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update projection matrices

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This commit is contained in:
Hartmut Seichter 2022-12-20 17:13:17 +01:00
parent 3ebc7b5c51
commit 6c8c9d70cb
3 changed files with 27 additions and 22 deletions
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35
src/projection.rs
View file

@ -29,8 +29,8 @@ pub fn make_projection_rh_from_frustum(
Mat4::from_cols(
Vec4::new(2.0 * near / (right - left), 0.0, 0.0, 0.0),
Vec4::new(0.0, 2.0 * near / (top - bottom), 0.0, 0.0),
Vec4::new(a, b, c, -1.0),
Vec4::new(0.0, 0.0, d, 0.0),
Vec4::new(0.0, 0.0, c, -1.0),
Vec4::new(a, b, d, 0.0),
)
}
@ -45,21 +45,25 @@ pub fn make_projection_rh_from_frustum_reversed(
) -> Mat4 {
assert!(z_near > 0.0 && z_far > 0.0);
info!("near {:?}",z_near);
info!("near {:?}", z_near);
//
// reversed z 0..1 projection based on https://thxforthefish.com/posts/reverse_z/
// reversed z 0..1 projection based on https://thxforthefish.com/posts/reverse_z/ and
// https://vincent-p.github.io/posts/vulkan_perspective_matrix/
//
let a = (right + left) / (right - left);
let b = (top + bottom) / (top - bottom);
let c = z_near / (z_far - z_near);
let d = z_far * z_near / (z_far - z_near);
let sx = 2.0 * z_near / (right - left);
let sy = 2.0 * z_near / (top - bottom);
let a = (right + left) / (right - left); // position in frame horizontal
let b = (top + bottom) / (top - bottom); // position in frame vertical
// for reverse z 0..1
let c = z_near / (z_far - z_near); // lower bound
let d = z_far * z_near / (z_far - z_near); // upper bound
let sx = 2.0 * z_near / (right - left); // scale x
let sy = 2.0 * z_near / (top - bottom); // scale y
// reverse z 0..1
// --------------
// sx 0 a 0
// 0 sy b 0
// 0 0 c d
@ -68,8 +72,8 @@ pub fn make_projection_rh_from_frustum_reversed(
Mat4::from_cols(
Vec4::new(sx, 0.0, 0.0, 0.0),
Vec4::new(0.0, sy, 0.0, 0.0),
Vec4::new(0.0, 0.0, c, -1.0),
Vec4::new(a, b, d, 0.0),
Vec4::new(a, b, c, -1.0),
Vec4::new(0.0, 0.0, d, 0.0),
)
}
@ -130,7 +134,7 @@ pub fn create_offaxis_matrices(
let bottom = vec_up_normalized.dot(frustum_left) * z_near / dist; // bottom screen edge
let top = vec_up_normalized.dot(frustum_up) * z_near / dist; // distance eye from screen
info!("l r b t {} {} {} {}",left,right,bottom,top);
info!("l r b t {} {} {} {}", left, right, bottom, top);
// create a view frustum
let projection_matrix =
@ -166,7 +170,8 @@ pub fn create_offaxis_matrices(
let view_matrix_eye = Mat4::from_cols(Vec4::X, Vec4::Y, Vec4::Z, (-pos_eye).extend(1.0));
// create resulting view matrix (this should be much simpler using glam API)
let view_matrix = view_matrix_rotation * view_matrix_eye;
let view_matrix = view_matrix_eye * view_matrix_rotation;
//view_matrix_rotation * view_matrix_eye;
// info!("{:?}",view_matrix_eye);

6
src/scene.rs
View file

@ -7,7 +7,7 @@ pub fn build_scene(
) {
// plane
commands.spawn(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Plane { size: 4.0 })),
mesh: meshes.add(Mesh::from(shape::Plane { size: 2.5 })),
material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
transform: Transform::from_xyz(0.0, -0.5, 0.0),
..default()
@ -16,7 +16,7 @@ pub fn build_scene(
commands.spawn(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.5 })),
material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
transform: Transform::from_xyz(0.0, 0.5, -3.0),
transform: Transform::from_xyz(0.0, 0.5, -1.5),
..default()
});
// light
@ -26,7 +26,7 @@ pub fn build_scene(
shadows_enabled: true,
..default()
},
transform: Transform::from_xyz(4.0, 1.0, -4.0),
transform: Transform::from_xyz(4.0, 4.0, -1.5),
..default()
});
}

2
src/viewer.rs
View file

@ -87,7 +87,7 @@ pub fn simulate_viewer_with_keyboard(
for mut viewer in query.iter_mut() {
if input.pressed(KeyCode::W) {
viewer.position += Vec3::Z * time.delta_seconds();
} else if (input.pressed(KeyCode::S)) {
} else if input.pressed(KeyCode::S) {
viewer.position -= Vec3::Z * time.delta_seconds();
} else if input.pressed(KeyCode::A) {
viewer.position -= Vec3::X * time.delta_seconds();