/// <summary> /// Recalculates the axis aligned bounding box and the inertia /// values in world space. /// </summary> public virtual void Update() { if (isParticle) { this.inertia = TSMatrix.Zero; this.invInertia = this.invInertiaWorld = TSMatrix.Zero; this.invOrientation = this.orientation = TSMatrix.Identity; this.boundingBox = shape.boundingBox; TSVector.Add(ref boundingBox.min, ref this.position, out boundingBox.min); TSVector.Add(ref boundingBox.max, ref this.position, out boundingBox.max); angularVelocity.MakeZero(); } else { // Given: Orientation, Inertia TSMatrix.Transpose(ref orientation, out invOrientation); this.Shape.GetBoundingBox(ref orientation, out boundingBox); TSVector.Add(ref boundingBox.min, ref this.position, out boundingBox.min); TSVector.Add(ref boundingBox.max, ref this.position, out boundingBox.max); if (!isStatic) { TSMatrix.Multiply(ref invOrientation, ref invInertia, out invInertiaWorld); TSMatrix.Multiply(ref invInertiaWorld, ref orientation, out invInertiaWorld); } } }
/// <summary> /// PrepareForIteration has to be called before <see cref="Iterate"/>. /// </summary> /// <param name="timestep">The timestep of the simulation.</param> public void PrepareForIteration(FP timestep) { FP dvx, dvy, dvz; dvx = (body2.angularVelocity.y * relativePos2.z) - (body2.angularVelocity.z * relativePos2.y) + body2.linearVelocity.x; dvy = (body2.angularVelocity.z * relativePos2.x) - (body2.angularVelocity.x * relativePos2.z) + body2.linearVelocity.y; dvz = (body2.angularVelocity.x * relativePos2.y) - (body2.angularVelocity.y * relativePos2.x) + body2.linearVelocity.z; dvx = dvx - (body1.angularVelocity.y * relativePos1.z) + (body1.angularVelocity.z * relativePos1.y) - body1.linearVelocity.x; dvy = dvy - (body1.angularVelocity.z * relativePos1.x) + (body1.angularVelocity.x * relativePos1.z) - body1.linearVelocity.y; dvz = dvz - (body1.angularVelocity.x * relativePos1.y) + (body1.angularVelocity.y * relativePos1.x) - body1.linearVelocity.z; FP kNormal = FP.Zero; TSVector rantra = TSVector.zero; if (!treatBody1AsStatic) { kNormal += body1.inverseMass; if (!body1IsMassPoint) { // JVector.Cross(ref relativePos1, ref normal, out rantra); rantra.x = (relativePos1.y * normal.z) - (relativePos1.z * normal.y); rantra.y = (relativePos1.z * normal.x) - (relativePos1.x * normal.z); rantra.z = (relativePos1.x * normal.y) - (relativePos1.y * normal.x); // JVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra); FP num0 = ((rantra.x * body1.invInertiaWorld.M11) + (rantra.y * body1.invInertiaWorld.M21)) + (rantra.z * body1.invInertiaWorld.M31); FP num1 = ((rantra.x * body1.invInertiaWorld.M12) + (rantra.y * body1.invInertiaWorld.M22)) + (rantra.z * body1.invInertiaWorld.M32); FP num2 = ((rantra.x * body1.invInertiaWorld.M13) + (rantra.y * body1.invInertiaWorld.M23)) + (rantra.z * body1.invInertiaWorld.M33); rantra.x = num0; rantra.y = num1; rantra.z = num2; //JVector.Cross(ref rantra, ref relativePos1, out rantra); num0 = (rantra.y * relativePos1.z) - (rantra.z * relativePos1.y); num1 = (rantra.z * relativePos1.x) - (rantra.x * relativePos1.z); num2 = (rantra.x * relativePos1.y) - (rantra.y * relativePos1.x); rantra.x = num0; rantra.y = num1; rantra.z = num2; } } TSVector rbntrb = TSVector.zero; if (!treatBody2AsStatic) { kNormal += body2.inverseMass; if (!body2IsMassPoint) { // JVector.Cross(ref relativePos1, ref normal, out rantra); rbntrb.x = (relativePos2.y * normal.z) - (relativePos2.z * normal.y); rbntrb.y = (relativePos2.z * normal.x) - (relativePos2.x * normal.z); rbntrb.z = (relativePos2.x * normal.y) - (relativePos2.y * normal.x); // JVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra); FP num0 = ((rbntrb.x * body2.invInertiaWorld.M11) + (rbntrb.y * body2.invInertiaWorld.M21)) + (rbntrb.z * body2.invInertiaWorld.M31); FP num1 = ((rbntrb.x * body2.invInertiaWorld.M12) + (rbntrb.y * body2.invInertiaWorld.M22)) + (rbntrb.z * body2.invInertiaWorld.M32); FP num2 = ((rbntrb.x * body2.invInertiaWorld.M13) + (rbntrb.y * body2.invInertiaWorld.M23)) + (rbntrb.z * body2.invInertiaWorld.M33); rbntrb.x = num0; rbntrb.y = num1; rbntrb.z = num2; //JVector.Cross(ref rantra, ref relativePos1, out rantra); num0 = (rbntrb.y * relativePos2.z) - (rbntrb.z * relativePos2.y); num1 = (rbntrb.z * relativePos2.x) - (rbntrb.x * relativePos2.z); num2 = (rbntrb.x * relativePos2.y) - (rbntrb.y * relativePos2.x); rbntrb.x = num0; rbntrb.y = num1; rbntrb.z = num2; } } if (!treatBody1AsStatic) { kNormal += rantra.x * normal.x + rantra.y * normal.y + rantra.z * normal.z; } if (!treatBody2AsStatic) { kNormal += rbntrb.x * normal.x + rbntrb.y * normal.y + rbntrb.z * normal.z; } massNormal = FP.One / kNormal; FP num = dvx * normal.x + dvy * normal.y + dvz * normal.z; tangent.x = dvx - normal.x * num; tangent.y = dvy - normal.y * num; tangent.z = dvz - normal.z * num; num = tangent.x * tangent.x + tangent.y * tangent.y + tangent.z * tangent.z; if (num != FP.Zero) { num = FP.Sqrt(num); tangent.x /= num; tangent.y /= num; tangent.z /= num; } FP kTangent = FP.Zero; if (treatBody1AsStatic) { rantra.MakeZero(); } else { kTangent += body1.inverseMass; if (!body1IsMassPoint) { // JVector.Cross(ref relativePos1, ref normal, out rantra); rantra.x = (relativePos1.y * tangent.z) - (relativePos1.z * tangent.y); rantra.y = (relativePos1.z * tangent.x) - (relativePos1.x * tangent.z); rantra.z = (relativePos1.x * tangent.y) - (relativePos1.y * tangent.x); // JVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra); FP num0 = ((rantra.x * body1.invInertiaWorld.M11) + (rantra.y * body1.invInertiaWorld.M21)) + (rantra.z * body1.invInertiaWorld.M31); FP num1 = ((rantra.x * body1.invInertiaWorld.M12) + (rantra.y * body1.invInertiaWorld.M22)) + (rantra.z * body1.invInertiaWorld.M32); FP num2 = ((rantra.x * body1.invInertiaWorld.M13) + (rantra.y * body1.invInertiaWorld.M23)) + (rantra.z * body1.invInertiaWorld.M33); rantra.x = num0; rantra.y = num1; rantra.z = num2; //JVector.Cross(ref rantra, ref relativePos1, out rantra); num0 = (rantra.y * relativePos1.z) - (rantra.z * relativePos1.y); num1 = (rantra.z * relativePos1.x) - (rantra.x * relativePos1.z); num2 = (rantra.x * relativePos1.y) - (rantra.y * relativePos1.x); rantra.x = num0; rantra.y = num1; rantra.z = num2; } } if (treatBody2AsStatic) { rbntrb.MakeZero(); } else { kTangent += body2.inverseMass; if (!body2IsMassPoint) { // JVector.Cross(ref relativePos1, ref normal, out rantra); rbntrb.x = (relativePos2.y * tangent.z) - (relativePos2.z * tangent.y); rbntrb.y = (relativePos2.z * tangent.x) - (relativePos2.x * tangent.z); rbntrb.z = (relativePos2.x * tangent.y) - (relativePos2.y * tangent.x); // JVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra); FP num0 = ((rbntrb.x * body2.invInertiaWorld.M11) + (rbntrb.y * body2.invInertiaWorld.M21)) + (rbntrb.z * body2.invInertiaWorld.M31); FP num1 = ((rbntrb.x * body2.invInertiaWorld.M12) + (rbntrb.y * body2.invInertiaWorld.M22)) + (rbntrb.z * body2.invInertiaWorld.M32); FP num2 = ((rbntrb.x * body2.invInertiaWorld.M13) + (rbntrb.y * body2.invInertiaWorld.M23)) + (rbntrb.z * body2.invInertiaWorld.M33); rbntrb.x = num0; rbntrb.y = num1; rbntrb.z = num2; //JVector.Cross(ref rantra, ref relativePos1, out rantra); num0 = (rbntrb.y * relativePos2.z) - (rbntrb.z * relativePos2.y); num1 = (rbntrb.z * relativePos2.x) - (rbntrb.x * relativePos2.z); num2 = (rbntrb.x * relativePos2.y) - (rbntrb.y * relativePos2.x); rbntrb.x = num0; rbntrb.y = num1; rbntrb.z = num2; } } if (!treatBody1AsStatic) { kTangent += TSVector.Dot(ref rantra, ref tangent); } if (!treatBody2AsStatic) { kTangent += TSVector.Dot(ref rbntrb, ref tangent); } massTangent = FP.One / kTangent; restitutionBias = lostSpeculativeBounce; speculativeVelocity = FP.Zero; FP relNormalVel = normal.x * dvx + normal.y * dvy + normal.z * dvz; //JVector.Dot(ref normal, ref dv); if (Penetration > settings.allowedPenetration) { restitutionBias = settings.bias * (FP.One / timestep) * TSMath.Max(FP.Zero, Penetration - settings.allowedPenetration); restitutionBias = TSMath.Clamp(restitutionBias, FP.Zero, settings.maximumBias); // body1IsMassPoint = body2IsMassPoint = false; } FP timeStepRatio = timestep / lastTimeStep; accumulatedNormalImpulse *= timeStepRatio; accumulatedTangentImpulse *= timeStepRatio; { // Static/Dynamic friction FP relTangentVel = -(tangent.x * dvx + tangent.y * dvy + tangent.z * dvz); FP tangentImpulse = massTangent * relTangentVel; FP maxTangentImpulse = -staticFriction * accumulatedNormalImpulse; if (tangentImpulse < maxTangentImpulse) { friction = dynamicFriction; } else { friction = staticFriction; } } TSVector impulse; // Simultaneos solving and restitution is simply not possible // so fake it a bit by just applying restitution impulse when there // is a new contact. // modified by tiger, uncommmented. //if (relNormalVel < -FP.One && newContact) //{ // restitutionBias = TSMath.Max(-restitution * relNormalVel, restitutionBias); //} // added by seok //if (!newContact) if (!newContact || TSMath.Abs(relNormalVel *= restitution) < restitution) { relNormalVel = 0; } restitutionBias = TSMath.Max(-restitution * relNormalVel, restitutionBias); // Speculative Contacts! // if the penetration is negative (which means the bodies are not already in contact, but they will // be in the future) we store the current bounce bias in the variable 'lostSpeculativeBounce' // and apply it the next frame, when the speculative contact was