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raytrace.cpp
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raytrace.cpp
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#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#include <limits>
#include <algorithm>
using namespace std;
#include "Raytrace.h"
#include "Scene.h"
bool hitSphere(const ray &r, const sphere &s, float &t);
bool draw(char* outputName, scene &myScene) ;
bool hitPlane(const ray& r, const plane& p, float& t);
bool hitTriangle(const ray& r, const triangle& tr, float& t);
bool hitDisc(const ray& r, const disc& d, float& t);
//whether disc is hit by ray
bool hitDisc(const ray& r, const disc& d, float& t) {
bool retvalue = false;
// whether the plane hit by ray or not
float dist = (d.pos - r.start) * d.normal / (r.dir * d.normal);
point hitpoint = r.start + dist * r.dir;
// whether the hitpoint is in the disc
float r2 = (hitpoint - d.pos) * (hitpoint - d.pos);
if ((dist > 0.1f) && (dist <= t)) {
if (r2 <= d.size * d.size)
{
t = dist;
retvalue = true;
}
}
return retvalue;
}
//whether plane is hit by ray
bool hitPlane(const ray& r, const plane& p, float& t) {
bool retvalue = false;
// The implementation is based on the following equation:
// t = -(N.P + d) / N .D
float dist = (p.pos - r.start) * p.normal / (r.dir * p.normal);
if ((dist > 0.1f) && (dist <= t)) {
t = dist;
retvalue = true;
}
return retvalue;
}
//whether sphere is hit by ray
bool hitSphere(const ray &r, const sphere &s, float &t)
{
vector3d dist = s.pos - r.start;
float B = r.dir * dist;
float D = B*B - dist * dist + s.size * s.size;
// The implementation is based on the following equations:
// a*t2 + b*t + c = 0
// a = D.D = 1, b = 2 * D.P, c = P.P - R * R
if (D < 0.0f)
return false;
float t0 = B - sqrtf(D);
float t1 = B + sqrtf(D);
bool retvalue = false;
if ((t0 > 0.1f) && (t0 <= t))
{
t = t0;
retvalue = true;
}
if ((t1 > 0.1f) && (t1 <= t))
{
t = t1;
retvalue = true;
}
return retvalue;
}
//where triangle is hit by ray
bool hitTriangle(const ray& ray, const triangle& tr, float& tmin)
{
// the implementation is based on the book "raytracing from the ground up" pp.479
float a = tr.v0.x - tr.v1.x, b = tr.v0.x - tr.v2.x, c = ray.dir.x, d = tr.v0.x - ray.start.x;
float e = tr.v0.y - tr.v1.y, f = tr.v0.y - tr.v2.y, g = ray.dir.y, h = tr.v0.y - ray.start.y;
float i = tr.v0.z - tr.v1.z, j = tr.v0.z - tr.v2.z, k = ray.dir.z, l = tr.v0.z - ray.start.z;
float m = f * k - g * j, n = h * k - g * l, p = f * l - h *j;
float q = g * i - e * k, s = e * j - f * i;
float inv_denom = 1.0 / (a * m + b * q + c * s);
float e1 = d * m - b * n - c * p;
float beta = e1 * inv_denom;
if (beta < 0.0) {
return false;
}
float r = e * l - h * i;
float e2 = a * n + d * q + c * r;
float gamma = e2 * inv_denom;
if (gamma < 0.0) {
return false;
}
if (beta + gamma > 1.0) {
return false;
}
float e3 = a * p - b * r + d * s;
float t = e3 * inv_denom;
if (t < 0.1) {
return false;
}
tmin = t;
return true;
}
ray camera_model(float fragmentx, float fragmenty, float depth, vector3d direction, scene &myScene)
{
//move the camera
fragmentx = fragmentx + myScene.cam.vertical;
fragmenty = fragmenty + myScene.cam.horizontal;
depth = depth + myScene.cam.depth;
