std::shared_ptr<Ray> PerspectiveCamera::GenerateRayForNormalizedCoordinates(glm::vec2 coordinate,
float focus_z,
float aperture_radius) const
{
// Send ray from the camera to the focus plane
// generate rayorigin from random circle around camera location
float theta = RandomFloat(0, 2*3.14159265);
float r = RandomFloat(0, aperture_radius);
const glm::vec2 rand_offsets(r*cos(theta), r*sin(theta));
const glm::vec3 rayOrigin = glm::vec3(GetPosition()) +
glm::vec3(rand_offsets.x * GetRightDirection()) +
glm::vec3(rand_offsets.y * GetUpDirection());
// Figure out where the ray is supposed to point to.
// Imagine that a frustum exists in front of the camera (which we assume exists at a singular point).
// Then, given the aspect ratio and vertical field of view we can determine where in the world the
// image plane will exist and how large it is.
const float planeHeight = std::tan(fov / 2.f) * 2.f;
const float planeWidth = planeHeight * aspectRatio;
// Assume that (0, 0) is the top left of the image which means that when coordinate is (0.5, 0.5) the
// pixel is directly in front of the camera...
const float xOffset = planeWidth * (coordinate.x - 0.5f) * focus_z;
const float yOffset = -1.f * planeHeight * (coordinate.y - 0.5f) * focus_z;
const glm::vec3 targetPosition = glm::vec3(GetPosition()) +
glm::vec3(GetForwardDirection()) * focus_z +
glm::vec3(GetRightDirection()) * xOffset +
glm::vec3(GetUpDirection()) * yOffset;
const glm::vec3 rayDirection = glm::normalize(targetPosition - rayOrigin);
return std::make_shared<Ray>(rayOrigin + rayDirection * zNear, rayDirection, zFar - zNear);
}
void MayaCamera::MousePan(const vec2& delta)
{
m_FocalPoint += -GetRightDirection() * delta.x * m_PanSpeed * m_Distance;
m_FocalPoint += GetUpDirection() * delta.y * m_PanSpeed * m_Distance;
}
