WriteSTL Custom Function

Can we please see the file in older version for Mathcad 14.

Cheers.

Just attached

Below are screenshots of the contents of this file:

Generate STL (STereoLithography) file in Mathcad 14/15: http://communities.ptc.com/docs/DOC-4620

Thank you Vladimir for sharing this work.

You're welcome.

Hi Anna Giangregorio, Brent Edmonds, MathCad

Thank you for this upload.  Especially the source code so it can be now also be made for windows 7, 32 bit.

Very usefull and much appreciated.  STL is standard format read (or can be converted to CFD meshes) by many CFD open source fluid flow solvers.

Regards

Terry

Hi,

Function can be improved by adding the normals to the triangles making up the STL surface.  It only uses 0,0,0. 

Surface normals are used by software that uses STL files to determine which is the front and back orientation.  They can also be used with a trick to help calculate the area of a triangulated STL surface.

Here is adjusted cpp file.  Input is a matrix with now four instead of three rows per triangle.  First row is normal of face, followed by original three rows of coordinates of corners. 

MathCad can calculate these normals and adjust the matrix before submission to the writeSTL function.

>>>>>>>>>>>>>

Terry Hendicott 03/01/2014 4:21 PM

Hi,

Function can be improved by adding the normals to the triangles making up the STL surface.  It only uses 0,0,0. 

Surface normals are used by software that uses STL files to determine which is the front and back orientation.  They can also be used with a trick to help calculate the area of a triangulated STL surface.

Here is adjusted cpp file.  Input is a matrix with now four instead of three rows per triangle.  First row is normal of face, followed by original three rows of coordinates of corners. 

MathCad can calculate these normals and adjust the matrix before submission to the writeSTL function.

>>>>>>>>>>>>>

// WriteSTL.cpp : Defines the exported functions for the DLL application.
//

#include "StdAfx.h"roes
#include "mcadincl.h"
#include <stdio.h>
   
    LRESULT WriteSTLFunction( LPCOMPLEXSCALAR result,
        LPMCSTRING      filename,
                                LPCOMPLEXARRAY     mat );

    FUNCTIONINFO    WriteSTL =
    {
    "WriteSTL",                                    // Name by which mathcad will recognize the function
    "filename,mat",                                            // transpose will be called as WriteSTL(filename,mat)
    "returns a success"  ,                   // everything work?
    (LPCFUNCTION)WriteSTLFunction,                 // pointer to the executible code
    COMPLEX_SCALAR,                                  // the output is a result flag
    2,                                              // the function takes on 2 arguments
    { STRING, COMPLEX_ARRAY}    // the input type is a complex array
    };
   
   
    LRESULT WriteSTLFunction( LPCOMPLEXSCALAR result,
        LPMCSTRING filename,
                       LPCOMPLEXARRAY     mat   )
    {
        FILE *fp;
  int i;
  fp = fopen(filename->str,"w");
  // Mathcad matrices are col x row via API, not row x col like the rest of the world
  fprintf(fp,"%s\n","solid Mathcad_Surface");
  for (i=0; i<mat->rows; i+=4) {
   fprintf(fp,"facet normal %f %f %f\n",mat->hReal[0][i],mat->hReal[1][i],mat->hReal[2][i]));
   fprintf(fp,"outer loop\n");
   fprintf(fp,"vertex %f %f %f\n",mat->hReal[0][i+1],mat->hReal[1][i+1],mat->hReal[2][i+1]);
   fprintf(fp,"vertex %f %f %f\n",mat->hReal[0][i+2],mat->hReal[1][i+2],mat->hReal[2][i+2]);
   fprintf(fp,"vertex %f %f %f\n",mat->hReal[0][i+3],mat->hReal[1][i+3],mat->hReal[2][i+3]);
   fprintf(fp,"endloop\n");
   fprintf(fp,"endfacet\n");
  }
  fprintf(fp,"%s\n","endsolid Mathcad_Surface");
  fclose(fp);
        result->real = 1;
        return 0;               // return 0 to indicate there was no error
           
    }  

>>>>>>>>>>>>

Can provide the MathCad14 file with the small program that adds the normals but no idea how to upload a MathCad file only images of limited size and videos can be added in this web page.

Regards

Hi Terry,

this is great. I do not see your attached CPP file. can you email me? Then I can get it posted.

And I can share with VladimirN and maybe he'll update his Mathcad 14 version.

John