vector3d rotate = myScene.cam.rotate;
vector3d new_direction = rotate + direction;
ray viewray = {{fragmentx, fragmenty, depth}, new_direction};
return viewray;
}
color addRay(ray viewRay, scene &myScene)
{
color output = {0.0f, 0.0f, 0.0f};
float coef = 1.0f;
int level = 0;
do
{
float t = 2000.0f; //the farthest place I concern
int currentSphere= -1;
int currentPlane = -1;
int currentTriangle = -1;
int currentDisc = -1;
// which object is hit and choose the closet one//
for (unsigned int i = 0; i < myScene.triangleContainer.size(); ++i) {
if (hitTriangle(viewRay, myScene.triangleContainer[i], t)) {
currentTriangle = i;
}
}
for (unsigned int i = 0; i < myScene.sphereContainer.size(); ++i)
{
if (hitSphere(viewRay, myScene.sphereContainer[i], t))
{
currentSphere = i;
currentTriangle = -1;
}
}
for (unsigned int i = 0; i < myScene.planeContainer.size(); ++i) {
if (hitPlane(viewRay, myScene.planeContainer[i], t)) {
currentPlane = i;
currentSphere = -1;
currentTriangle = -1;
}
}
for (unsigned int i = 0; i < myScene.discContainer.size(); ++i) {
if (hitDisc(viewRay, myScene.discContainer[i], t)) {
currentDisc = i;
currentPlane = -1;
currentSphere = -1;
currentTriangle = -1;
}
}
point newStart = viewRay.start + t * viewRay.dir;
//initialize final normal
vector3d n = {0.0, 0.0, 0.0};
material currentMat = {0.0, 0.0, 0.0, 0.0};
//Calculate different vNormal depends on different objects
// Get the material
if (currentSphere != -1) {
n = newStart - myScene.sphereContainer[currentSphere].pos;
float temp = n * n;
if (temp == 0.0f)
break;
temp = 1.0f / sqrtf(temp);
n = temp * n;
currentMat = myScene.materialContainer[myScene.sphereContainer[currentSphere].materialId];
}
else if (currentPlane != -1){
n = myScene.planeContainer[currentPlane].normal;
currentMat = myScene.materialContainer[myScene.planeContainer[currentPlane].materialId];
}
else if (currentDisc != -1){
n = myScene.discContainer[currentDisc].normal;
currentMat = myScene.materialContainer[myScene.discContainer[currentDisc].materialId];
}
else if (currentTriangle != -1) {
n = (myScene.triangleContainer[currentTriangle].v1 - myScene.triangleContainer[currentTriangle].v0) ^ (myScene.triangleContainer[currentTriangle].v2 - myScene.triangleContainer[currentTriangle].v0);
n.x = -n.x;
n.y = -n.y;
n.z = -n.z;
float length = sqrtf(n.x * n.x + n.y * n.y + n.z * n.z);
n.x /= length;
n.y /= length;
n.z /= length;
currentMat = myScene.materialContainer[myScene.triangleContainer[currentTriangle].materialId];
}
//calculate the value at the point of illumination
for (unsigned int j = 0; j < myScene.lightContainer.size(); ++j) {
light currentLight = myScene.lightContainer[j];
vector3d dist = currentLight.pos - newStart;
if (n * dist <= 0.0f)
continue;
float t = sqrtf(dist * dist);
if ( t <= 0.0f )
continue;
ray lightRay;
lightRay.start = newStart;
lightRay.dir = (1/t) * dist;
// computation of the shadows
bool inShadow = false;
for (unsigned int i = 0; i < myScene.sphereContainer.size(); ++i) {
if (hitSphere(lightRay, myScene.sphereContainer[i], t)) {
inShadow = true;
break;
}
}
for (unsigned int i = 0; i < myScene.planeContainer.size(); ++i) {
if (hitPlane(lightRay, myScene.planeContainer[i], t)) {
inShadow = true;
break;
}
}
