此代码的目的是生成一个Y值随机变化的“表面”，然后使光源照在其上并生成亮度区域，并在较暗的区域执行阴影处理。问题是，这实际上没有发生。光要么照亮一侧，要么照亮另一侧，而这些侧面都均匀地变亮或变暗。我想念什么？请记住，还有很多代码需要删除，但这不是我的优先事项，我只是想在此时实现着色功能。
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#ifdef MAC
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
//Camera variables
int xangle = -270;
int yangle = 0;
//Control Mode (Rotate mode by default)
int mode = 0;
//Player Position (Y offset so it would not be straddling the grid)
float cubeX = 0;
float cubeY = 0.5;
float cubeZ = 0;
//Vertex arrays for surface
float surfaceX [11][11];
float surfaceY [11][11];
float surfaceZ [11][11];
//Surface Normal arrays
float Nx[11][11];
float Ny[11][11];
float Nz[11][11];
//Color arrays
float R[11][11];
float G[11][11];
float B[11][11];
// Material properties
float Ka = 0.2;
float Kd = 0.4;
float Ks = 0.4;
float Kp = 0.5;
//Random number generator
float RandomNumber(float Min, float Max)
{
return ((float(rand()) / float(RAND_MAX)) * (Max - Min)) + Min;
}
//---------------------------------------
// Initialize material properties
//---------------------------------------
void init_material(float Ka, float Kd, float Ks, float Kp,
float Mr, float Mg, float Mb)
{
// Material variables
float ambient[] = { Ka * Mr, Ka * Mg, Ka * Mb, 1.0 };
float diffuse[] = { Kd * Mr, Kd * Mg, Kd * Mb, 1.0 };
float specular[] = { Ks * Mr, Ks * Mg, Ks * Mb, 1.0 };
// Initialize material
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, ambient);
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuse);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, Kp);
}
//---------------------------------------
// Initialize light source
//---------------------------------------
void init_light(int light_source, float Lx, float Ly, float Lz,
float Lr, float Lg, float Lb)
{
// Light variables
float light_position[] = { Lx, Ly, Lz, 0.0 };
float light_color[] = { Lr, Lg, Lb, 1.0 };
// Initialize light source
glEnable(GL_LIGHTING);
glEnable(light_source);
glLightfv(light_source, GL_POSITION, light_position);
glLightfv(light_source, GL_AMBIENT, light_color);
glLightfv(light_source, GL_DIFFUSE, light_color);
glLightfv(light_source, GL_SPECULAR, light_color);
glLightf(light_source, GL_CONSTANT_ATTENUATION, 1.0);
glLightf(light_source, GL_LINEAR_ATTENUATION, 0.0);
glLightf(light_source, GL_QUADRATIC_ATTENUATION, 0.0);
glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, GL_FALSE);
glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
}
//---------------------------------------
// Initialize surface
//---------------------------------------
void init_surface()
{
//Initialize X, select column
for (int i = 0; i < 11; i++)
{
//Select row
for (int j = 0; j < 11; j++)
{
surfaceX[i][j] = i-5;
surfaceY[i][j] = RandomNumber(5, 7) - 5;
surfaceZ[i][j] = j-5;
//std::cout << "Coordinate "<< i << "," << j << std::endl;
}
//std::cout << "Hello world "<< std::endl;
}
//std::cout << "Coordinate -5,-5" << surfaceX[-5][-5] << std::endl;
}
void define_normals()
{
//Define surface normals
for (int i = 0; i < 10; i++)
{
for (int j = 0; j < 10; j++)
{
//Get two tangent vectors
float Ix = surfaceX[i+1][j] - surfaceX[i][j];
float Iy = surfaceY[i+1][j] - surfaceY[i][j];
float Iz = surfaceZ[i+1][j] - surfaceZ[i][j];
float Jx = surfaceX[i][j+1] - surfaceX[i][j];
float Jy = surfaceY[i][j+1] - surfaceY[i][j];
float Jz = surfaceZ[i][j+1] - surfaceZ[i][j];
//Get two tangent vectors
//float Ix = Px[i+1][j] - Px[i][j];
//float Iy = Py[i+1][j] - Py[i][j];
//float Iz = Pz[i+1][j] - Pz[i][j];
//float Jx = Px[i][j+1] - Px[i][j];
//float Jy = Py[i][j+1] - Py[i][j];
//float Jz = Pz[i][j+1] - Pz[i][j];
//Do cross product
