Remove all visual-only assets if discardvisual is selected, not only the geoms.

PiperOrigin-RevId: 598598250
Change-Id: I12e60ce41ad436d037b4877d197decf6bdce0fc8

src/user/user_mesh.cc

@@ -166,6 +166,7 @@ mjCMesh::mjCMesh(mjCModel* _model, mjCDef* _def) {
   valideigenvalue_ = true;
   validinequality_ = true;
   processed_ = false;
+  visual_ = true;
 
   // reset to default if given
   if (_def) {
@@ -708,6 +709,13 @@ void mjCMesh::CopyGraph(int* arr) const {
 
 
 
+void mjCMesh::DelTexcoord() {
+  if (texcoord_) mju_free(texcoord_);
+  ntexcoord_ = 0;
+}
+
+
+
 // set geom size to match mesh
 void mjCMesh::FitGeom(mjCGeom* geom, double* meshpos) {
   // copy mesh pos into meshpos
@@ -2229,6 +2237,15 @@ mjCFlex::mjCFlex(mjCModel* _model) {
 }
 
 
+bool mjCFlex::HasTexcoord() const {
+  return !texcoord.empty();
+}
+
+
+void mjCFlex::DelTexcoord() {
+  texcoord.clear();
+}
+
 
 // compiler
 void mjCFlex::Compile(const mjVFS* vfs) {