hw3和hw2在rasterize_triangle函数上的区别是需要自己计算插值
void rst::rasterizer::rasterize_triangle(const Triangle& t, const std::array<Eigen::Vector3f, 3>& view_pos)
{
auto v = t.toVector4();
int minx = INT_MAX;
int maxx = INT_MIN;
int miny = INT_MAX;
int maxy = INT_MIN;
for(auto& i : v)
{
minx = i.x() < minx ? i.x() : minx;
miny = i.y() < miny ? i.y() : miny;
maxx = i.x() > maxx ? i.x() : maxx;
maxy = i.y() > maxy ? i.y() : maxy;
}
for(int i = minx; i <= maxx; i++)
{
for(int j = miny; j <= maxy; j++)
{
float x = i + 0.5f;
float y = j + 0.5f;
if(insideTriangle(x, y, t.v))
{
auto[alpha, beta, gamma] = computeBarycentric2D(x, y, t.v);
float Z = 1.0 / (alpha / v[0].w() + beta / v[1].w() + gamma/v[2].w());
float zp = alpha * v[0].z() / v[0].w() + beta * v[1].z() / v[1].w() + gamma * v[2].z() / v[2].w();
zp *= Z;
int index = get_index(i, j);
if(zp < depth_buf[index])
{
auto interpolated_color = interpolate(alpha, beta, gamma, t.color[0], t.color[1], t.color[2], 1);
auto interpolated_normal = interpolate(alpha, beta, gamma, t.normal[0], t.normal[1], t.normal[2], 1).normalized();
auto interpolated_texcoords = interpolate(alpha, beta, gamma, t.tex_coords[0], t.tex_coords[1], t.tex_coords[2], 1);
auto interpolated_shadingcoords = interpolate(alpha, beta, gamma, view_pos[0], view_pos[1], view_pos[2], 1);
fragment_shader_payload payload(interpolated_color, interpolated_normal.normalized(), interpolated_texcoords, texture ? &*texture : nullptr);
payload.view_pos = interpolated_shadingcoords;
depth_buf[index] = zp;
auto pixel_color = fragment_shader(payload);
set_pixel(Eigen::Vector2i(i, j), pixel_color);
}
}
}
}
}完成后就可以得到
Blinn-Phong模型的公式
Eigen::Vector3f phong_fragment_shader(const fragment_shader_payload& payload)
{
Eigen::Vector3f ka = Eigen::Vector3f(0.005, 0.005, 0.005);
Eigen::Vector3f kd = payload.color;
Eigen::Vector3f ks = Eigen::Vector3f(0.7937, 0.7937, 0.7937);
auto l1 = light{{20, 20, 20}, {500, 500, 500}};
auto l2 = light{{-20, 20, 0}, {500, 500, 500}};
std::vector<light> lights = {l1, l2};
Eigen::Vector3f amb_light_intensity{10, 10, 10};
Eigen::Vector3f eye_pos{0, 0, 10};
float p = 150;
Eigen::Vector3f color = payload.color;
Eigen::Vector3f point = payload.view_pos;
Eigen::Vector3f normal = payload.normal;
Eigen::Vector3f result_color = {0, 0, 0};
for (auto& light : lights)
{
Eigen::Vector3f light_direction = (light.position - point).normalized();
Eigen::Vector3f view_direction = (eye_pos - point).normalized();
Eigen::Vector3f half_vector = (light_direction + view_direction).normalized();
float reflection_intensity = std::max(0.0f, half_vector.dot(normal));
float light_intensity_attenuation = (light.position - point).dot(light.position - point);
Eigen::Vector3f diffuse_reflection = kd.cwiseProduct(light.intensity / light_intensity_attenuation);
diffuse_reflection *= reflection_intensity;
Eigen::Vector3f high_lights = ks.cwiseProduct(light.intensity / light_intensity_attenuation);
high_lights *= std::pow(reflection_intensity, p);
result_color += (diffuse_reflection + high_lights);
}
Eigen::Vector3f ambient_light_reflection = ka.cwiseProduct(amb_light_intensity);
result_color += ambient_light_reflection;
return result_color * 255.f;
}就可以得到
按题目的要求，将纹理颜色视为公式中的kd
Eigen::Vector3f texture_fragment_shader(const fragment_shader_payload& payload)
{
Eigen::Vector3f return_color = {0, 0, 0};
if (payload.texture)
{
return_color = payload.texture->getColor(payload.tex_coords.x(), payload.tex_coords.y());
}
Eigen::Vector3f texture_color;
texture_color << return_color.x(), return_color.y(), return_color.z();
Eigen::Vector3f ka = Eigen::Vector3f(0.005, 0.005, 0.005);
Eigen::Vector3f kd = texture_color / 255.f;
Eigen::Vector3f ks = Eigen::Vector3f(0.7937, 0.7937, 0.7937);
auto l1 = light{{20, 20, 20}, {500, 500, 500}};
auto l2 = light{{-20, 20, 0}, {500, 500, 500}};
std::vector<light> lights = {l1, l2};
Eigen::Vector3f amb_light_intensity{10, 10, 10};
Eigen::Vector3f eye_pos{0, 0, 10};
float p = 150;
Eigen::Vector3f color = texture_color;
Eigen::Vector3f point = payload.view_pos;
Eigen::Vector3f normal = payload.normal;
Eigen::Vector3f result_color = {0, 0, 0};
for (auto& light : lights)
{
Eigen::Vector3f light_direction = (light.position - point).normalized();
Eigen::Vector3f view_direction = (eye_pos - point).normalized();
Eigen::Vector3f half_vector = (light_direction + view_direction).normalized();
