flaschenray/camera.cpp

#include "camera.hpp"
#include <Eigen/Dense>
#include "warping.hpp"
std::vector<Eigen::Vector3f> camera::get_image(const scene& sc, size_t n, sampler _rng)const{
    using namespace Eigen;
    std::vector<Eigen::Vector3f> img(n * n, Eigen::Vector3f(0,0,0));
    const Eigen::Vector3f lookray = (look_at - pos).normalized();
	const Eigen::Vector3f left = lookray.cross(up).normalized();
	const Eigen::Vector3f realup = left.cross(lookray);
    const int n2 = n / 2;
    size_t raycasts = 0;
    #pragma omp parallel
    {
    sampler rng;
    std::uniform_real_distribution<float> pert_dis(-0.5,0.5);
    #pragma omp for collapse(2) schedule(guided) reduction(+:raycasts)
    for(int j = 0;j < n;j++){
		for(int i = 0;i < n;i++){
            
            Eigen::Vector3d accum(0,0,0);
            
            for(size_t smp = 0;smp < 4096;smp++){
                Eigen::Vector3f di = lookray + (left * ((pert_dis(rng.m_rng) + float(i - n2)) / n2 / 1.5)) + realup * ((pert_dis(rng.m_rng) + float(j - n2)) / n2 / 1.5);
                di.normalize();
                struct RTCRayHit rayhit;
                rayhit.ray.org_x = pos.x();
                rayhit.ray.org_y = pos.y();
                rayhit.ray.org_z = pos.z();
                rayhit.ray.dir_x = di.x();
                rayhit.ray.dir_y = di.y();
                rayhit.ray.dir_z = di.z();
                Vector3f hitpos = pos;
                Vector3f transport(1,1,1);
                for(size_t bounces = 0;bounces < 5;bounces++){
                    struct RTCIntersectContext context;
                    rtcInitIntersectContext(&context);
                    rayhit.ray.tnear = 0.00002f;
                    rayhit.ray.tfar = std::numeric_limits<float>::infinity();
                    rayhit.ray.mask = -1;
                    rayhit.ray.flags = 0;
                    rayhit.hit.geomID = RTC_INVALID_GEOMETRY_ID;
                    rayhit.hit.instID[0] = RTC_INVALID_GEOMETRY_ID;
                    rtcIntersect1(sc.m_scene, &context, &rayhit);
                    raycasts++;
                    if(rayhit.hit.geomID != RTC_INVALID_GEOMETRY_ID){
                        if(sc.emitters.contains(rayhit.hit.geomID)){
                            accum += (Eigen::Vector3d(0,1,1).array() * transport.cast<double>().array()).matrix();
                            //std::cout << "sd" << std::endl;
                            goto inner;
                        }
                        //std::cout << std::to_string(rayhit.ray.tfar) + "\n";
                        rayhit.ray.org_x += rayhit.ray.dir_x * rayhit.ray.tfar;
                        rayhit.ray.org_y += rayhit.ray.dir_y * rayhit.ray.tfar;
                        rayhit.ray.org_z += rayhit.ray.dir_z * rayhit.ray.tfar;
                        Vector3f hitnormal = Vector3f(rayhit.hit.Ng_x, rayhit.hit.Ng_y, rayhit.hit.Ng_z).normalized();
                        //std::cout << hitnormal << "\n\n";
                        //Vector3f newdir = cosine_hemisphere(hitnormal, rng.next2D()).normalized();
                        Vector3f newdir = uniform_sphere(rng.next2D());
                        if(newdir.dot(hitnormal) <= 0){
                            newdir *= -1.0f;
                        }
                        transport *= newdir.dot(hitnormal);
                        //std::cout << std::to_string(newdir.dot(Vector3f(rayhit.hit.Ng_x, rayhit.hit.Ng_y, rayhit.hit.Ng_z).normalized())) + std::string("\n");
                        rayhit.ray.dir_x = newdir.x();
                        rayhit.ray.dir_y = newdir.y();
                        rayhit.ray.dir_z = newdir.z();
                    }
                    else{
                        goto inner;
                    }
                }
                inner:
                (void)0;
            }
            img[j * n + i] = (accum.cast<float>() / 512.0f).array().pow(0.6f).matrix();
        }
    }
    }
    std::cout << std::to_string(raycasts) + " Raycasts\n";
    return img;
}

camera::camera(const Eigen::Vector3f& loc, const Eigen::Vector3f& look, const Eigen::Vector3f& u) : pos(loc), look_at(look), up(u){
	
}