# `k`: Kinematics library for rust-lang
`k` has below functionalities.
1. Forward kinematics
1. Inverse kinematics
1. URDF Loader
`k` uses [nalgebra](http://nalgebra.org) as math library.
See [Document](http://docs.rs/k) and examples/ for more details.
## IK example with GUI
```bash
cargo run --release --example interactive_ik
```
![ik_sample](img/screenshot.png)
Push below keys to move the end of the manipulator.
- `f`: forward
- `b`: backward
- `p`: up
- `n`: down
- `l`: left
- `r`: right
- `z`: reset the manipulator state.
## Create link tree from urdf and solve IK
```rust
extern crate k;
use k::InverseKinematicsSolver;
use k::KinematicChain;
fn main() {
let robot = k::urdf::create_tree_from_file("urdf/sample.urdf").unwrap();
let mut arms = k::create_kinematic_chains(&robot);
// set joint angles
let angles = vec![0.8, 0.2, 0.0, -1.5, 0.0, -0.3];
arms[0].set_joint_angles(&angles).unwrap();
println!("initial angles={:?}", arms[0].get_joint_angles());
// get the transform of the end of the manipulator (forward kinematics)
let mut target = arms[0].calc_end_transform();
println!("initial target pos = {}", target.translation);
println!("move z: +0.2");
target.translation.vector[2] += 0.2;
let solver = k::JacobianIKSolverBuilder::new().finalize();
// solve and move the manipulator angles
solver
.solve(&mut arms[0], &target)
.unwrap_or_else(|err| {
println!("Err: {}", err);
0.0f32
});
println!("solved angles={:?}", arms[0].get_joint_angles());
println!("solved target pos = {}",
arms[0].calc_end_transform().translation);
}
```