tuto_bvh2.cpp File Reference

bvh 2 niveaux et instances More...

#include <algorithm>
#include <vector>
#include <cfloat>
#include "vec.h"
#include "mat.h"
#include "color.h"
#include "image.h"
#include "image_io.h"
#include "orbiter.h"
#include "mesh.h"
#include "wavefront.h"

Go to the source code of this file.

Classes
struct	Ray
	rayon. More...
struct	Hit
	intersection avec un triangle. More...
struct	BBoxHit
	intersection avec une boite / un englobant. More...
struct	BBox
	boite englobante. More...
struct	Node
	construction de l'arbre / BVH. More...
struct	BVHT< T >
	bvh parametre par le type des primitives, cf triangle et instance... More...
struct	Triangle
	triangle pour le bvh, cf fonction bounds() et intersect(). More...
struct	Instance
	instance pour le bvh, cf fonctions bounds() et intersect(). More...

Typedefs
typedef BVHT< Triangle >	BVH
typedef BVHT< Triangle >	BLAS
typedef BVHT< Instance >	TLAS

Functions
Node	make_node (const BBox &bounds, const int left, const int right)
Node	make_leaf (const BBox &bounds, const int begin, const int end)
int	main (int argc, char **argv)

Detailed Description

bvh 2 niveaux et instances

Definition in file tuto_bvh2.cpp.

Typedef Documentation

BVH

typedef BVHT<Triangle> BVH

Definition at line 297 of file tuto_bvh2.cpp.

BLAS

typedef BVHT<Triangle> BLAS

Definition at line 298 of file tuto_bvh2.cpp.

TLAS

typedef BVHT<Instance> TLAS

Definition at line 352 of file tuto_bvh2.cpp.

Function Documentation

make_node()

Node make_node	(	const BBox &	bounds,
		const int	left,
		const int	right )

Definition at line 109 of file tuto_bvh2.cpp.

{
    Node node { bounds, left, right };
    assert(node.internal());    // verifie que c'est bien un noeud...
    return node;
}

make_leaf()

Node make_leaf	(	const BBox &	bounds,
		const int	begin,
		const int	end )

Definition at line 117 of file tuto_bvh2.cpp.

{
    Node node { bounds, -begin, -end };
    assert(node.leaf());        // verifie que c'est bien une feuille...
    return node;
}

main()

int main	(	int	argc,
		char **	argv )

Definition at line 355 of file tuto_bvh2.cpp.

{
    const char *mesh_filename= "data/robot.obj";
    const char *orbiter_filename= nullptr;
    
    if(argc > 1) mesh_filename= argv[1];
    if(argc > 2) orbiter_filename= argv[2];
    
    Mesh mesh= read_mesh(mesh_filename);
    if(mesh.triangle_count() == 0)
        return 1;
    
    BBox mesh_bounds;
    mesh.bounds(mesh_bounds.pmin, mesh_bounds.pmax);
    
    // construit le bvh de l'objet
    BVH bvh;
    {
        // recupere les triangles du mesh
        std::vector<Triangle> triangles;
        for(int i= 0; i <mesh.triangle_count(); i++)
        {
            TriangleData data= mesh.triangle(i);
            triangles.push_back( Triangle(data, triangles.size()) );
        }
        
        // construit le bvh...
        bvh.build(triangles);
    }
    
    // instancie l'objet
    TLAS top_bvh;
    {
        std::vector<Instance> instances;
        for(int i= -2; i <= 2; i++)
        {
            Transform model= Translation(i*10, 0, 0);
            instances.push_back( Instance(mesh_bounds, model, bvh, instances.size()) );
        }
        
        // construit le bvh...
        top_bvh.build(instances);
    }
    
    // regle la camera
    Orbiter camera;
    if(orbiter_filename == nullptr || camera.read_orbiter(orbiter_filename) < 0)
        // les objets sont instancies sur une ligne, agrandir la zone observee par la camera...
        camera.lookat(mesh_bounds.pmin * 5, mesh_bounds.pmax * 5);      
    
    // image resultat
    Image image(1024, 640);
    
    // transformations
    Transform model= Identity();
    Transform view= camera.view();
    Transform projection= camera.projection();
    Transform viewport= Viewport(image.width(), image.height());
    Transform inv= Inverse(viewport * projection * view * model);
    
    // calcule l'image en parallele avec openMP
#pragma omp parallel for 
    for(unsigned y= 0; y < image.height(); y++)
    for(unsigned x= 0; x < image.width(); x++)
    {
        // genere le rayon pour le pixel x,y
        Point o= inv( Point(x, y, 0) ); // origine
        Point e= inv( Point(x, y, 1) ); // extremite
        Ray ray(o, e);
        
        // intersections !
        if(Hit hit= top_bvh.intersect(ray))
            image(x, y)= Red(); // touche ! 
    }
    
    write_image(image, "render.png");
    return 0;
}