Add elasticity parameters to the schema.

PiperOrigin-RevId: 675115200
Change-Id: Ic6608ce61cbb857dca71b3d9cbdac057e8f1ac7a

src/user/user_init.c

@@ -236,6 +236,7 @@ void mjs_defaultFlex(mjsFlex* flex) {
   flex->activelayers = 1;
   flex->rgba[0] = flex->rgba[1] = flex->rgba[2] = 0.5f;
   flex->rgba[3] = 1.0f;
+  flex->thickness = -1;
 }
 
 

src/user/user_mesh.cc

@@ -2675,6 +2675,18 @@ void mjCFlex::Compile(const mjVFS* vfs) {
     if (model->Bodies()[vbodyid]->plugin.instance) {
       mjCPlugin* plugin_instance =
           static_cast<mjCPlugin*>(model->Bodies()[vbodyid]->plugin.instance);
+      if (young > 0) {
+        plugin_instance->config_attribs["young"] = std::to_string(young);
+      }
+      if (poisson > 0) {
+        plugin_instance->config_attribs["poisson"] = std::to_string(poisson);
+      }
+      if (thickness > 0) {
+        plugin_instance->config_attribs["thickness"] = std::to_string(thickness);
+      }
+      if (damping > 0) {
+        plugin_instance->config_attribs["damping"] = std::to_string(damping);
+      }
       plugin_instance->config_attribs["face"] = userface;
       plugin_instance->config_attribs["edge"] = useredge;
     }