add readme.md

Author: Roushelfy

README.md

@@ -0,0 +1,45 @@
+# Muda-based Solid Simulatoion Tutorial
+This is a tutorial for the Solid Simulation using Muda (a CUDA programming paradigm https://github.com/MuGdxy/muda).
+
+The basic architecture of the simulators mimics Minchen Li's Solid-Sim-Tutorial(https://github.com/phys-sim-book/solid-sim-tutorial). 
+
+The tutorial (which is also written by a beginner) may provide some help for the beginners to learn how to write simple CUDA codes for implicit solid simulation.
+## Usage
+1. Clone the repository
+```bash
+git clone https://github.com/Roushelfy/solid-sim-muda
+cd solid-sim-muda
+git submodule update --init --recursive
+```
+
+2. build with cmake
+```bash
+mkdir build
+cd build
+cmake ..
+cmake --build .
+```
+
+## Requirements
+Eigen3==3.4.0
+
+CMake>=3.29
+
+CUDA>=11.0
+
+## Simulators
+
+### 1. Simple Mass-Spring System
+![Simple Mass-Spring System](./img/1.png)
+### 2. Dirichlet Boundary Condition
+![Dirichlet Boundary Condition](./img/2.png)
+### 3. Contact
+![Contact](./img/3.png)
+### 4. Friction
+![Friction](./img/4.png)
+### 5. Moving Dirichlet Boundary
+![Moving Dirichlet Boundary](./img/5.png)
+### 6. Neohookean Model
+![Neohookean Model](./img/6.png)
+### 7. Neohookean Model with Self Collision
+![Neohookean Model with Self Collision](./img/7.png)

img/1.png

@@ -14,7 +14,7 @@ template <typename T, int dim>
 struct MovDirichletSimulator<T, dim>::Impl
 {
     int n_seg;
-    T h, rho, side_len, initial_stretch, m, tol, mu, DBC_stiff;
+    T h, rho, side_len, initial_stretch, m, tol, mu, DBC_stiff = 1000;
     int resolution = 900, scale = 200, offset = resolution / 2, radius = 5;
     std::vector<T> x, x_tilde, v, k, l2, DBC_limit, DBC_v, DBC_target;
     std::vector<int> e, DBC, DBC_satisfied, is_DBC;
@@ -145,7 +145,6 @@ void MovDirichletSimulator<T, dim>::Impl::step_forward()
     update_x_tilde(add_vector<T>(x, v, 1, h));
     frictionenergy.update_mu_lambda(barrierenergy.compute_mu_lambda(mu));
     update_DBC_target();
-    update_DBC_stiff(10);
     DeviceBuffer<T> x_n = x; // Copy current positions to x_n
     update_v(add_vector<T>(x, x_n, 1 / h, -1 / h));
     int iter = 0;