Add output attribute to camera elements.

This attribute allows specifying the intended output types (e.g., RGB, depth, normal) for each camera in the XML. The output types are stored as bit flags in `mjModel`.

PiperOrigin-RevId: 853316261
Change-Id: I1ad2e94102593cf402756f8f4c80509371ca86d2

include/mujoco/mjmodel.h

@@ -416,6 +416,17 @@ typedef enum mjtRayDataField_ {   // data fields returned by rangefinder sensors
 } mjtRayDataField;
 
 
+typedef enum mjtCamOutBit_ {      // camera output type bitflags
+  mjCAMOUT_RGB        = 1<<0,     // RGB image
+  mjCAMOUT_DEPTH      = 1<<1,     // depth image (distance from camera plane)
+  mjCAMOUT_DIST       = 1<<2,     // distance image (distance from camera origin)
+  mjCAMOUT_NORMAL     = 1<<3,     // normal image
+  mjCAMOUT_SEG        = 1<<4,     // segmentation image
+
+  mjNCAMOUT           = 5         // number of camera output types
+} mjtCamOutBit;
+
+
 typedef enum mjtSameFrame_ {      // frame alignment of bodies with their children
   mjSAMEFRAME_NONE    = 0,        // no alignment
   mjSAMEFRAME_BODY,               // frame is same as body frame
@@ -903,6 +914,7 @@ struct mjModel_ {
   mjtNum*   cam_fovy;             // y field-of-view (ortho ? len : deg)      (ncam x 1)
   mjtNum*   cam_ipd;              // inter-pupilary distance                  (ncam x 1)
   int*      cam_resolution;       // resolution: pixels [width, height]       (ncam x 2)
+  int*      cam_output;           // output types (mjtCamOut bit flags)       (ncam x 1)
   float*    cam_sensorsize;       // sensor size: length [width, height]      (ncam x 2)
   float*    cam_intrinsic;        // [focal length; principal point]          (ncam x 4)
   mjtNum*   cam_user;             // user data                                (ncam x nuser_cam)

include/mujoco/mjspec.h

@@ -375,6 +375,7 @@ typedef struct mjsCamera_ {        // camera specification
   // intrinsics
   mjtProjection proj;              // camera projection type
   int resolution[2];               // resolution (pixel)
+  int output;                      // bit flags for output type
   double fovy;                     // y-field of view
   double ipd;                      // inter-pupillary distance
   float intrinsic[4];              // camera intrinsics (length)

include/mujoco/mjxmacro.h

@@ -306,6 +306,7 @@
     X   ( mjtNum,  cam_fovy,              ncam,          1                    ) \
     X   ( mjtNum,  cam_ipd,               ncam,          1                    ) \
     X   ( int,     cam_resolution,        ncam,          2                    ) \
+    X   ( int,     cam_output,            ncam,          1                    ) \
     X   ( float,   cam_sensorsize,        ncam,          2                    ) \
     X   ( float,   cam_intrinsic,         ncam,          4                    ) \
     X   ( mjtNum,  cam_user,              ncam,          MJ_M(nuser_cam)      )