Files
2025-05-29 22:31:40 +03:00

112 lines
4.2 KiB
C#

#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
using UnityEngine;
using Unity.Jobs;
using Unity.Collections;
using Unity.Collections.LowLevel.Unsafe;
using Unity.Mathematics;
using Unity.Burst;
using System.Collections;
namespace Obi
{
public class BurstAerodynamicConstraintsBatch : BurstConstraintsBatchImpl, IAerodynamicConstraintsBatchImpl
{
private NativeArray<float> aerodynamicCoeffs;
public BurstAerodynamicConstraintsBatch(BurstAerodynamicConstraints constraints)
{
m_Constraints = constraints;
m_ConstraintType = Oni.ConstraintType.Aerodynamics;
}
public void SetAerodynamicConstraints(ObiNativeIntList particleIndices, ObiNativeFloatList aerodynamicCoeffs, int count)
{
this.particleIndices = particleIndices.AsNativeArray<int>();
this.aerodynamicCoeffs = aerodynamicCoeffs.AsNativeArray<float>();
m_ConstraintCount = count;
}
public override JobHandle Initialize(JobHandle inputDeps, float substepTime)
{
return inputDeps;
}
public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
{
var projectConstraints = new AerodynamicConstraintsBatchJob()
{
particleIndices = particleIndices,
aerodynamicCoeffs = aerodynamicCoeffs,
positions = solverImplementation.positions,
velocities = solverImplementation.velocities,
normals = solverImplementation.normals,
wind = solverImplementation.wind,
invMasses = solverImplementation.invMasses,
deltaTime = substepTime
};
return projectConstraints.Schedule(m_ConstraintCount, 32, inputDeps);
}
public override JobHandle Apply(JobHandle inputDeps, float substepTime)
{
return inputDeps;
}
[BurstCompile]
public struct AerodynamicConstraintsBatchJob : IJobParallelFor
{
[ReadOnly] public NativeArray<int> particleIndices;
[ReadOnly] [NativeDisableParallelForRestriction] public NativeArray<float> aerodynamicCoeffs;
[ReadOnly] public NativeArray<float4> positions;
[ReadOnly] public NativeArray<float4> normals;
[ReadOnly] public NativeArray<float4> wind;
[ReadOnly] public NativeArray<float> invMasses;
[NativeDisableContainerSafetyRestriction]
public NativeArray<float4> velocities;
[ReadOnly] public float deltaTime;
public void Execute(int i)
{
int p = particleIndices[i];
float area = aerodynamicCoeffs[i * 3];
float dragCoeff = aerodynamicCoeffs[i * 3 + 1];
float liftCoeff = aerodynamicCoeffs[i * 3 + 2];
if (invMasses[p] > 0)
{
float4 relVelocity = velocities[p] - wind[p];
float rvSqrMag = math.lengthsq(relVelocity);
if (rvSqrMag < BurstMath.epsilon)
return;
float4 rvNorm = relVelocity / math.sqrt(rvSqrMag);
// calculate surface normal (always facing wind)
float4 surfNormal = normals[p] * math.sign(math.dot(normals[p], rvNorm));
// aerodynamic_factor was originally multiplied by air_density. The density is now premultiplied in lift and drag.
float aerodynamicFactor = 0.5f * rvSqrMag * area;
float attackAngle = math.dot(surfNormal,rvNorm);
float3 liftDirection = math.normalizesafe(math.cross(math.cross(surfNormal.xyz, rvNorm.xyz), rvNorm.xyz));
//drag:
velocities[p] += (-dragCoeff * rvNorm +
// lift:
liftCoeff * new float4(liftDirection.xyz,0)) *
// scale
attackAngle * math.min(aerodynamicFactor * invMasses[p] * deltaTime, 1000);
}
}
}
}
}
#endif