole of products, name changes and acquisitions. I can’t keep track of the product lines.

I should say that we aren’t using GeoMagic products, these models are being created for us. I know the initial work is being done with Freeform Plus, but when they are exporting to NURBS for our use, I’m not sure what is being used to convert and surface the original voxel models. I know they aren’t using the auto-surfacing function in FreeForm, there is a lot of manual work that is taking place.

It’s amazing to see the type of work that can be created in Freeform Plus, with it’s sculpting capabilities. But it’s not nearly as seamless (sculpting to CAD) as it is indicated as being on their website and in their literature. At least not in the projects that I’ve been involved with and working with the exported surface data.

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I should have clarified that I was considering method to produce a better surface if you had access to the original data.

The surface issues might have been improved in the triangles to nurbs conversion, and to correct those downstream is more difficult.