I'm writing a simple ray-tracer (it was meant to be a one day project but now I'm stumped) that will simply draw the silhouette of the objects in the scene.
Now, I've read around a bit and found out how to generate the eye rays, but there seems to be a few different methods. I'm trying the following (using pixelToaster to get the pixels on screen);
#include "PixelToaster.h"
#include "RTSphere.h"
#include <Ray.h>
#include <limits>
using namespace PixelToaster;
void clear(vector<TrueColorPixel> ℑ, TrueColorPixel &color)
int main(int argc, char *argv[])
{
const int width = 800;
const int height = 600;
Display display("Ray Tracer", width, height, Output::Default, Mode::TrueColor);
vector<TrueColorPixel> pixels(width * height);
clear(pixels, TrueColorPixel(0, 0, 255));
float fovW = toRadians(45.0f);
float fovH = (float)height / (float)width * fovW;
float tanFovW = tan(fovW);
float tanFovH = tan(fovH);
float zNear = -1.0f;
float zFar = -1000.0f;
Vector3f camPos(0.0f, 0.0f, 0.0f);
Vector3f lookAt(0.0f, 0.0f, zNear);
lookAt.normaliseSelf();
RTSphere sphere(0.5f, Vector3f(0.0f, 0.0f, -5.0f));
//Perform raytracing.
unsigned int index = 0;
for(int v = 0; v < height; ++v)
{
for(int u = 0; u < width; ++u)
{
Vector3f target(lookAt);
float x = ((2.0f * (float)u) - (float)width) / (float)width * tanFovW;
float y = ((2.0f * (float)v) - (float)height) / (float)height * tanFovH;
target = Vector3f(x, y, zNear);
target.normaliseSelf();
Rayf ray(camPos, target);
float result = sphere.intersect(ray);
if(result < zFar)
{
pixels[index].r = 255;
pixels[index].b = pixels[index].g = pixels[index].r;
}
++index;
}
}
while(display.open())
{
display.update(pixels);
}
return 0;
}
void clear(vector<TrueColorPixel> ℑ, TrueColorPixel &color)
{
vector<TrueColorPixel>::iterator it = image.begin();
while(it != image.end())
{
*it = color;
++it;
}
}
but that gives me a solid black screen for output.
I've tried putting the x, y, and z direction of the eye rays into the pixel r, g, b values, which gives me these:
ray X direction:
ray Y direction:
ray Z direction:
ray XYZ direction:
So what there is wrong exactly? I dunno about you but that doesn't look right to me :P
I haven't discounted the fact that I may also have something wrong with my ray-sphere intersection code, so here's that as well;
float RTSphere::intersect(const Rayf &ray)
{
Vector3f delta = ray.mPos - mPos;
float A = delta.dot(ray.mDir);
float B = delta.dot(delta) - mRadius * mRadius;
float C = A * A - B;
return C > 0 ? (-A - sqrt(C)) : std::numeric_limits<float>::infinity();
}
Any ideas?
[Edited by - _Sauce_ on October 27, 2009 3:42:34 AM]
ray Y direction:
ray Z direction:
ray XYZ direction:
So what there is wrong exactly? I dunno about you but that doesn't look right to me :P
I haven't discounted the fact that I may also have something wrong with my ray-sphere intersection code, so here's that as well;
