Scene Management

Scene configuration and preset scenes.

Scene

Scene container managing geometry on GPU.

class Scene {
public:
    Scene();
    ~Scene();

    // Add primitives
    void add_sphere(const Sphere& sphere);
    void add_plane(const Plane& plane);
    void add_material(const Material& material);
    void add_light(const PointLight& light);

    // Build acceleration structure
    void build_bvh();

    // GPU intersection
    __device__ bool intersect(const ray& r, HitRecord& rec) const;
    __device__ bool intersect_any(const ray& r, float t_max) const;  // Shadow ray

    // Clear scene
    void clear();

private:
    Sphere* d_spheres_;
    Plane* d_planes_;
    Material* d_materials_;
    PointLight* d_lights_;
    BVHNode* d_bvh_nodes_;
    int num_spheres_, num_planes_, num_materials_, num_lights_;
};

SceneBuilder

Helper class for constructing scenes.

class SceneBuilder {
public:
    SceneBuilder& with_sphere(const vec3& center, float radius, int material_id);
    SceneBuilder& with_plane(const vec3& point, const vec3& normal, int material_id);
    SceneBuilder& with_material(const Material& material);
    SceneBuilder& with_light(const vec3& position, const vec3& color);

    Scene build();
};

Preset Scenes

// Demo scene: 8 spheres + ground plane, multiple materials, 3 lights
Scene create_demo_scene();

// Cornell box: 6 walls as planes, 2 spheres, 1 light
Scene create_cornell_box();

// Random spheres: procedurally generated ~100 spheres
Scene create_random_scene(int num_spheres = 100);

PointLight

Light source definition.

struct PointLight {
    vec3 position;
    vec3 color;
    float intensity;
};

Usage Example

// Using preset
Scene scene = create_demo_scene();
scene.build_bvh();

// Custom scene
SceneBuilder builder;
builder
    .with_material(Material::matte(vec3(0.8f, 0.2f, 0.2f)))
    .with_sphere(vec3(0, 0, 0), 1.0f, 0)
    .with_light(vec3(5, 5, 5), vec3(1, 1, 1));
Scene custom_scene = builder.build();

// Render
Renderer renderer(800, 600);
renderer.set_scene(scene);
renderer.set_mode(RenderMode::Phong);
renderer.render();
renderer.save_ppm("output.ppm");

Scene File Format (Planned)

{
  "spheres": [
    {"center": [0, 0, 0], "radius": 1.0, "material": 0}
  ],
  "materials": [
    {"type": "matte", "albedo": [0.8, 0.2, 0.2]}
  ],
  "lights": [
    {"position": [5, 5, 5], "color": [1, 1, 1]}
  ]
}