Set light intensity to 0 by default (not 1000).

PiperOrigin-RevId: 764257692
Change-Id: If656095e3f8d4b4d9c97fa67bdad508a49095eb3

doc/XMLreference.rst

@@ -2968,7 +2968,7 @@ Attributes may be applied or ignored depending on the lighting model being used.
 
 .. _body-light-intensity:
 
-:at:`intensity`: :at-val:`real, "1000.0"`
+:at:`intensity`: :at-val:`real, "0.0"`
    The intensity of the light source, measured in candela, used for physically-based lighting models.
    This is unused by the default Phong lighting model.
 

src/engine/engine_vis_visualize.c

@@ -2147,7 +2147,7 @@ void mjv_makeLights(const mjModel* m, const mjData* d, mjvScene* scn) {
     thislight->type = mjLIGHT_DIRECTIONAL;
     thislight->castshadow = 0;
     thislight->bulbradius = 0.02;
-    thislight->intensity = 1000;
+    thislight->intensity = 0;
     thislight->range = 10;
 
     // compute head position and gaze direction in model space

src/user/user_init.c

@@ -203,7 +203,7 @@ void mjs_defaultLight(mjsLight* light) {
   // intrinsics
   light->castshadow = 1;
   light->bulbradius = 0.02;
-  light->intensity = 1000.0;
+  light->intensity = 0.0;
   light->range = 10.0;
   light->active = 1;
   light->attenuation[0] = 1;