Update DynamicStrands.hpp

edisonlee0212 · Oct 14, 2024 · 9266add · 9266add
1 parent 02e4978
commit 9266add
Showing 1 changed file with 14 additions and 8 deletions.
diff --git a/EvoEngine_Plugins/EcoSysLab/include/StrandModel/DynamicStrands.hpp b/EvoEngine_Plugins/EcoSysLab/include/StrandModel/DynamicStrands.hpp
@@ -14,9 +14,10 @@ class DynamicStrands {
   DynamicStrands();
 #pragma region Initialization
   struct InitializeParameters {
+    bool static_root = true;
     float wood_density = 1.f;
-    float youngs_modulus;
-    float torsion_modulus;
+    float youngs_modulus = 1.f;
+    float torsion_modulus = 1.f;
     GlobalTransform root_transform{};
   };
   template <typename StrandGroupData, typename StrandData, typename StrandSegmentData>
@@ -163,12 +164,17 @@ void DynamicStrands::InitializeStrandsGroup(const InitializeParameters& initiali
 
     segment.x0 = segment.x;
 
-    segment.mass = segment.radius * segment.radius * glm::pi<float>() * initialize_parameters.wood_density;
-    segment.inv_mass = 1.f / segment.mass;
-    const float inertia = .2f * segment.mass * segment.radius * segment.radius;
-    segment.inertia_tensor = glm::vec3(inertia, inertia, 2.f * inertia);
-    segment.inv_inertia_tensor = 1.f / segment.inertia_tensor;
-
+    if (initialize_parameters.static_root) {
+      segment.mass = segment.inv_mass = 0.0f;
+      segment.inertia_tensor = segment.inv_inertia_tensor = glm::vec3(0.0f);
+    }else {
+      segment.mass = segment.radius * segment.radius * glm::pi<float>() * initialize_parameters.wood_density;
+      segment.inv_mass = 1.f / segment.mass;
+      const float inertia = .2f * segment.mass * segment.radius * segment.radius;
+      segment.inertia_tensor = glm::vec3(inertia, inertia, 2.f * inertia);
+      segment.inv_inertia_tensor = 1.f / segment.inertia_tensor;
+    }
+
     segment.length = strand_group.GetStrandSegmentLength(static_cast<int>(i));
   });
   Upload();