[Feature] Blood, vessels and heart simulations

genesis/engine/entities/multiphase_sph_entity.py

@@ -0,0 +1,68 @@
+import taichi as ti
+import genesis as gs
+from .sph_entity import SPHEntity
+
+
+@ti.data_oriented
+class MultiphaseSPHEntity(SPHEntity):
+    """
+    SPH-based particle entity with multiphase support.
+    """
+
+    def __init__(
+        self,
+        scene,
+        solver,
+        material,
+        morph,
+        surface,
+        particle_size,
+        idx,
+        particle_start,
+        phase,
+    ):
+        """
+        Initialize a MultiphaseSPHEntity.
+        """
+        self.phase = phase  # Store phase information
+        super().__init__(
+            scene, solver, material, morph, surface, particle_size, idx, particle_start
+        )
+
+    def _add_to_solver_(self):
+        """
+        Adds particles to the solver with phase information.
+        """
+        self._solver._kernel_add_particles(
+            self._sim.cur_substep_local,
+            self.active,
+            self._particle_start,
+            self._n_particles,
+            self._material["rho"],
+            self._material["stiffness"],
+            self._material["exponent"],
+            self._material["mu"],
+            self._material["gamma"],
+            self._material["tau_y"],
+            self._material["K"],
+            self._material["n"],
+            self.phase,  # Pass phase information
+            self._particles,
+        )
+
+    @gs.assert_built
+    def set_phase(self, f, phase):
+        """
+        Sets the phase of the entity's particles.
+
+        Parameters:
+            f: Frame index or identifier.
+            phase: Integer identifier for the new phase.
+        """
+        self.phase = phase
+        self.solver._kernel_set_particle_phase(
+            f,
+            self._particle_start,
+            self._n_particles,
+            phase,
+        )