BulletSim: fix race condition when creating very large mega-regions.

The symptom was exceptions while creating physical terrain.
Reduce default terrain mesh magnification to 2 from 3 because the
higher resolution uses a lot of memory and doesn't solve the terrain
smoothness for vehicles.
Added comments here and there and improved some debugging log messages.

1 files changed, 3 insertions, 0 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSMaterials.cs b/OpenSim/Region/Physics/BulletSPlugin/BSMaterials.cs
index 92d62ff..ee77d6e 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSMaterials.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSMaterials.cs
@@ -180,11 +180,14 @@ public static class BSMaterials
     // Use reflection to set the value in the attribute structure.
     private static void SetAttributeValue(int matType, string attribName, float val)
     {
+        // Get the current attribute values for this material
         MaterialAttributes thisAttrib = Attributes[matType];
+        // Find the field for the passed attribute name (eg, find field named 'friction')
         FieldInfo fieldInfo = thisAttrib.GetType().GetField(attribName.ToLower());
         if (fieldInfo != null)
         {
             fieldInfo.SetValue(thisAttrib, val);
+            // Copy new attributes back to array -- since MaterialAttributes is 'struct', passed by value, not reference.
             Attributes[matType] = thisAttrib;
         }
     }