izzy/UnrealEngineUWP
0
0
Fork 0
mirror of https://github.com/izzy2lost/UnrealEngineUWP.git synced 2026-03-26 18:15:20 -07:00
Code Issues Packages Projects Releases Wiki Activity

Back out of bad change to GPU partilce collision.

Browse Source 
[CL 2703031 by Simon Tovey in Main branch]
This commit is contained in:
Simon Tovey
2015-09-23 15:02:08 -04:00
committed by Simon.Tovey@epicgames.com
parent a2a4328b75
commit 5367557ecb
1 changed files with 7 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
Engine/Shaders/ParticleSimulationShader.usf
View File

@@ -245,8 +245,7 @@ void CollideWithDepthBuffer(
in float3 InVelocity,
in float3 Acceleration,
in float CollisionRadius,
in float Resilience,
inout float CollisionStop
in float Resilience
)
{
// Integration assuming no collision.
@@ -293,14 +292,6 @@ void CollideWithDepthBuffer(
//if (t_back >= 0 && t_front <= 1 && DistanceToPlane >= 0)
if (step(0, t_back) * step(t_front, 1) * step(0, DistanceToPlane))
{
//When the collision response is "Stop" the resilience is 0.0.
//In this case we mark the event so that all future updates of the particle motion are stopped.
//Prevents Stopped particles from continuing to move if they go off screen.
if (Resilience < 0.0001f)
{
CollisionStop = 1.0f;
}
// Separate velocity in to the components perpendicular and tangent to the collision plane.
float3 PerpVelocity = dot(MidVelocity,CollisionPlane.xyz) * CollisionPlane.xyz;
float3 TanVelocity = MidVelocity - PerpVelocity;
@@ -344,8 +335,7 @@ void CollideWithDistanceField(
in float3 InVelocity,
in float3 Acceleration,
in float CollisionRadius,
in float Resilience,
out float CollisionStop
in float Resilience
)
{
// Integration assuming no collision.
@@ -378,14 +368,6 @@ void CollideWithDistanceField(
//if (t_back >= 0 && t_front <= 1 && DistanceToPlane >= 0)
if (step(0, t_back) * step(t_front, 1) * step(0, DistanceToPlane))
{
//When the collision response is "Stop" the resilience is 0.0.
//In this case we mark the event so that all future updates of the particle motion are stopped.
//Prevents Stopped particles from continuing to move if they go off screen.
if (Resilience < 0.0001f)
{
CollisionStop = 1.0f;
}
// Separate velocity in to the components perpendicular and tangent to the collision plane.
float3 PerpVelocity = dot(MidVelocity,CollisionPlane.xyz) * CollisionPlane.xyz;
float3 TanVelocity = MidVelocity - PerpVelocity;
@@ -416,17 +398,6 @@ void CollideWithDistanceField(
#endif
float PackRelativeTimeAndCollisionStop(in float RelativeTime, in float CollisionStop)
{
return CollisionStop > 0.0f ? -RelativeTime : RelativeTime;
}
float UnpackRelativeTimeAndCollisionStop(in float PackedValue, out float CollisionStop)
{
CollisionStop = PackedValue < 0.0f ? 1.0f : 0.0f;
return abs(PackedValue);
}
void PixelMain(
in FShaderInterpolants Interpolants,
out float4 OutPosition : SV_Target0,
@@ -448,14 +419,7 @@ void PixelMain(
// Position.w holds the relative time of the particle.
float3 Position = PositionSample.xyz;
float CollisionStop;
float RelativeTime = UnpackRelativeTimeAndCollisionStop(PositionSample.w, CollisionStop);
RelativeTime += DeltaSeconds * TimeScale;
//Everything other that particle aging should stop if we have collision stop.
float CollisionAdjustedDeltaSeconds = CollisionStop > 0.0f ? 0.0f : DeltaSeconds;
float RelativeTime = PositionSample.w + DeltaSeconds * TimeScale;
// Sample the attribute curve.
const float2 AttributeCurveTexCoord = Simulation.AttributeCurve.xy +
@@ -489,7 +453,7 @@ void PixelMain(
Force += ComputeAttractionForce(Position.xyz);
// Compute the acceleration to apply to the particle this frame.
float3 Acceleration = Force * CollisionAdjustedDeltaSeconds;
float3 Acceleration = Force * DeltaSeconds;
#if DEPTH_BUFFER_COLLISION || DISTANCE_FIELD_COLLISION
// We need to look up render attributes for this particle to figure out how big it is.
@@ -522,8 +486,7 @@ void PixelMain(
Velocity.xyz,
Acceleration,
CollisionRadius,
Resilience,
CollisionStop
Resilience
);
#elif DISTANCE_FIELD_COLLISION
@@ -537,8 +500,7 @@ void PixelMain(
Velocity.xyz,
Acceleration,
CollisionRadius,
Resilience,
CollisionStop
Resilience
);
#else
@@ -554,7 +516,7 @@ void PixelMain(
// Store the new position, time, and velocity for the particle.
OutPosition.xyz = NewPosition + OrbitVelocity * DeltaSeconds + PositionOffsetAndAttractorStrength.xyz;
OutPosition.w = PackRelativeTimeAndCollisionStop(RelativeTime, CollisionStop);
OutPosition.w = RelativeTime;
OutVelocity.xyz = NewVelocity;
OutVelocity.w = TimeScale;
}