Keyshot exports - duplicate vertices

Started by BJT_DAVE, July 31, 2019, 03:55:13 AM

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BJT_DAVE

I notice that when I export a model from Keyshot 7 as an fbx or obj that the faces are all separated ie the mesh is not connected (non-manifold), resulting in 20 million vertices on a model that began with only 3 million. My question is, when a model is imported into KS does KS split all the faces into individual triangles at that point or is it only when it exports a file?

Bruno F

Hello BJT_DAVE,

Thank you for posting your question. The number of vertices is a function of the tessellation value. I am not entirely sure, but it is possible the the exporter uses a default high tessellation value to ensure high quality. Unfortunately, when you export KeyShot files, it is not possible to control this value. To answer your question, the tesellation for certain formats is set at export (from KeyShot or your CAD application). However, some of our importers do offer a tesellation multiplier (tessellation slider) at import for certain CAD files: .sldprt, .sldasm, STEP, to name a few. KeyShot will work its magic, translate 3D data, and split faces into triangles at import.

BJT_DAVE

Hi Bruno, what I meant was that the triangles on the mesh are all separate ie the vertices are not connected. If I export an fbx and open it in Blender I can select a triangle and pull it away from the mesh because they are all separate, resulting in a huge number of duplicate vertices. It creates a lot of work to clean up all the doubles, clear split normals and resmooth surfaces. Why does keyshot do this? You can have a hexagon for example made from 6 triangles which needs only 7 vertices to create (6 around the edge and one in the centre) ....but keyshot will export it with 18 vertices (3 for each triangle with 6 stacked at the centre).

Bruno F

Hello BTJ_DAVE,

Thank you for clarifying. To be honest, I am not sure why KeyShot does this. The first step is to reproduce this behaviour on our end and then file a bug to be fixed in a later version. Thank you for reporting!

DMerz III

hmm - good catch BJT-Dave, that would explain why the file sizes are enormous and importing back into Blender is causing some unsavory processing times.