float reflection_intensity = std::max(0.0f, half_vector.dot(normal));
float light_intensity_attenuation = (light.position - point).dot(light.position - point);
Eigen::Vector3f diffuse_reflection = kd.cwiseProduct(light.intensity / light_intensity_attenuation);
diffuse_reflection *= reflection_intensity;
Eigen::Vector3f high_lights = ks.cwiseProduct(light.intensity / light_intensity_attenuation);
high_lights *= std::pow(reflection_intensity, p);
result_color += (diffuse_reflection + high_lights);
}
Eigen::Vector3f ambient_light_reflection = ka.cwiseProduct(amb_light_intensity);
result_color += ambient_light_reflection;
return result_color * 255.f;
}bump
Eigen::Vector3f bump_fragment_shader(const fragment_shader_payload& payload)
{
Eigen::Vector3f ka = Eigen::Vector3f(0.005, 0.005, 0.005);
Eigen::Vector3f kd = payload.color;
Eigen::Vector3f ks = Eigen::Vector3f(0.7937, 0.7937, 0.7937);
auto l1 = light{{20, 20, 20}, {500, 500, 500}};
auto l2 = light{{-20, 20, 0}, {500, 500, 500}};
std::vector<light> lights = {l1, l2};
Eigen::Vector3f amb_light_intensity{10, 10, 10};
Eigen::Vector3f eye_pos{0, 0, 10};
float p = 150;
Eigen::Vector3f color = payload.color;
Eigen::Vector3f point = payload.view_pos;
Eigen::Vector3f normal = payload.normal;
float kh = 0.2, kn = 0.1;
float x = normal.x();
float y = normal.y();
float z = normal.z();
Eigen::Vector3f t = {-x*y/sqrt(x*x+z*z),sqrt(x*x+z*z),-z*y/sqrt(x*x+z*z)};
Eigen::Vector3f b = normal.cross(t);
Eigen::Matrix3f TBN;
TBN << t.x(), b.x(), normal.x(), t.y(), b.y(), normal.y(), t.z(), b.z(), normal.z();
float u = payload.tex_coords.x();
float v = payload.tex_coords.y();
float w = payload.texture->width;
float h = payload.texture->height;
float dU = kh * kn *(payload.texture->getColor(u + 1.0 / w, v).norm() - payload.texture->getColor(u, v).norm());
float dV = kh * kn *(payload.texture->getColor(u, v + 1.0 / h).norm() - payload.texture->getColor(u, v).norm());
Eigen::Vector3f ln = {-dU, -dV, 1};
normal = (TBN * ln).normalized();
Eigen::Vector3f result_color = {0, 0, 0};
result_color = normal;
return result_color * 255.f;
}displacement
Eigen::Vector3f displacement_fragment_shader(const fragment_shader_payload& payload)
{
Eigen::Vector3f ka = Eigen::Vector3f(0.005, 0.005, 0.005);
Eigen::Vector3f kd = payload.color;
Eigen::Vector3f ks = Eigen::Vector3f(0.7937, 0.7937, 0.7937);
auto l1 = light{{20, 20, 20}, {500, 500, 500}};
auto l2 = light{{-20, 20, 0}, {500, 500, 500}};
std::vector<light> lights = {l1, l2};
Eigen::Vector3f amb_light_intensity{10, 10, 10};
Eigen::Vector3f eye_pos{0, 0, 10};
float p = 150;
Eigen::Vector3f color = payload.color;
Eigen::Vector3f point = payload.view_pos;
Eigen::Vector3f normal = payload.normal;
float kh = 0.2, kn = 0.1;
float x = normal.x();
float y = normal.y();
float z = normal.z();
Eigen::Vector3f t = {-x*y/sqrt(x*x+z*z),sqrt(x*x+z*z),-z*y/sqrt(x*x+z*z)};
Eigen::Vector3f b = normal.cross(t);
Eigen::Matrix3f TBN;
TBN << t.x(), b.x(), normal.x(), t.y(), b.y(), normal.y(), t.z(), b.z(), normal.z();
float u = payload.tex_coords.x();
float v = payload.tex_coords.y();
float w = payload.texture->width;
float h = payload.texture->height;
float dU = kh * kn *(payload.texture->getColor(u + 1.0 / w, v).norm() - payload.texture->getColor(u, v).norm());
float dV = kh * kn *(payload.texture->getColor(u, v + 1.0 / h).norm() - payload.texture->getColor(u, v).norm());
Eigen::Vector3f ln = {-dU, -dV, 1};
normal = (TBN * ln).normalized();
Eigen::Vector3f result_color = {0, 0, 0};
for (auto& light : lights)
{
Eigen::Vector3f light_direction = (light.position - point).normalized();
Eigen::Vector3f view_direction = (eye_pos - point).normalized();
Eigen::Vector3f half_vector = (light_direction + view_direction).normalized();
float reflection_intensity = std::max(0.0f, half_vector.dot(normal));
float light_intensity_attenuation = (light.position - point).dot(light.position - point);
Eigen::Vector3f diffuse_reflection = kd.cwiseProduct(light.intensity / light_intensity_attenuation);
diffuse_reflection *= reflection_intensity;
Eigen::Vector3f high_lights = ks.cwiseProduct(light.intensity / light_intensity_attenuation);
high_lights *= std::pow(reflection_intensity, p);
result_color += (diffuse_reflection + high_lights);
}
Eigen::Vector3f ambient_light_reflection = ka.cwiseProduct(amb_light_intensity);
result_color += ambient_light_reflection;
return result_color * 255.f;
}