Pinhole类声明和实现

针孔相机，带旋转，移动等功能。

类声明：

#pragma once
#ifndef __PINHOLE_HEADER__
#define __PINHOLE_HEADER__

#include "camera.h"

class Pinhole :public Camera {
public:
	Pinhole();
	~Pinhole();
	Pinhole(const Pinhole& ph);
	void set_view_distance(const ldouble a);
	void set_zoom(const ldouble factor);
	void set_angle(const ldouble deg);
	Vector3 ray_direction(const Point3& p) const;
	virtual Camera* clone() const;
	virtual void render_scene(World& w);
	Pinhole& operator=(const Pinhole& ph);
private:
	ldouble d, zoom;
};
#endif

类实现：

#include "pch.h"
#include "pinhole.h"
#include "../utilities/world.h"
#include "../utilities/viewplane.h"
#include "../samplers/sampler.h"
#include "../tracers/tracer.h"

Pinhole::Pinhole() :Camera(), d(1), zoom(1) {}

Pinhole::Pinhole(const Pinhole& ph) : Camera(ph), d(ph.d), zoom(ph.zoom) {}

Pinhole::~Pinhole() {}

void Pinhole::set_view_distance(const ldouble a) {
	d = a;
}

void Pinhole::set_zoom(const ldouble factor) {
	zoom = factor;
}

void Pinhole::set_angle(const ldouble deg) {
	ldouble rad = radian(deg);
	up = Point3(std::cos(rad) * up.x - std::sin(rad) * up.y,
		std::sin(rad) * up.x + std::cos(rad) * up.y, up.z);//绕z轴旋转
}

Vector3 Pinhole::ray_direction(const Point3& p) const{
	Vector3 dir = p.x * u + p.y * v - w / d;//书中这里是错误的
	dir.normalize();
	return dir;
}

Camera* Pinhole::clone() const {
	return new Pinhole(*this);
}

void Pinhole::render_scene(World& w) {
	ViewPlane vp(w.vp);
	Ray ray;
	integer depth = 0;
	Point3 sp, pp;
	w.open_window(vp.hres, vp.vres);
	vp.s = 1 / (zoom * vp.s);
	ray.o = eye;
	for (integer r = vp.vres - 1; r >= 0; r--)//render from left-corner to right-corner
		for (integer c = 0; c < vp.hres; c++) {
			RGBColor color;
			for (integer p = 0; p < vp.nsamples; p++) {
				sp = vp.sampler->sample_unit_square();
				pp.x = (c - 0.5 * vp.hres + sp.x) * vp.s;
				pp.y = (r - 0.5 * vp.vres + sp.y) * vp.s;
				ray.d = ray_direction(pp);
				color += w.tracer_ptr->trace_ray(ray);
			}
			color /= vp.nsamples;
			color *= exposure_time;
			w.display_pixel(r, c, color);
		}
}

Pinhole& Pinhole::operator=(const Pinhole& ph) {
	if (this == &ph)
		return *this;
	Camera::operator= (ph);
	d = ph.d;
	zoom = ph.zoom;
	return *this;
}

需要修改的World类：

class World {
public:
	World();
	World(const World& wr);
	~World();
	void build();
	void render();
	...
	void open_window(const integer hres, const integer vres);
	void display_pixel(const integer row, const integer column, const RGBColor& color);
	void set_camera(Camera* const cam_ptr);//新加
	ViewPlane vp;
	Tracer* tracer_ptr;
private:
	std::stringstream ss;
	std::vector<Geometrics*> objects;
	RGBColor backgrd_color;
	Camera* camera_ptr;//新加
};

　　

实现代码修改：

void World::build() {
	vp.set_hres(200);
	vp.set_vres(100);
	vp.set_sampler(new Hammersley());
	vp.sampler->map_to_sphere();
	tracer_ptr = new MultiSphere(this);
	Geometrics* obj = new Sphere(0, 0.5);
	obj->set_color(RGBColor(1, 0, 0));
	add_object(obj);
	obj = new Sphere(Point3(0, -100.5, 0), 100);
	obj->set_color(RGBColor(0, 0, 1));
	add_object(obj);
	Pinhole* pinhole = new Pinhole();
	pinhole->set_eye(Point3(0, 0, 1));
	pinhole->set_lookat(Point3(0));
	pinhole->set_view_distance(1.5);//视距测试
	pinhole->set_angle(-45);//旋转测试
	//pinhole->set_zoom(2.0);//缩放测试
	pinhole->compute_uvw();
	set_camera(pinhole);
}

void World::render() {
	camera_ptr->render_scene(*this);
}

　　

测试效果图（左旋转45度图）：