already solved. if (penetration < -settings.allowedPenetration) { speculativeVelocity = penetration / timestep; lostSpeculativeBounce = restitutionBias; restitutionBias = FP.Zero; } else { lostSpeculativeBounce = FP.Zero; } impulse.x = normal.x * accumulatedNormalImpulse + tangent.x * accumulatedTangentImpulse; impulse.y = normal.y * accumulatedNormalImpulse + tangent.y * accumulatedTangentImpulse; impulse.z = normal.z * accumulatedNormalImpulse + tangent.z * accumulatedTangentImpulse; if (!treatBody1AsStatic) { body1.linearVelocity.x -= (impulse.x * body1.inverseMass); body1.linearVelocity.y -= (impulse.y * body1.inverseMass); body1.linearVelocity.z -= (impulse.z * body1.inverseMass); if (!body1IsMassPoint) { FP num0, num1, num2; num0 = relativePos1.y * impulse.z - relativePos1.z * impulse.y; num1 = relativePos1.z * impulse.x - relativePos1.x * impulse.z; num2 = relativePos1.x * impulse.y - relativePos1.y * impulse.x; FP num3 = (((num0 * body1.invInertiaWorld.M11) + (num1 * body1.invInertiaWorld.M21)) + (num2 * body1.invInertiaWorld.M31)); FP num4 = (((num0 * body1.invInertiaWorld.M12) + (num1 * body1.invInertiaWorld.M22)) + (num2 * body1.invInertiaWorld.M32)); FP num5 = (((num0 * body1.invInertiaWorld.M13) + (num1 * body1.invInertiaWorld.M23)) + (num2 * body1.invInertiaWorld.M33)); body1.angularVelocity.x -= num3; body1.angularVelocity.y -= num4; body1.angularVelocity.z -= num5; } } if (!treatBody2AsStatic) { body2.linearVelocity.x += (impulse.x * body2.inverseMass); body2.linearVelocity.y += (impulse.y * body2.inverseMass); body2.linearVelocity.z += (impulse.z * body2.inverseMass); if (!body2IsMassPoint) { FP num0, num1, num2; num0 = relativePos2.y * impulse.z - relativePos2.z * impulse.y; num1 = relativePos2.z * impulse.x - relativePos2.x * impulse.z; num2 = relativePos2.x * impulse.y - relativePos2.y * impulse.x; FP num3 = (((num0 * body2.invInertiaWorld.M11) + (num1 * body2.invInertiaWorld.M21)) + (num2 * body2.invInertiaWorld.M31)); FP num4 = (((num0 * body2.invInertiaWorld.M12) + (num1 * body2.invInertiaWorld.M22)) + (num2 * body2.invInertiaWorld.M32)); FP num5 = (((num0 * body2.invInertiaWorld.M13) + (num1 * body2.invInertiaWorld.M23)) + (num2 * body2.invInertiaWorld.M33)); body2.angularVelocity.x += num3; body2.angularVelocity.y += num4; body2.angularVelocity.z += num5; } } lastTimeStep = timestep; newContact = false; }
/// <summary> /// PrepareForIteration has to be called before <see cref="Iterate"/>. /// </summary> /// <param name="timestep">The timestep of the simulation.</param> public void PrepareForIteration(FP timestep) { TSVector dv = CalculateRelativeVelocity(); FP kNormal = FP.Zero; TSVector rantra = TSVector.zero; if (!treatBody1AsStatic) { kNormal += body1.inverseMass; if (!body1IsMassPoint) { TSVector.Cross(ref relativePos1, ref normal, out rantra); TSVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra); TSVector.Cross(ref rantra, ref relativePos1, out rantra); } } TSVector rbntrb = TSVector.zero; if (!treatBody2AsStatic) { kNormal += body2.inverseMass; if (!body2IsMassPoint) { TSVector.Cross(ref relativePos2, ref normal, out rbntrb); TSVector.Transform(ref