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）：

Pinhole类声明和实现的相关教程结束。