From 8510f57ad48db5f97dacc2a9be63c64e62477d14 Mon Sep 17 00:00:00 2001 From: Robert Adams Date: Sun, 17 Mar 2013 18:44:09 -0700 Subject: BulletSim: add terrain contact processing threshold parameter. Initialize contact processing threshold for static object as well as mesh terrain. --- OpenSim/Region/Physics/BulletSPlugin/BSParam.cs | 19 +++++++++++++++++++ OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs | 2 +- .../Region/Physics/BulletSPlugin/BSTerrainManager.cs | 1 + OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs | 2 ++ 4 files changed, 23 insertions(+), 1 deletion(-) (limited to 'OpenSim') diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs index 77bdacb..cb0d929 100755 --- a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs +++ b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs @@ -39,6 +39,20 @@ public static class BSParam { private static string LogHeader = "[BULLETSIM PARAMETERS]"; + // Tuning notes: + // From: http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=6575 + // Contact points can be added even if the distance is positive. The constraint solver can deal with + // contacts with positive distances as well as negative (penetration). Contact points are discarded + // if the distance exceeds a certain threshold. + // Bullet has a contact processing threshold and a contact breaking threshold. + // If the distance is larger than the contact breaking threshold, it will be removed after one frame. + // If the distance is larger than the contact processing threshold, the constraint solver will ignore it. + + // This is separate/independent from the collision margin. The collision margin increases the object a bit + // to improve collision detection performance and accuracy. + // =================== + // From: + // Level of Detail values kept as float because that's what the Meshmerizer wants public static float MeshLOD { get; private set; } public static float MeshCircularLOD { get; private set; } @@ -77,6 +91,7 @@ public static class BSParam public static float TerrainFriction { get; private set; } public static float TerrainHitFraction { get; private set; } public static float TerrainRestitution { get; private set; } + public static float TerrainContactProcessingThreshold { get; private set; } public static float TerrainCollisionMargin { get; private set; } public static float DefaultFriction { get; private set; } @@ -458,6 +473,10 @@ public static class BSParam 0f, (s) => { return TerrainRestitution; }, (s,v) => { TerrainRestitution = v; /* TODO: set on real terrain */ } ), + new ParameterDefn("TerrainContactProcessingThreshold", "Distance from terrain to stop processing collisions" , + 0.0f, + (s) => { return TerrainContactProcessingThreshold; }, + (s,v) => { TerrainContactProcessingThreshold = v; /* TODO: set on real terrain */ } ), new ParameterDefn("TerrainCollisionMargin", "Margin where collision checking starts" , 0.08f, (s) => { return TerrainCollisionMargin; }, diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs index a465613..2cbbe9a 100644 --- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs +++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs @@ -947,9 +947,9 @@ public class BSPrim : BSPhysObject ZeroMotion(true); // Set various physical properties so other object interact properly - MaterialAttributes matAttrib = BSMaterials.GetAttributes(Material, false); PhysicsScene.PE.SetFriction(PhysBody, Friction); PhysicsScene.PE.SetRestitution(PhysBody, Restitution); + PhysicsScene.PE.SetContactProcessingThreshold(PhysBody, BSParam.ContactProcessingThreshold); // Mass is zero which disables a bunch of physics stuff in Bullet UpdatePhysicalMassProperties(0f, false); diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs index e8040d8..a60946d 100755 --- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs +++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs @@ -263,6 +263,7 @@ public sealed class BSTerrainManager : IDisposable if (MegaRegionParentPhysicsScene == null) { + // This terrain is not part of the mega-region scheme. Create vanilla terrain. BSTerrainPhys newTerrainPhys = BuildPhysicalTerrain(terrainRegionBase, id, heightMap, minCoords, maxCoords); m_terrains.Add(terrainRegionBase, newTerrainPhys); diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs index 57a5ff2..c9a75ae 100755 --- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs +++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs @@ -112,11 +112,13 @@ public sealed class BSTerrainMesh : BSTerrainPhys // Something is very messed up and a crash is in our future. return; } + physicsScene.PE.SetShapeCollisionMargin(m_terrainShape, BSParam.TerrainCollisionMargin); // Set current terrain attributes PhysicsScene.PE.SetFriction(m_terrainBody, BSParam.TerrainFriction); PhysicsScene.PE.SetHitFraction(m_terrainBody, BSParam.TerrainHitFraction); PhysicsScene.PE.SetRestitution(m_terrainBody, BSParam.TerrainRestitution); + PhysicsScene.PE.SetContactProcessingThreshold(m_terrainBody, BSParam.TerrainContactProcessingThreshold); PhysicsScene.PE.SetCollisionFlags(m_terrainBody, CollisionFlags.CF_STATIC_OBJECT); // Static objects are not very massive. -- cgit v1.1