fix tangent space lighting

This commit is contained in:
Lauri Räsänen 2023-01-24 02:21:20 +02:00
parent a17a751fc4
commit de50520b02
4 changed files with 99 additions and 213 deletions

View file

@ -38,151 +38,6 @@ pub async fn load_texture(
return Texture::from_bytes(device, queue, &data, file_name, is_normal_map);
}
pub async fn load_model_obj(
file_name: &str,
device: &wgpu::Device,
queue: &wgpu::Queue,
layout: &wgpu::BindGroupLayout,
) -> anyhow::Result<Model> {
let obj_text = load_string(file_name).await?;
let obj_cursor = Cursor::new(obj_text);
let mut obj_reader = BufReader::new(obj_cursor);
let (models, obj_materials) = tobj::load_obj_buf_async(
&mut obj_reader,
&tobj::LoadOptions {
triangulate: true,
single_index: true,
..Default::default()
},
|p| async move {
let mat_text = load_string(&p).await.unwrap();
tobj::load_mtl_buf(&mut BufReader::new(Cursor::new(mat_text)))
},
)
.await?;
let mut materials = Vec::new();
for m in obj_materials? {
let diffuse_texture_result = load_texture(&m.diffuse_texture, false, device, queue).await;
let normal_texture_result = load_texture(&m.normal_texture, true, device, queue).await;
let diffuse_texture: Texture;
let normal_texture: Texture;
if diffuse_texture_result.is_err() {
diffuse_texture = load_texture("gray.png", false, device, queue).await?;
} else {
diffuse_texture = diffuse_texture_result?;
}
if normal_texture_result.is_err() {
normal_texture = load_texture("gray.png", true, device, queue).await?;
} else {
normal_texture = normal_texture_result?;
}
materials.push(Material::new(
device,
&m.name,
diffuse_texture,
normal_texture,
layout,
));
}
let meshes = models
.into_iter()
.map(|m| {
let mut vertices = (0..m.mesh.positions.len() / 3)
.map(|i| ModelVertex {
position: [
m.mesh.positions[i * 3],
m.mesh.positions[i * 3 + 1],
m.mesh.positions[i * 3 + 2],
],
tex_coords: [m.mesh.texcoords[i * 2], m.mesh.texcoords[i * 2 + 1]],
normal: [
m.mesh.normals[i * 3],
m.mesh.normals[i * 3 + 1],
m.mesh.normals[i * 3 + 2],
],
tangent: [0.0; 4],
bitangent: [0.0; 3],
})
.collect::<Vec<_>>();
let indices = &m.mesh.indices;
let mut triangles_included = vec![0; vertices.len()];
// tangents and bitangents from triangles
for chunk in indices.chunks(3) {
let v0 = vertices[chunk[0] as usize];
let v1 = vertices[chunk[1] as usize];
let v2 = vertices[chunk[2] as usize];
let pos0: cgmath::Vector3<f32> = v0.position.into();
let pos1: cgmath::Vector3<f32> = v1.position.into();
let pos2: cgmath::Vector3<f32> = v2.position.into();
let uv0: cgmath::Vector2<f32> = v0.tex_coords.into();
let uv1: cgmath::Vector2<f32> = v1.tex_coords.into();
let uv2: cgmath::Vector2<f32> = v2.tex_coords.into();
let delta_pos1 = pos1 - pos0;
let delta_pos2 = pos2 - pos0;
let delta_uv1 = uv1 - uv0;
let delta_uv2 = uv2 - uv0;
let r = 1.0 / (delta_uv1.x * delta_uv2.y - delta_uv1.y * delta_uv2.x);
let tangent = (delta_pos1 * delta_uv2.y - delta_pos2 * delta_uv1.y) * r;
let bitangent = (delta_pos2 * delta_uv1.x - delta_pos1 * delta_uv2.x) * -r;
for i in 0..3 {
let sz = chunk[i] as usize;
vertices[sz].tangent =
(cgmath::Vector4::new(tangent.x, tangent.y, tangent.z, 0.0)
+ cgmath::Vector4::from(vertices[sz].tangent))
.into();
vertices[sz].bitangent =
(bitangent + cgmath::Vector3::from(vertices[sz].bitangent)).into();
triangles_included[sz] += 1;
}
}
// Average the tangents/bitangents
for (i, n) in triangles_included.into_iter().enumerate() {
let denom = 1.0 / n as f32;
let mut v = &mut vertices[i];
v.tangent = (cgmath::Vector4::from(v.tangent) * denom).into();
v.bitangent = (cgmath::Vector3::from(v.bitangent) * denom).into();
}
let vertex_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some(&format!("{:?} Vertex Buffer", file_name)),
contents: bytemuck::cast_slice(&vertices),
usage: wgpu::BufferUsages::VERTEX,
});
let index_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some(&format!("{:?} Index Buffer", file_name)),
contents: bytemuck::cast_slice(&m.mesh.indices),
usage: wgpu::BufferUsages::INDEX,
});
return Mesh {
name: file_name.to_string(),
vertex_buffer,
index_buffer,
num_elements: m.mesh.indices.len() as u32,
