SER431 Lecture 21

Advanced Graphics
NURBS III
(201811)

Transcript

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   SER 431
   Advanced Graphics
   Lecture 21: Non-Uniform Rational Basis Splines III
   Javier Gonzalez-Sanchez
   javiergs@asu.edu
   PERALTA 230U
   Office Hours: By appointment
   

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   Quiz 06 NURBS
   Solution
   

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3. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 2
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   Problem A
   https://github.com/javiergs/SER431/blob/master/Lecture20/nurbs_surface_controlled.cpp
   

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4. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 3
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   Problem A
   // NURBS
   // How many curves? How many control points per curve?
   // How many knots per curve? How many knots per inter-curve connection?
   // Order for U and V?
   // Offset for U and V?
   GLfloat ctlpoints[4][4][3] = {
   { { 20, 0, 20 } ,{ 0, 0, 20 },{ 0, 0, 20 } ,{ -20, 0, 20 } },
   { { 20, 0, 0 } ,{ 0, 20, 0 },{ 0, 20, 0 } ,{ -20, 0, 0 } },
   { { 20, 0, 0 } ,{ 0, 20, 0 },{ 0, 20, 0 } ,{ -20, 0, 0 } },
   { { 20, 0, -20 } ,{ 0, 0, -20 },{ 0, 0, -20 } ,{ -20, 0, -20 } }
   };
   GLfloat uknots[8] = { 0.0, 0.0, 0.0, 0.0, 3.0, 3.0, 3.0, 3.0 };
   GLfloat vknots[8] = { 0.0, 0.0, 0.0, 0.0, 3.0, 3.0, 3.0, 3.0 };
   

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5. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 4
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   Problem B
   https://github.com/javiergs/SER431/blob/master/Lecture20/nurbs_surface_controlled.cpp
   

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6. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 5
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   Problem B
   // NURBS
   // How many curves? How many control points per curve?
   // How many knots per curve? How many knots per inter-curve connection?
   // Order for U and V?
   // Offset for U and V?
   const int V_size = 9;
   const int U_size = 7;
   const int ORDER = 4;
   GLfloat ctlpoints[U_size][V_size][3] = {
   { { 0, -4, 0 }, { -4, -4, 0 } ,{ -4, 0, 0 }, { -4, 4, 0 }, { 0, 4, 0 }, { 4, 4, 0 }, { 4, 0, 0 }, { 4, -4, 0 }, { 0, -4, 0 } },
   { { 0, -2, 4 }, { -2, -2, 4 } ,{ -2, 0, 4 }, { -2, 2, 4 }, { 0, 2, 4 }, { 2, 2, 4 }, { 2, 0, 4 }, { 2, -2, 4 }, { 0, -2, 4 } },
   { { 0, -4, 8 }, { -4, -4, 8 } ,{ -4, 0, 8 }, { -4, 4, 8 }, { 0, 4, 8 }, { 4, 4, 8 }, { 4, 0, 8 }, { 4, -4, 8 }, { 0, -4, 8 } },
   { { 0, 0, 10 }, { 0, 0, 10 } ,{ 0 , 0, 10 }, { 0, 0, 10 }, { 0, 0, 10 }, { 0, 0, 10 }, { 0, 0, 10 }, { 0, 0, 10 }, { 0, 0, 10 } },
   { { 0, -1, 12 }, { -1, -1, 12 } ,{ -1, 0, 12 }, { -1, 1, 12 }, { 0, 1, 12 }, { 1, 1, 12 }, { 1, 0, 12 }, { 1, -1, 12 }, { 0, -1, 12 } },
   { { 0, -2, 14 }, { -2, -2, 14 } ,{ -2, 0, 14 }, { -2, 2, 14 }, { 0, 2, 14 }, { 2, 2, 14 }, { 2, 0, 14 }, { 2, -2, 14 }, { 0, -2, 14 } },
   { { 0, -4, 16 }, { -4, -4, 16 } ,{ -4, 0, 16 }, { -4, 4, 16 }, { 0, 4, 16 }, { 4, 4, 16 }, { 4, 0, 16 }, { 4, -4, 16 }, { 0, -4, 16 } }
   };
   GLfloat vknots[V_size + ORDER]= {0.0, 0.0, 0.0, 0.0, 2.0, 4.0, 4.0, 4.0, 6.0, 8.0, 8.0, 8.0, 8.0 };
   GLfloat uknots[U_size + ORDER]= { 0.0, 0.0, 0.0, 0.0, 1.0, 3.0, 5.0, 6.0, 6.0, 6.0, 6.0 };
   

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   Surfaces using OpenGL Support
   Animation
   

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8. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 7
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   Screenshot
   https://github.com/javiergs/SER431/blob/master/Lecture19/nurbs_flag.cpp
   

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9. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 8
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   Code
   #define V_NUMPOINTS 4
   #define U_NUMPOINTS 4
   #define V_NUMKNOTS (V_NUMPOINTS + 4)
   #define U_NUMKNOTS (U_NUMPOINTS + 4)
   // Knots
   GLfloat sknots[V_NUMKNOTS] = { 0., 0., 0., 0., 1., 1., 1., 1. };
   GLfloat tknots[U_NUMKNOTS] = { 0., 0., 0., 0., 1., 1., 1., 1. };
   // Control points - the Z values will be modified to make it wave
   GLfloat ctlpoints[V_NUMPOINTS][U_NUMPOINTS][3] = {
   { { 0., 3., 0. },{ 1., 3., 0. },{ 2., 3., 0 },{ 3., 3., 0. } },
   { { 0., 2., 0. },{ 1., 2., 0. },{ 2., 2., 0 },{ 3., 2., 0. } },
   { { 0., 1., 0. },{ 1., 1., 0. },{ 2., 1., 0 },{ 3., 1., 0. } },
   { { 0., 0., 0. },{ 1., 0., 0. },{ 2., 0., 0 },{ 3., 0., 0. } }
   };
   

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10. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 9
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    // wave the flag by rotating Z cords though a sine wave
    void display() {
    for (int i = 1; i< 4; i++)
    for (int j = 0; j< 4; j++)
    ctlpoints[i][j][2] = sin((GLfloat)i + angle);
    angle += 0.1;
    gluBeginSurface(nurbsflag);
    gluNurbsSurface(nurbsflag,
    V_NUMKNOTS, sknots, U_NUMKNOTS, tknots,
    3 * U_NUMPOINTS, 3,
    &ctlpoints[0][0][0], 4, 4,
    GL_MAP2_VERTEX_3);
    gluEndSurface(nurbsflag);
    }
    

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    Quiz 07
    

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12. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 11
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    Screenshot
    https://github.com/javiergs/SER431/blob/master/Lecture08/reflection.cpp
    

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13. Javier Gonzalez-Sanchez | SER431 | Fall 2018 | 12
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    Instructions
    1. Join the program for Shadows and Reflection (with the 3 boxes in a plain)
    2. Add to the program one flag in a staff
    3. Make the flag move (as shown before)
    4. Show the shadow of the staff and the shadow of the flag
    5. Show the reflection of the staff and the reflection of the flag
    

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14. jgs
    SER431 Advanced Graphics
    Javier Gonzalez-Sanchez
    javiergs@asu.edu
    Fall 2018
    Disclaimer. These slides can only be used as study material for the class SER431 at ASU. They cannot be
    distributed or used for another purpose.
    

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