Update MuJoCo changelog with a video of the 100_humanoids model.

Improve the model's rendering FPS by reducing the number of shadow-casting lights from 7 to 2.

https://youtu.be/e8lUuykQPGs

PiperOrigin-RevId: 686118052
Change-Id: If376564fdc23ad8d754dac1e5825079c0b806063

doc/changelog.rst

@@ -8,6 +8,10 @@ Upcoming version (not yet released)
 General
 ^^^^^^^
 
+.. youtube:: e8lUuykQPGs
+   :align: right
+   :width: 240px
+
 - The Newton solver no longer requires ``nv*nv`` memory allocation, allowing for much larger models. See e.g.,
   `100_humanoids.xml  <https://github.com/google-deepmind/mujoco/blob/main/model/humanoid/100_humanoids.xml>`__.
   Two quadratic-memory allocations still remain to be fully sparsified: ``mjData.actuator_moment`` and the matrices used

model/humanoid/100_humanoids.xml

@@ -28,13 +28,13 @@
   <visual>
     <map force="0.1" zfar="30"/>
     <rgba haze="0.15 0.25 0.35 1"/>
-    <quality shadowsize="4096" numslices="16" numstacks="8"/>
+    <quality numslices="16" numstacks="8"/>
     <global offwidth="800" offheight="800"/>
   </visual>
 
   <worldbody>
     <geom name="floor" size="10 10 .05" type="plane" material="floor" condim="3"/>
-    <light directional="true" diffuse=".4 .4 .4" specular="0.1 0.1 0.1" pos="0 0 5" dir="0 0 -1" castshadow="false"/>
+    <light directional="true" diffuse=".9 .9 .9" specular="0.1 0.1 0.1" pos="0 0 5" dir="0 0 -1" castshadow="true"/>
     <light name="spotlight" mode="targetbodycom" target="world" diffuse="1 1 1" specular="0.3 0.3 0.3" pos="-6 -6 4" cutoff="60"/>
     <replicate count="10" euler="0 0 36" sep="-">
       <frame pos="1 0 0">
@@ -43,8 +43,5 @@
         </replicate>
       </frame>
     </replicate>
-    <replicate count="5" euler="0 0 72" sep="-">
-      <light pos="0 -4 4"/>
-    </replicate>
   </worldbody>
 </mujoco>