Nx[i][j] = Iy * Jz - Iz * Jy;
Ny[i][j] = Iz * Jx - Ix * Jz;
Nz[i][j] = Ix * Jy - Iy * Jx;
//Nx[i][j] = Nx[i][j] * -1;
//Ny[i][j] = Ny[i][j] * -1;
//Nz[i][j] = Nz[i][j] * -1;
float length = sqrt(
Nx[i][j] * Nx[i][j] +
Ny[i][j] * Ny[i][j] +
Nz[i][j] * Nz[i][j]);
if (length > 0)
{
Nx[i][j] /= length;
Ny[j][j] /= length;
Nz[i][j] /= length;
}
}
}
//std::cout << "Surface normal for 0,0: "<< Nx[0][0] << "," << Ny[0][0] << "," << Nz[0][0] << std::endl;
}
void calc_color()
{
for (int i = 0; i < 10; i++)
{
for (int j = 0; j < 10; j++)
{
//Calculate light vector
//Light position, hardcoded for now 0,1,1
float Lx = -1 - surfaceX[i][j];
float Ly = -1 - surfaceY[i][j];
float Lz = -1 - surfaceZ[i][j];
std::cout << "Lx: " << Lx << std::endl;
std::cout << "Ly: " << Ly << std::endl;
std::cout << "Lz: " << Lz << std::endl;
//Grab surface normals
//These are Nx,Ny,Nz due to compiler issues
float Na = Nx[i][j];
float Nb = Ny[i][j];
float Nc = Nz[i][j];
std::cout << "Na: " << Na << std::endl;
std::cout << "Nb: " << Nb << std::endl;
std::cout << "Nc: " << Nc << std::endl;
//Do cross product
float Color = (Na * Lx) + (Nb * Ly) + (Nc * Lz);
std::cout << "Color: " << Color << std::endl;
//Color = Color * -1;
R[i][j] = Color;
G[i][j] = Color;
B[i][j] = Color;
//std::cout << "Color Value: " << std::endl;
////std::cout << "R: " << R[i][j] << std::endl;
//std::cout << "G: " << G[i][j] << std::endl;
//std::cout << "B: " << B[i][j] << std::endl;
}
}
}
//---------------------------------------
// Init function for OpenGL
//---------------------------------------
void init()
{
glClearColor(0.0, 0.0, 0.0, 1.0);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//Viewing Window Modified
glOrtho(-7.0, 7.0, -7.0, 7.0, -7.0, 7.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
//Rotates camera
//glRotatef(30.0, 1.0, 1.0, 1.0);
glEnable(GL_DEPTH_TEST);
//Project 3 code
init_surface();
define_normals();
//Shading code
glShadeModel(GL_SMOOTH);
glEnable(GL_NORMALIZE);
init_light(GL_LIGHT0, 0, 1, 1, 0.5, 0.5, 0.5);
//init_light(GL_LIGHT1, 0, 0, 1, 0.5, 0.5, 0.5);
//init_light(GL_LIGHT2, 0, 1, 0, 0.5, 0.5, 0.5);
}
void keyboard(unsigned char key, int x, int y)
{
//Controls
//Toggle Mode
if (key == 'q')
{
if(mode == 0)
{
mode = 1;
std::cout << "Switched to Move mode (" << mode << ")" << std::endl;
}
else if(mode == 1)
{
mode = 0;
std::cout << "Switched to Rotate mode (" << mode << ")" << std::endl;
}
}
////Rotate Camera (mode 0)
//Up & Down
else if (key == 's' && mode == 0)
xangle += 5;
else if (key == 'w' && mode == 0)
xangle -= 5;
//Left & Right
else if (key == 'a' && mode == 0)
yangle -= 5;
else if (key == 'd' && mode == 0)
yangle += 5;
////Move Cube (mode 1)
//Forward & Back
else if (key == 'w' && mode == 1)
{
if (cubeZ > -5)
cubeZ = cubeZ - 1;
else
std::cout << "You have struck an invisible wall! (Min Z bounds)" << std::endl;
}
else if (key == 's' && mode == 1)
{
if (cubeZ < 5)
cubeZ = cubeZ + 1;
else
std::cout << "You have struck an invisible wall! (Max Z bounds)" << std::endl;
}
//Strafe
else if (key == 'd' && mode == 1)
{
if (cubeX < 5)
cubeX = cubeX + 1;
else
std::cout << "You have struck an invisible wall! (Max X bounds)" << std::endl;
}
else if (key == 'a' && mode == 1)
{
if (cubeX > -5)
cubeX = cubeX - 1;
else
std::cout << "You have struck an invisible wall! (Min X bounds)" << std::endl;
}
//Up & Down (Cube offset by +0.5 in Y)
else if (key == 'z' && mode == 1)
{
if (cubeY < 5)
cubeY = cubeY + 1;
else
std::cout << "You've gone too high! Come back! (Max Y bounds)" << std::endl;
}
else if (key == 'x' && mode == 1)
{
if (cubeY > 0.5)
cubeY = cubeY - 1;
else