rbntrb, ref body2.invInertiaWorld, out rbntrb); TSVector.Cross(ref rbntrb, ref relativePos2, out rbntrb); } } if (!treatBody1AsStatic) { kNormal += TSVector.Dot(ref rantra, ref normal); } if (!treatBody2AsStatic) { kNormal += TSVector.Dot(ref rbntrb, ref normal); } massNormal = FP.One / kNormal; tangent = dv - TSVector.Dot(dv, normal) * normal; tangent.Normalize(); FP kTangent = FP.Zero; if (treatBody1AsStatic) { rantra.MakeZero(); } else { kTangent += body1.inverseMass; if (!body1IsMassPoint) { TSVector.Cross(ref relativePos1, ref normal, out rantra); TSVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra); TSVector.Cross(ref rantra, ref relativePos1, out rantra); } } if (treatBody2AsStatic) { rbntrb.MakeZero(); } else { kTangent += body2.inverseMass; if (!body2IsMassPoint) { TSVector.Cross(ref relativePos2, ref tangent, out rbntrb); TSVector.Transform(ref rbntrb, ref body2.invInertiaWorld, out rbntrb); TSVector.Cross(ref rbntrb, ref relativePos2, out rbntrb); } } if (!treatBody1AsStatic) { kTangent += TSVector.Dot(ref rantra, ref tangent); } if (!treatBody2AsStatic) { kTangent += TSVector.Dot(ref rbntrb, ref tangent); } massTangent = FP.One / kTangent; restitutionBias = lostSpeculativeBounce; speculativeVelocity = FP.Zero; FP relNormalVel = TSVector.Dot(ref normal, ref dv); if (Penetration > settings.allowedPenetration) { restitutionBias = settings.bias * (FP.One / timestep) * TSMath.Max(FP.Zero, Penetration - settings.allowedPenetration); restitutionBias = TSMath.Clamp(restitutionBias, FP.Zero, settings.maximumBias); // body1IsMassPoint = body2IsMassPoint = false; } FP timeStepRatio = timestep / lastTimeStep; accumulatedNormalImpulse *= timeStepRatio; accumulatedTangentImpulse *= timeStepRatio; { // Static/Dynamic friction FP relTangentVel = -TSVector.Dot(ref tangent, ref dv); FP tangentImpulse = massTangent * relTangentVel; FP maxTangentImpulse = -staticFriction * accumulatedNormalImpulse; if (tangentImpulse < maxTangentImpulse) { friction = dynamicFriction; } else { friction = staticFriction; } } TSVector impulse; // Simultaneos solving and restitution is simply not possible // so fake it a bit by just applying restitution impulse when there // is a new contact. //同时求解和恢复是不可能的,所以当有新的接触时,仅仅应用恢复脉冲,有点虚假。 if (relNormalVel < -FP.One && newContact) { restitutionBias = TSMath.Max(-restitution * relNormalVel, restitutionBias); } // Speculative Contacts! // if the penetration is negative (which means the bodies are not already in contact, but they will // be in the future) we store the current bounce bias in the variable 'lostSpeculativeBounce' // and apply it the next frame, when the speculative contact was already solved. // 如果穿透是负的(这意味着物体还没有接触,但是它们将来会接触), // 我们将当前弹跳偏置存储在变量“lostSpeculativeBounce”中,并在下一个框架中应用它,此时投机接触已经解决。 if (penetration < -settings.allowedPenetration) { speculativeVelocity = penetration / timestep; lostSpeculativeBounce = restitutionBias; restitutionBias = FP.Zero; } else { lostSpeculativeBounce = FP.Zero; } impulse = normal * accumulatedNormalImpulse + tangent * accumulatedTangentImpulse; ApplyImpulse(ref impulse); lastTimeStep = timestep; newContact = false; }