Hi guys & gals,

I am trying to create the sweep function that is generally found in all 3d rendering applications. I would like to sweep/extrude a 2d object, such as circle, along a predefined 2d path hence creating a 3d shape. I want to rotate this 2d shape so that it becomes perpendicular to the 2d path. Here is the code i'm currently working on, where vertices is the 2d shape and path is the 2d path. I'm calculating the gradient of any two points along the path and use it to calculate the angle of rotation so that is perpendicular to the path. Then using a rotational matrix i'm rotating the 2d object according the angle. However, I'm not achieving the desired results. Anyone can help me about this please?!

//This is the rendering of the 2D object swept along the path
 beginShape(QUAD_STRIP);
 for(int k = 0; k < path.length-1; k++){
   for(int i = 0; i < vertices.length; i++){
     float m1 = (path[k+1].y-path[k].y)/(path[k+1].x-path[k].x);
     float angle = (atan(m1));
     vertex((vertices[i].x*cos(angle) - vertices[i].y*sin(angle)) + path[k].x, (vertices[i].x*sin(angle) + vertices[i].y*cos(angle)) + path[k].y, path[k].x);
     vertex((vertices[i].x*cos(angle) - vertices[i].y*sin(angle)) + path[k].x, (vertices[i].x*sin(angle) + vertices[i].y*cos(angle)) + path[k].y, path[k+1].x);
   }
 }
 endShape();