- Implementation of the classical recursive ray-tracing algorithm (in pseudo-code):
#define MAX_RAY_DEPTH 3
color Trace(const Ray &ray, int depth)
{
Object *object = NULL;
float minDist = INFINITY;
Point pHit;
Normal nHit;
for (int k = 0; k < objects.size(); ++k) {
if (Intersect(objects[k], ray, &pHit, &nHit)) {
// ray origin = eye position of it's the prim ray
float distance = Distance(ray.origin, pHit);
if (distance < minDistance) {
object = objects[i];
}
}
}
if (object == NULL)
return 0;
// if the object material is glass, split the ray into a reflection
// and a refraction ray.
if (object->isGlass && depth < MAX_RAY_DEPTH) {
// compute reflection
Ray reflectionRay;
reflectionRay = computeReflectionRay(ray.direction, nHit);
// recurse
color reflectionColor = Trace(reflectionRay, depth + 1);
Ray refractioRay;
refractionRay = computeRefractionRay(
object->indexOfRefraction,
ray.direction,
nHit);
// recurse
color refractionColor = Trace(refractionRay, depth + 1);
float Kr, Kt;
fresnel(
object->indexOfRefraction,
nHit,
ray.direction,
&Kr,
&Kt);
return reflectionColor * Kr + refractionColor * (1-Kr);
}
// object is a diffuse opaque object
// compute illumination
Ray shadowRay;
shadowRay.direction = lightPosition - pHit;
bool isShadow = false;
for (int k = 0; k < objects.size(); ++k) {
if (Intersect(objects[k], shadowRay)) {
// hit point is in shadow so just return
return 0;
}
}
// point is illuminated
return object->color * light.brightness;
}
for (int j = 0; j < imageHeight; ++j) {
for (int i = 0; i < imageWidth; ++i) {
// compute primary ray direction
Ray primRay;
computePrimRay(i, j, &primRay);
pixels[i][j] = Trace(primRay, 0);
}
}
- I'm having a little confusion when using gdb. When stepping through phase_2, and when I'm in read_six_numbers function, I cannot use "x/s $eax", it says "<Address <0xaddr> out of bounds>".
How can i see what's in eax?
- If you want to see what %eax has in it, you need to use the command "print".
"x" is for when you know that %eax has an address in it and you want to go to that address.
C++ Vector Class - GameDev.Net Discussion Forums
- #ifndef _VECTOR
#define _VECTOR
#include <math.h>
class Vector3D
{
private:
float x, y, z;
public:
//default constructor
Vector3D(float X = 0, float Y = 0, float Z = 0)
{
x = X;
y = Y;
z = Z;
}
~Vector3D(){};
//calculate and return the magnitude of this vector
float GetMagnitude()
{
return sqrtf(x * x + y * y + z * z);
}
//multiply this vector by a scalar
Vector3D operator*(float num) const
{
return Vector3D(x * num, y * num, z * num);
}
//pass in a vector, pass in a scalar, return the product
friend Vector3D operator*(float num, Vector3D const &vec)
{
return Vector3D(vec.x * num, vec.y * num, vec.z * num);
}
//add two vectors
Vector3D operator+(const Vector3D &vec) const
{
return Vector3D(x + vec.x, y + vec.y, z + vec.z);
}
//subtract two vectors
Vector3D operator-(const Vector3D &vec) const
{
return Vector3D(x - vec.x, y - vec.y, z - vec.z);
}
//normalize this vector
void normalizeVector3D()
{
float magnitude = sqrtf(x * x + y * y + z * z);
x /= magnitude;
y /= magnitude;
z /= magnitude;
}
//calculate and return dot product
float dotVector3D(const Vector3D &vec) const
{
return x * vec.x + y * vec.y + z * vec.z;
}
//calculate and return cross product
Vector3D crossVector3D(const Vector3D &vec) const
{
return Vector3D(y * vec.z - z * vec.y,
z * vec.x - x * vec.z,
x * vec.y - y * vec.x);
}
};
#endif - In my code, I have dot and cross as free functions. But that is just how I choose to do it.
- what is a free function?
- One not in a class. For example, I have:
float dot(const Vector &one, const Vector &two )
{
return /* ... */;
}
Vector cross(const Vector &one, const Vector &two )
{
return /* ... */;
}
// usage:
void example()
{
Vector3 one, two;
float d = dot(one,two);
Vector3 c = cross(two,one);
}
A raytracer in C++ - Part I - First rays
We have to cast a ray, at each one of our pixel to determine its color. This translates as the following C code :
for (int y = 0; y < myScene.sizey; ++y) {
for (int x = 0; x < myScene.sizex; ++x) {
// ...
}
}
- Z:\Microsoft Visual Studio 9.0\VC\INCLUDE\cstdio(39) : error C2143: syntax error
: missing '{' before ':'
Z:\Microsoft Visual Studio 9.0\VC\INCLUDE\cstdio(39) : error C2059: syntax error
: ':' You have given the program an extension of .c which
means the compiler will try to compile it according to
the rules of the C language. But it uses C++ features.Either change the extension to .cpp or compile with the option /TP
error C2381: 'exit' : redefinition; __declspec(noreturn) differs
"There is an incompatibility between glut.h and Visual Studio .NET. that results in compile errors: error C2381: 'exit' : redefinition; __declspec(noreturn) differs
error C3861: 'exit': identifier not found, even with argument-dependent lookupTo fix the error, right click on the project name in the Solution Explorer tab and select Properties -> C/C++ -> Preprocessor -> Preprocessor definitions and append GLUT_BUILDING_LIB to the existing definitions, seperated by semicolons. "
How do I disable deprecation in VC++ Express Edition?
- How/where do I use _CRT_SECURE_NO_WARNINGS ?
- Project properties->Configuration Properties->C/C++->Preprocessor->Preprocessor Definitions
Click on the elipses (...)
type any definitions you like separated by "\n"ie
_CRT_SECURE_NO_WARNINGS
hit OK.
Posted from Diigo. The rest of my favorite links are here.
