将多个Stl文件合并为一个

Question

I am working with asp.NET MVC 5, I have found ac# code to display a stl file on my browser, now I would like to combine it with another stl file. I found that VTK allows you to do this : http://www.vtk.org/Wiki/VTK/Examples/Cxx/Filtering/CombinePolyData . But the code is in .cxx, I suppose that I can't use it on a Web application ?

Answer 1

The STL-format is just a triangle soup, that is, a collection of triangles without any connectivity information. Analogously to mixing two soups in one pot in real life, nothing prevents you from putting all the triangles from both your files into one before displaying them.

More precisely, suppose that file1.stl looks like

solid model1
  facet normal 0.0 0.0 -1.0
    outer loop
      vertex 20.0 0.0 0.0
      vertex 0.0 -20.0 0.0
      vertex 0.0 0.0 0.0
    endloop
  endfacet
.
.
.
  facet normal 0.0 0.0 -1.0
    outer loop
      vertex 0.0 -20.0 0.0
      vertex 20.0 0.0 0.0
      vertex 20.0 -20.0 0.0
    endloop
  endfacet
endsolid

(the dots suggest further triangles and would not be present in the actual file) and file2.stl as

solid model2
  facet normal -0.0 1.0 0.0
    outer loop
      vertex 0.0 0.0 20.0
      vertex 20.0 0.0 0.0
      vertex 0.0 0.0 0.0
    endloop
  endfacet
.
.
.
  facet normal -0.0 1.0 0.0
    outer loop
      vertex 20.0 0.0 0.0
      vertex 0.0 0.0 20.0
      vertex 20.0 0.0 20.0
    endloop
  endfacet
endsolid

I am not an expert in C# but it should be a fairly easy exercise on string manipulation to put both of these models into one file result.stl :

solid bothModelsInOne
  facet normal 0.0 0.0 -1.0
    outer loop
      vertex 20.0 0.0 0.0
      vertex 0.0 -20.0 0.0
      vertex 0.0 0.0 0.0
    endloop
  endfacet
.
.
.
  facet normal 0.0 0.0 -1.0
    outer loop
      vertex 0.0 -20.0 0.0
      vertex 20.0 0.0 0.0
      vertex 20.0 -20.0 0.0
    endloop
  endfacet
  facet normal -0.0 1.0 0.0
    outer loop
      vertex 0.0 0.0 20.0
      vertex 20.0 0.0 0.0
      vertex 0.0 0.0 0.0
    endloop
  endfacet
.
.
.
  facet normal -0.0 1.0 0.0
    outer loop
      vertex 20.0 0.0 0.0
      vertex 0.0 0.0 20.0
      vertex 20.0 0.0 20.0
    endloop
  endfacet
endsolid

Notice that all the facets (triangles) are in one file but there is only one solid / endsolid pair enclosing the model.

Now you can pass this file to your renderer as you did before.

This quite certainly does the job when the two bodies are disjoint. Whether it does what you want in case of an intersection would require you to provide a more precise definition of "combine".