material: m.mesh.material_id.unwrap_or(0),
};
})
.collect::<Vec<_>>();
return Ok(Model { meshes, materials });
}
pub async fn load_model_gltf(
file_name: &str,
device: &wgpu::Device,
@ -227,58 +82,66 @@ pub async fn load_model_gltf(
panic!();
}
// if let Some(tangent_attribute) = reader.read_tangents() {
// let mut tangent_index = 0;
// tangent_attribute.for_each(|tangent| {
// // dbg!(tangent);
// vertices[tangent_index].tangent = tangent;
// tangent_index += 1;
// });
// }
if let Some(tangent_attribute) = reader.read_tangents() {
println!("gltf: loading tangents from file");
let mut tangent_index = 0;
tangent_attribute.for_each(|tangent| {
// dbg!(tangent);
vertices[tangent_index].tangent = [
tangent[0] * tangent[3],
tangent[1] * tangent[3],
tangent[2] * tangent[3],
];
vertices[tangent_index].bitangent =
cgmath::Vector3::from(vertices[tangent_index].normal)
.cross(cgmath::Vector3::from(vertices[tangent_index].tangent))
.into();
tangent_index += 1;
});
} else {
println!("gltf: no tangents in file, calculating from tris");
// tangents and bitangents from triangles
let mut triangles_included = vec![0; vertices.len()];
for chunk in indices.chunks(3) {
let v0 = vertices[chunk[0] as usize];
let v1 = vertices[chunk[1] as usize];
let v2 = vertices[chunk[2] as usize];
// tangents and bitangents from triangles
let mut triangles_included = vec![0; vertices.len()];
for chunk in indices.chunks(3) {
let v0 = vertices[chunk[0] as usize];
let v1 = vertices[chunk[1] as usize];
let v2 = vertices[chunk[2] as usize];
let pos0: cgmath::Vector3<f32> = v0.position.into();
let pos1: cgmath::Vector3<f32> = v1.position.into();
let pos2: cgmath::Vector3<f32> = v2.position.into();
let pos0: cgmath::Vector3<f32> = v0.position.into();
let pos1: cgmath::Vector3<f32> = v1.position.into();
let pos2: cgmath::Vector3<f32> = v2.position.into();
let uv0: cgmath::Vector2<f32> = v0.tex_coords.into();
let uv1: cgmath::Vector2<f32> = v1.tex_coords.into();
let uv2: cgmath::Vector2<f32> = v2.tex_coords.into();
let uv0: cgmath::Vector2<f32> = v0.tex_coords.into();
let uv1: cgmath::Vector2<f32> = v1.tex_coords.into();
let uv2: cgmath::Vector2<f32> = v2.tex_coords.into();
let delta_pos1 = pos1 - pos0;
let delta_pos2 = pos2 - pos0;
let delta_pos1 = pos1 - pos0;
let delta_pos2 = pos2 - pos0;
let delta_uv1 = uv1 - uv0;
let delta_uv2 = uv2 - uv0;
let delta_uv1 = uv1 - uv0;
let delta_uv2 = uv2 - uv0;
let r = 1.0 / (delta_uv1.x * delta_uv2.y - delta_uv1.y * delta_uv2.x);
let tangent = (delta_pos1 * delta_uv2.y - delta_pos2 * delta_uv1.y) * r;
let bitangent = (delta_pos2 * delta_uv1.x - delta_pos1 * delta_uv2.x) * -r;
let r = 1.0 / (delta_uv1.x * delta_uv2.y - delta_uv1.y * delta_uv2.x);
let tangent = (delta_pos1 * delta_uv2.y - delta_pos2 * delta_uv1.y) * r;
let bitangent = (delta_pos2 * delta_uv1.x - delta_pos1 * delta_uv2.x) * -r;
for i in 0..3 {
let sz = chunk[i] as usize;
vertices[sz].tangent =
(cgmath::Vector4::new(tangent.x, tangent.y, tangent.z, 0.0)
+ cgmath::Vector4::from(vertices[sz].tangent))
.into();
vertices[sz].bitangent =
(bitangent + cgmath::Vector3::from(vertices[sz].bitangent)).into();
triangles_included[sz] += 1;
for i in 0..3 {
let sz = chunk[i] as usize;
vertices[sz].tangent =
(tangent + cgmath::Vector3::from(vertices[sz].tangent)).into();
vertices[sz].bitangent =
(bitangent + cgmath::Vector3::from(vertices[sz].bitangent)).into();
triangles_included[sz] += 1;
}
}
}
// Average the tangents/bitangents
for (i, n) in triangles_included.into_iter().enumerate() {
let denom = 1.0 / n as f32;
let mut v = &mut vertices[i];
v.tangent = (cgmath::Vector4::from(v.tangent) * denom).into();
v.bitangent = (cgmath::Vector3::from(v.bitangent) * denom).into();
// Average the tangents/bitangents
for (i, n) in triangles_included.into_iter().enumerate() {
let denom = 1.0 / n as f32;
let mut v = &mut vertices[i];
v.tangent = (cgmath::Vector3::from(v.tangent) * denom).into();
v.bitangent = (cgmath::Vector3::from(v.bitangent) * denom).into();
}
}
if let Some(tex_coord_attribute) = reader.read_tex_coords(0).map(|v| v.into_f32()) {