Add flex_elemlayer to mjvSceneState. Fixes #1193 and #1219.

PiperOrigin-RevId: 585581657
Change-Id: Iec4da74437544184c19765a2feee1cca4c368d34

doc/changelog.rst

@@ -28,6 +28,7 @@ Bug fixes
 ^^^^^^^^^
 - Fix bug in Cartesian actuation with movable refsite, as when using body-centric Cartesian actuators on a quadruped.
   Before this fix such actuators could lead to non-conservation of momentum.
+- Fix bug that prevented using flex with the :ref:`passive viewer<PyViewerPassive>`.
 
 Version 3.0.1 (November 15, 2023)
 ---------------------------------

doc/includes/references.h

@@ -2235,6 +2235,7 @@ struct mjvSceneState_ {
     int* flex_vertadr;
     int* flex_vertnum;
     int* flex_elem;
+    int* flex_elemlayer;
     int* flex_elemadr;
     int* flex_elemnum;
     int* flex_elemdataadr;

include/mujoco/mjvisualize.h

@@ -507,6 +507,7 @@ struct mjvSceneState_ {
     int* flex_vertadr;
     int* flex_vertnum;
     int* flex_elem;
+    int* flex_elemlayer;
     int* flex_elemadr;
     int* flex_elemnum;
     int* flex_elemdataadr;

include/mujoco/mjxmacro.h

@@ -334,7 +334,7 @@
     X   ( int,     flex_vertbodyid,       nflexvert,     1                    ) \
     X   ( int,     flex_edge,             nflexedge,     2                    ) \
     XMJV( int,     flex_elem,             nflexelemdata, 1                    ) \
-    X   ( int,     flex_elemlayer,        nflexelem,     1                    ) \
+    XMJV( int,     flex_elemlayer,        nflexelem,     1                    ) \
     XMJV( int,     flex_shell,            nflexshelldata,1                    ) \
     X   ( int,     flex_evpair,           nflexevpair,   2                    ) \
     X   ( mjtNum,  flex_vert,             nflexvert,     3                    ) \

introspect/structs.py

@@ -6741,6 +6741,13 @@ STRUCTS: Mapping[str, StructDecl] = dict([
                              ),
                              doc='',
                          ),
+                         StructFieldDecl(
+                             name='flex_elemlayer',
+                             type=PointerType(
+                                 inner_type=ValueType(name='int'),
+                             ),
+                             doc='',
+                         ),
                          StructFieldDecl(
                              name='flex_elemadr',
                              type=PointerType(

unity/Runtime/Bindings/MjBindings.cs

@@ -6152,6 +6152,7 @@ public unsafe struct model {
   public int* flex_vertadr;
   public int* flex_vertnum;
   public int* flex_elem;
+  public int* flex_elemlayer;
   public int* flex_elemadr;
   public int* flex_elemnum;
   public int* flex_elemdataadr;