[Tool] Surfaces on Mesh

[weiser]

Hi there,

after posting a Tool

- for converting polyline-crossections to 2D-splines for building up CAD-geometry from mesh-models (https://forums.autodesk.com/t5/inventor-forum/tool-convert-polyline-to-spline-2d/m-p/8779347)  and

- for building curves on a mesh-model-surface (https://forums.autodesk.com/t5/inventor-forum/tool-curves-on-mesh/td-p/8830791)

here is another tool for re-engineering mesh-models which enables you to pick three or four points on the mesh and connect them with a "mesh of lines", so you are able to generate a CAD-surface given by it's boundaries and internal railcurves.

NOTE: to use the tool you have to convert your STL-file with the Mesh-Enabler to a "CAD-triangulation".

You can choose 4 points to get a quadrangular surface. You can also generate a triangular surface-line-set by using the the same point-number on two surface-corners.

After calculating the set of curves for the surface a preview is shown where you can decide wether you want do keep the 3D-splines or not.

The process first finds the shortest path between the surface-corners, straighten the line in an iterative way where the points are smoothed and projected onto the surface. Later on a mesh of curves is generated within the given boundaries.

In the pictures you see some samples of the surfaces on the bunny-mesh. Don't worry about the coloured mesh-triangles - this is done manually for giving a reference.

There are still some disadvantages:

- the tool does not calculate any tangent at the end of the curves. So if you stitch two surfaces the transition might not be so smooth as in the mesh-model

- because most of the surfaces are calculated with different number of railcurves ther might be small gaps between two adjacent surfaces.

- the tool is, is relative time expensive. I think this could be optimized by using the algorithm within an plugin instead of VBA which is known to act rather slow ... or an implementation as an Inventor-feature by the autodesk coding team itself 😄

As the last time I hope that this will help some people out and maybe we can welcome that feature in Inventor in the future ....

Best Regards

User interface with bunny-modelMesh of curves on the mesh-modelBoudary-surface defined on the base of some curves (not all)Surface from another point of viewSurface without modelTriangular mesh of curvesTriangular boudary-surface with railcurves (again: not all curves are used)

[Xun.Zhang]

Great sharing!

[S_May]

@weiser 

sehr cool!!!

[weiser · Accepted solution]

Tanks for the positive feedback!

Though this is just an information and not an unanswered question, I'll close it by accepting this as an answer 😉

[MjDeck]

@weiser , I used Google Translate to read the text in the dialog. But I'm not sure how to pick the points to define a surface. Can you post a short demo video?

[weiser]

Hi @MjDeck 

sorry, but my users like to get things well done for using 😉

As I haven't worked with autodesk's screencast yet here is a litte introduction:

In the upper area you have to select the mesh-obejct you like to work with. This is done by picking a vertex, a face or an edge of the object and pressing "Übernehmen" (apply)

Followed by the next group right in the middle of the form.... there are 4 vertices to be picked. This can be done by picking one vertex and then applying it with the button "Eckpunkt 1, 2, 3, 4" (vertex 1,2,3,4). You also can pick all 4 vertices at once and then press one of the "Eckpunkt"-buttons. Then you weill be asked if you like to apply all selected vertices. Just click on "Ja" (yes) fur using all vertices. The two additional text-fields can be used to refine the mesh, but I've never used them by myself 😉

After defining the vertices you have to calculate the  surface geometry by pressing the button "Flächengeometre berechnen". when finished you can preview / generate the surfaces-curves by pressing "Vorschau/Übernahme".

Hope that helps?! If not, let me know!

Regards

[weiser · Accepted solution]

He there,

I'm very sorry ... but I've found an error within my alogorithm for finding the right mesh-face to project the smoothed point to. So here is the update for that.

Another improvement is, that the found points are generated as Sketch-points, which are now linked to the splines instead of generating them again for the splines.

Regards