std::cout << "You've reached bedrock! (Min Y bounds)" << std::endl;
}
//Place/Remove block
else if (key == 'e' && mode == 1)
{
//Occupied(cubeX,cubeY,cubeZ);
}
//Redraw objects
glutPostRedisplay();
}
//---------------------------------------
// Display callback for OpenGL
//---------------------------------------
void display()
{
// Clear the screen
//std::cout << "xangle: " << xangle << std::endl;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
//Rotation Code
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glRotatef(xangle, 1.0, 0.0, 0.0);
glRotatef(yangle, 0.0, 1.0, 0.0);
//Light Code
init_material(Ka, Kd, Ks, 100 * Kp, 0.8, 0.6, 0.4);
calc_color();
//Draw the squares, select column
for (int i = 0; i <= 9; i++)
{
//Select row
for (int j = 0; j <= 9; j++)
{
glBegin(GL_POLYGON);
//Surface starts at top left
//Counter clockwise
// CALCULATE COLOR HERE
// - calculate direction from surface to light
// - calculate dot product of normal and light direction vector
// - call glColor function
//Calculate light vector
//Light position, hardcoded for now 0,1,1
///float Lx = 0 - surfaceX[i][j];
//float Ly = 1 - surfaceY[i][j];
//float Lz = 1 - surfaceZ[i][j];
//Grab surface normals
//These are Nx,Ny,Nz due to compiler issues
//float Na = Nx[i][j];
//float Nb = Ny[i][j];
//float Nc = Nz[i][j];
//Do cross product
//float Color = (Na * Lx) + (Nb * Ly) + (Nc * Lz);
//???
//glColor3fv(Color);
//glColor3f(0.5*Color,0.5*Color,0.5*Color);
glColor3f(R[i][j], G[i][j], B[i][j]);
glVertex3f(surfaceX[i][j], surfaceY[i][j], surfaceZ[i][j]);
glColor3f(R[i][j+1], G[i][j+1], B[i][j+1]);
glVertex3f(surfaceX[i][j+1], surfaceY[i][j+1], surfaceZ[i][j+1]);
glColor3f(R[i+1][j+1], G[i+1][j+1], B[i+1][j+1]);
glVertex3f(surfaceX[i+1][j+1], surfaceY[i+1][j+1], surfaceZ[i+1][j+1]);
glColor3f(R[i+1][j], G[i+1][j], B[i+1][j]);
glVertex3f(surfaceX[i+1][j], surfaceY[i+1][j], surfaceZ[i+1][j]);
glEnd();
}
}
//Draw the normals
for (int i = 0; i <= 10; i++)
{
for (int j = 0; j <= 10; j++)
{
glBegin(GL_LINES);
//glColor3f(0.0, 1.0, 1.0);
float length = 1;
glVertex3f(surfaceX[i][j], surfaceY[i][j], surfaceZ[i][j]);
glVertex3f(surfaceX[i][j]+length*Nx[i][j],
surfaceY[i][j]+length*Ny[i][j],
surfaceZ[i][j]+length*Nz[i][j]);
glEnd();
}
}
glEnd();
glFlush();
//Player Cube
//Cube: midx, midy, midz, size
//+Z = Moving TOWARD camera in opengl
//Origin point for reference
glPointSize(10);
glColor3f(1.0, 1.0, 0.0);
glBegin(GL_POINTS);
glVertex3f(0, 0, 0);
glEnd();
//Assign Color of Lines
float R = 1;
float G = 1;
float B = 1;
glBegin(GL_LINES);
glColor3f(R, G, B);
////Drawing the grid
//Vertical lines
for (int i = 0; i < 11; i++)
{
int b = -5 + i;
glVertex3f(b, 0, -5);
glVertex3f(b, 0, 5);
}
//Horizontal lines
for (int i = 0; i < 11; i++)
{
int b = -5 + i;
glVertex3f(-5,0,b);
glVertex3f(5,0,b);
}
glEnd();
glEnd();
glFlush();
}
//---------------------------------------
// Main program
//---------------------------------------
int main(int argc, char *argv[])
{
srand(time(NULL));
//Print Instructions
std::cout << "Project 3 Controls: " << std::endl;
std::cout << "q switches control mode" << std::endl;
std::cout << "w,a,s,d for camera rotation" << std::endl;
//Required
glutInit(&argc, argv);
//Window will default to a different size without
glutInitWindowSize(500, 500);
//Window will default to a different position without
glutInitWindowPosition(250, 250);
//
glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH);
//Required
glutCreateWindow("Project 3");
//Required, calls display function
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
//Required
init();
glutMainLoop();
return 0;
}
既要生成表面和法线，也要生成给定顶点的颜色，我只是不明白为什么它不起作用。