I do alot of work with architecture firms and designers.
They all seem to be using different CAD programs. (Rhino, 3DS Max, Revit and google sketch up).
Does any one know of a good file converter I can buy or trial?
SolidWorks will open Rhino files
I and my staff pioneered and have produced the main conversion system over the last 25 years. I am one of the most experienced people in the conversion industry, with most of my main business coming from SolidWorks users each second hour since 1996. However, I'll first note that you cannot "convert" from non-CAD programs like SketchUp and 3ds Max into SolidWorks. The #1 epidemic of a question I get 3-6 times every day is of people wanting to bring in non-CAD (ie. mesh) assets into SolidWorks, as that is not a "conversion" process but rather a re-surfacing process of turning mesh data into NURBS for SolidWorks (I have a common 5 page email which I send out explaining the $5k to $25k programs which can do that, but no one really ends up doing so).
1) Rhino is a combined mesh/NURBS modeller. Hence, if the Rhino model was created purely as NURBs, and better yet "solids" (NURBS with topology info) then that is geometry-wise compatible with SolidWorks.
2) Revit is a very old 1990's era technology program and hence is built upon the ACIS modelling kernel. Thus, you could accept an ACIS SAT file from those customers. But the best way, via DWF-3D, is mesh based and hence can't be blindly imported into SolidWorks.
3) 3ds Max: we wrote the first and main conversion system for 3ds Max 20 years ago this year so we know it all too well. 3ds Max is primarily a mesh modeller and hence you can't import .max files. Second, no program in the entire world can read or write .max files, so the conversion usually occurs on the 3ds Max side.
4) SketchUp. We wrote the first and only professional SketchUp conversion system along with its developer in 2004/2005 before the company was sold off and little done with SketchUp thereafter. As noted, SketchUp is a very trivial mesh modelling program and has no bearing with "CAD" at all. It's at the extreme end of the universe compared to SolidWorks which is the #1 main MCAD modeller.
5) Thus, in basic terms, you can accept data easily from other true MCAD modellers such as Inventor, ProE, UG NX, CATIA, etc. but not from mesh based programs. $99 plug-ins from India which promote "Mesh to solids" are all smoke & mirrors, as they do nothing more than my own IGES exporter which turns each triangle into a bilinear NURBS surface -- that will kill SolidWorks after just 1000 triangles, so in no sense is this proper "mesh to solids/NURBS" conversions.
Some refs related to my comments above, but which will not likely be related to your requirements:
We write and sell the main conversion system for sourcing architectural models (in particular, in 2013 with it being the most popular, from Revit/NavisWorks, and for the mass-market, from SketchUp). The DWF importer is the primary means to get proper + full conversions from most of the current architectural programs - don't touch DXF/DWG as that's the second worst file format after STL. Normally you wouldn't import full architectural models into SolidWorks but you'd do the opposite by taking SolidWorks models into architectural or other layout programs for rendering and animation.
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