SER332 Lecture 18

Introduction to Graphics and Game Development
Mesh Data Structure II
(201804)

Transcript

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   SER332
   Introduction to Graphics and Game
   Development
   Lecture 18: Mesh Data Structure II
   Javier Gonzalez-Sanchez
   javiergs@asu.edu
   PERALTA 230U
   Office Hours: By appointment
   

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   Plane, Cylinder, and Box
   

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3. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 3
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   Creating a Triangulated Plane
   // Generate vertices in XZ-plane
   for i = 0 to n
   for j = 0 to n
   Create vertex at location (i*xsize, 0, j*ysize)
   // step 2. Generate indices
   for i = 0 to ?
   Create triangle with indices(i, i+1, i+n+1)
   Create triangle with indices( i+1, i+n+2, i+n+1)
   xsize
   ysize vn
   v0
   v1
   v
   n+1
   vn+2
   

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4. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 4
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   Creating a Triangulated Plane
   // creating a triangulated plane
   Mesh* createPlane(int arena_width, int arena_depth, int arena_cell) {
   Mesh *me = new Mesh;
   int n = arena_width / arena_cell;
   int m = arena_depth / arena_cell;
   // vertices
   for (int i = 0; ifor (int j = 0; j < m; j++) {
   me->dot_vertex.push_back(Vec3(i*arena_cell, 0.0, j*arena_cell));
   }
   }
   // faces
   for (int i = 0; i<(n*m) - m; i++) {
   if ((i + 1) % n == 0) continue;
   me->face_index_vertex.push_back(i);
   me->face_index_vertex.push_back(i + 1);
   me->face_index_vertex.push_back(i + n);
   me->face_index_vertex.push_back(i + 1);
   me->face_index_vertex.push_back(i+ n + 1);
   me->face_index_vertex.push_back(i + n);
   }
   return me;
   }
   

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5. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 5
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   Creating a Triangulated Plane
   § Use colors to verify right-hand rule.
   

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6. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 6
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   Creating a Triangulated Cylinder
   // Generate vertices on top
   for i = 0 to n
   angle = (i*360) / (n+1)
   create vertex at (cos( angle), height, sin(angle))
   // Generate vertices on the bottom
   // same process but height = 0
   // Generate vertex in the middle of the top
   // Generate vertex in the middle of the bottom
   // Generate triangles on top
   // Generate triangles on the bottom
   // Generate triangles on the side
   v1
   Vn+2
   v0
   Vn+1
   

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7. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 7
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   Creating a Triangulated Cylinder
   // create a triangulated cylinder
   Mesh* createCylinder(int h, int radio) {
   int n = 100;
   double angle;
   Mesh *m =new Mesh;
   // Generate vertices on top
   m->vertex.push_back(Vec3(0.0, h, 0.0));
   for (int i = 0; iangle = (M_PI/180)*(1.0*i*360)/n;
   m->vertex.push_back(Vec3
   (cos(angle)* radio, h, sin(angle)* radio));
   }
   // Generate vertices on bottom
   for (int i = 0; iangle = (M_PI/180)*(i*360)/n;
   m->vertex.push_back(Vec3
   (cos(angle)* radio, 0.0, sin(angle)* radio));
   }
   

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   Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 8
   // Generate triangles on top
   for (int i = 1; i<=n; i++) {
   m->vertexIndex.push_back(0); m->vertexIndex.push_back(i);
   if (i==n) {
   m->vertexIndex.push_back(1);
   }else{
   m->vertexIndex.push_back(i+1);
   }
   }
   // There is no bottom. Use the floor.
   // Generate triangles on the side
   for (int i = 1; i<=n; i++) {
   m->vertexIndex.push_back(i); m->vertexIndex.push_back(n+i);
   if (i!=n) {
   m->vertexIndex.push_back(n+i+1);
   } else {
   m->vertexIndex.push_back(n+1);
   }
   m->vertexIndex.push_back(i);
   if (i!=n) {
   m->vertexIndex.push_back(i+1); m->vertexIndex.push_back(n+i+1);
   }else{
   m->vertexIndex.push_back(1); m->vertexIndex.push_back(n+1);
   }
   }
   return m;
   }
   

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9. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 9
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   Creating a Triangulated Cylinder
   

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10. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 10
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    Creating a Triangulated Cube
    // Generate vertices on top
    // Generate vertices on the bottom
    // Generate triangles on top
    // Generate triangles on the bottom
    // Generate triangles on the sides
    

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11. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 11
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    Creating a Triangulated Cube
    

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12. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 12
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    Source Code
    § https://github.com/javiergs/SER332/blob/master/Lecture18/main.cpp
    

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13. Javier Gonzalez-Sanchez | SER332 | Spring 2018 | 13
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    Test Yourselves
    § Include methods to create cubes, planes, and cylinders
    § Include methods to create spheres
    

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    SER332 Introduction to Graphics
    Javier Gonzalez-Sanchez
    javiergs@asu.edu
    Spring 2018
    Disclaimer. These slides can only be used as study material for the class SER332 at ASU. They cannot be distributed or used for another purpose.
    

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