diff options
Diffstat (limited to 'viewport.h')
| -rw-r--r-- | viewport.h | 51 |
1 files changed, 45 insertions, 6 deletions
@@ -42,6 +42,33 @@ public: } }; +// Generate a circle of confusion of circle shape. (can be extended to any shape in the future) +class bokeh_ctx { + bool enabled; + std::mt19937_64 mt; + std::uniform_real_distribution<double> uni{-1.0, 1.0}; + +public: + bokeh_ctx() : enabled{false} {} + + bokeh_ctx(uint64_t seed) : enabled{true}, mt{seed} {} + + void operator()(double &x, double &y) { + if (!enabled) { + x = 0; + y = 0; + return; + } + double x_, y_; + do { + x_ = uni(mt); + y_ = uni(mt); + } while (x_ * x_ + y_ * y_ >= 1); + x = x_; + y = y_; + } +}; + // TODO rename to camera // Single sampled viewport which supports bias sampling // U: color depth, V: pos @@ -59,6 +86,8 @@ class basic_viewport { // double focus_length; // distance between the focus point and the image screen hitlist &world; vec3<V> vup{0, 1, 0}; // vector determine the camera rotating + double aperture; // radius ratio of the aperture + double focus_dist; inline void check_vup() const { // vup must not be parallel with screen_center-cxyz @@ -69,22 +98,25 @@ public: basic_viewport(const vec3<V> &cxyz, const vec3<V> &screen_center, uint32_t image_width, uint32_t image_height, - double fov_h, hitlist &world) : + double fov_h, double aperture, double focus_dist, hitlist &world) : cxyz{cxyz}, screen_center{screen_center}, image_width{image_width}, image_height{image_height}, screen_hw{(cxyz - screen_center).norm() * tan((double) fov_h / 2.0)}, screen_hh{screen_hw * ((double) image_height / image_width)}, - world{world} { + world{world}, + aperture{aperture}, focus_dist{focus_dist} { check_vup(); } basic_viewport(const vec3<V> &cxyz, const vec3<V> &screen_center, uint32_t image_width, uint32_t image_height, double screen_hw, double screen_hh, + double aperture, double focus_dist, hitlist &world) : cxyz{cxyz}, screen_center{screen_center}, image_width{image_width}, image_height{image_height}, screen_hw{screen_hw}, screen_hh{screen_hh}, - world{world} { + world{world}, + aperture{aperture}, focus_dist{focus_dist} { assert(std::abs(1.0 * image_width / image_height - 1.0 * screen_hw / screen_hh) < 1e-8); check_vup(); } @@ -95,7 +127,7 @@ public: * @param by bias on y axis (0.0 <= by < 1.0) * @return */ - bitmap<U> render(uint64_t diffuse_seed, bias_ctx &bias + bitmap<U> render(uint64_t diffuse_seed, bias_ctx &bias, bokeh_ctx &bokeh /* by putting thread-specific parameters in call argument list, make users convenient*/) const { // The implementation keep all mutable state in local stack, // keeping the class immutable and thread-safe. @@ -106,10 +138,12 @@ public: const int img_hw = image_width / 2, img_hh = image_height / 2; // screen plane is determined by coord system x`Vy`, where V is screen_center // for variable name we let u := x`, v := y` - const auto u = cross(r, vup).unit_vec() * screen_hw, v = cross(u, r).unit_vec() * screen_hh; + const auto u0 = cross(r, vup).unit_vec(), v0 = cross(u0, r).unit_vec(); + const auto u = u0 * screen_hw, v = v0 * screen_hh; assert(dot(r, u) < 1e-8); assert(dot(r, v) < 1e-8); assert(dot(u, v) < 1e-8); + const V pof_scale = (V) 1.0 + (V) focus_dist / r.norm(); // iterate over every pixel on the image for (int j = -img_hh + 1; j <= img_hh; ++j) { // axis y, transformation is needed for (int i = -img_hw; i < img_hw; ++i) { // axis x @@ -122,7 +156,12 @@ public: const auto off_v = (1.0 * j + by) / img_hh; const auto off = off_u * u + off_v * v; // offset on screen plane const auto dir = r + off; // direction vector from camera to current pixel on screen - ray3d ray{cxyz, dir}; // from camera to pixel (on the viewport) + const auto dir_pof = dir * pof_scale; // difference from camera to point on focus plane + const auto pof = cxyz + dir_pof; // point on focus plane, the destination + double bokeh_u, bokeh_v; + bokeh(bokeh_u, bokeh_v); + const auto source = cxyz + (aperture * bokeh_u) * u0 + (aperture * bokeh_v) * v0; + ray3d ray{source, pof - source}; // from camera to pixel (on the viewport) const auto pixel = world.color<U>(ray, ruvg); const auto x_ = i + img_hw, y_ = -j + img_hh; image.set(x_, y_, pixel); |