Disable hfields for collision sensors.

PiperOrigin-RevId: 685730321
Change-Id: Ib1d4a90b7b31ca388e018076a274e25c40409080

doc/changelog.rst

@@ -31,6 +31,8 @@ Bug fixes
 ^^^^^^^^^
 - Fixed a bug where ``actuator_force`` was not set in MJX (:github:issue:`2068`).
 - Fixed bug where MJX data tendon fields were incorrect after calling ``mjx.put_data``.
+- The compiler now returns an error if height fields are used with :ref:`collision sensors<collision-sensors>` as they
+  are not yet supported.
 
 
 Version 3.2.3 (Sep 16, 2024)

src/user/user_objects.cc

@@ -6399,6 +6399,12 @@ void mjCSensor::Compile(void) {
       throw mjCError(this, "1st body/geom must be different from 2nd body/geom");
     }
 
+    // height fields are not necessarily convex and are not yet supported
+    if (static_cast<mjCGeom*>(obj)->Type() == mjGEOM_HFIELD ||
+        static_cast<mjCGeom*>(ref)->Type() == mjGEOM_HFIELD) {
+      throw mjCError(this, "height fields are not supported in geom distance sensors");
+    }
+
     // set
     needstage = mjSTAGE_POS;
     if (type==mjSENS_GEOMDIST) {

src/user/user_objects.h

@@ -530,6 +530,7 @@ class mjCGeom : public mjCGeom_, private mjsGeom {
   void SetInertia(void);              // compute and set geom inertia
   bool IsVisual(void) const { return visual_; }
   void SetNotVisual(void) { visual_ = false; }
+  mjtGeom Type() const { return type; }
 
   // Compute all coefs modeling the interaction with the surrounding fluid.
   void SetFluidCoefs(void);

test/engine/testdata/sensor/fromto_convex.xml

@@ -61,23 +61,15 @@
     <fromto geom1="ellipsoid" geom2="box" cutoff="1"/>
     <fromto geom1="ellipsoid" geom2="cylinder" cutoff="1"/>
     <fromto geom1="ellipsoid" geom2="mesh2" cutoff="1"/>
-    <fromto geom1="ellipsoid" geom2="hfield" cutoff="1"/>
     <fromto geom1="mesh1" geom2="sphere" cutoff="1"/>
     <fromto geom1="mesh1" geom2="box" cutoff="1"/>
     <fromto geom1="mesh1" geom2="mesh2" cutoff="1"/>
-    <fromto geom1="hfield" geom2="sphere" cutoff="1"/>
-    <fromto geom1="hfield" geom2="box" cutoff="1"/>
-    <fromto geom1="hfield" geom2="mesh1" cutoff="1"/>
 
     <fromto geom1="ellipsoid" geom2="box" cutoff="0.2"/>
     <fromto geom1="ellipsoid" geom2="cylinder" cutoff="0.2"/>
     <fromto geom1="ellipsoid" geom2="mesh2" cutoff="0.2"/>
-    <fromto geom1="ellipsoid" geom2="hfield" cutoff="0.2"/>
     <fromto geom1="mesh1" geom2="sphere" cutoff="0.2"/>
     <fromto geom1="mesh1" geom2="box" cutoff="0.2"/>
     <fromto geom1="mesh1" geom2="mesh2" cutoff="0.2"/>
-    <fromto geom1="hfield" geom2="sphere" cutoff="0.2"/>
-    <fromto geom1="hfield" geom2="box" cutoff="0.2"/>
-    <fromto geom1="hfield" geom2="mesh1" cutoff="0.2"/>
   </sensor>
 </mujoco>