for (unsigned int i = 0; i < myScene.triangleContainer.size(); ++i) {
if (hitTriangle(lightRay, myScene.triangleContainer[i], t)) {
inShadow = true;
break;
}
}
for (unsigned int i = 0; i < myScene.discContainer.size(); ++i) {
if (hitDisc(lightRay, myScene.discContainer[i], t)) {
inShadow = true;
break;
}
}
if (!inShadow) {
//lambert
float lambert = (lightRay.dir * n) * coef;
output.red += lambert * currentLight.intensity.red * currentMat.red;
output.green += lambert * currentLight.intensity.green * currentMat.green;
output.blue += lambert * currentLight.intensity.blue * currentMat.blue;
if (currentMat.mode == 2)
{
//Phong
float reflet = 2.0f * (lightRay.dir * n);
vector3d phongDir = lightRay.dir - reflet * n;
float phongTerm = max(phongDir * viewRay.dir, 0.0f) ;
phongTerm = currentMat.specular * powf(phongTerm, 60) * coef;
output.red += phongTerm * currentLight.intensity.red;
output.green += phongTerm * currentLight.intensity.green;
output.blue += phongTerm * currentLight.intensity.blue;
}
else if (currentMat.mode == 1){
//Blinn
float fViewProjection = viewRay.dir * n;
vector3d blinnDir = lightRay.dir - viewRay.dir;
float fLightProjection = lightRay.dir * n;
float temp = blinnDir * blinnDir;
if (temp != 0.0f )
{
float blinn = invsqrtf(temp) * max(fLightProjection - fViewProjection , 0.0f);
blinn = coef * powf(blinn, currentMat.power);
output.red += blinn *currentMat.specular * currentLight.intensity.red;
output.green += blinn *currentMat.specular * currentLight.intensity.green;
output.blue += blinn *currentMat.specular * currentLight.intensity.blue;
}
}
}
}
//compute the reflection
coef *= currentMat.reflection;
float reflet = 2.0f * (viewRay.dir * n);
viewRay.start = newStart;
viewRay.dir = viewRay.dir - reflet * n;
level++;
}
while ((coef > 0.0f) && (level < 15));
return output;
}
bool draw(char* outputName, scene &myScene)
{
ofstream imageFile(outputName,ios_base::binary);
if (!imageFile)
return false;
imageFile.put(0).put(0);
imageFile.put(2);
imageFile.put(0).put(0);
imageFile.put(0).put(0);
imageFile.put(0);
imageFile.put(0).put(0);
imageFile.put(0).put(0);
imageFile.put((unsigned char)(myScene.sizex & 0x00FF)).put((unsigned char)((myScene.sizex & 0xFF00) / 256));
imageFile.put((unsigned char)(myScene.sizey & 0x00FF)).put((unsigned char)((myScene.sizey & 0xFF00) / 256));
imageFile.put(24);
imageFile.put(0);
for (int y = 0; y < myScene.sizey; ++y) {
for (int x = 0; x < myScene.sizex; ++x) {
//color values
float red = 0, green = 0, blue = 0;
float coef = 1.0f;
//depth of reflection
int level = 0;
float depth = -500.0f;
vector3d direction = {0.0f, 0.0f, 1.0f};
ray viewRay = camera_model((float)x, (float)y, depth, direction, myScene);
color temp = addRay (viewRay, myScene);
imageFile.put((unsigned char)min(temp.blue*255.0f,255.0f))
.put((unsigned char)min(temp.green*255.0f, 255.0f))
.put((unsigned char)min(temp.red*255.0f, 255.0f));
}
}
return true;
}
int main(int argc, char* argv[])
{
if (argc < 3)
{
cout << "Usage : Raytrace.exe Scene.txt Output.tga" << endl;
return -1;
}
scene myScene;
if (!init(argv[1], myScene))
{
cout << "Failure when reading the Scene file." << endl;
return -1;
}
if (!draw(argv[2], myScene))
{
cout << "Failure when creating the image file." << endl;
return -1;
}
return 0;
}