Distortion-aware depth fade

[Efron]

@

@EvoPulseGaming

Updated code:

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Custom node input parameters:
//float2 Refraction; R = IOR, the same as material refraction input, G = Refraction Bias, the same as in material/material instance settings.
//float3 MaterialNormal;
//float DepthFadeDistance
//float Opacity

// Custom node output:
//X,Y= Distorted Screen UV,
//Z=Distorted Scene Depth,
//W= Distortion-aware depth fade.
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Tweakable parameters
#define DIVDELTA 0.0000001 // Used to avoid division by zero. Should be kept at something low. Makes no visible difference.
#define USE_MIRRORED_WRAP_EDGES 0 // Distortion edge mirroring code by Kalle_H
#define MATCH_CLIP_CODE 1 // Matches a certain threshold in original code. Should be left at 1 preferably.
#define DEBUG_SCENE_RECT 0 // Debugs scene color size. Custom node will return (Min.X,Min.Y,Max.X,Max.Y)
#define DEBUG_DISTORTION 0 // Debugs distortion. Custom node will return (Distortion.X,Distortion.Y,UncorrectedDistortion.X,UncorrectedDistortion.Y)
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

static const float OffsetFudgeFactor = 0.00023;

//Gets view parameters for distortion
float4 DistortionParams=float4(
GetCotanHalfFieldOfView().r,
ResolvedView.ViewSizeAndInvSize.r/ResolvedView.ViewSizeAndInvSize.g,
ResolvedView.ViewSizeAndInvSize.r,
ResolvedView.ViewSizeAndInvSize.g
);

//Transforms either tangent or world normal into view space
#if MATERIAL_TANGENTSPACENORMAL
half3 ViewNormal = normalize(TransformTangentVectorToView(Parameters, Normal));
#else
half3 ViewNormal = normalize(TransformWorldVectorToView(Normal));
#endif

//Calculates Distortion from material normals.
#if REFRACTION_USE_PIXEL_NORMAL_OFFSET
half3 ViewVertexNormal = TransformTangentVectorToView(Parameters, float3(0, 0, 1));

// Treat Refraction of 1 as no refraction, to be consistent with IOR mode
float2 Distortion = (ViewVertexNormal.xy - ViewNormal.xy) * (Refraction.x - 1);
#else
// we assume the camera is in air
float AirIOR = 1.0f;
float2 Distortion = ViewNormal.xy * (Refraction.x - AirIOR);
#endif

// Should match clip in original code. Might make sense to branch.
FLATTEN if (dot(Distortion, Distortion) < 0.00001)
{
Distortion*=0;
}

// Prevent silhouettes from geometry that is in front of distortion from being seen in the distortion
float2 NDC = (Parameters.ScreenPosition.xy /Parameters.ScreenPosition.w);
float2 ScreenUV = NDC * ResolvedView.ScreenPositionScaleBias.xy + ResolvedView.ScreenPositionScaleBias.wz;

//Fix for Fov and aspect.
float InvTanHalfFov = DistortionParams.x;
float Ratio = DistortionParams.y;
float2 FovFix = float2(InvTanHalfFov,Ratio*InvTanHalfFov);
Distortion *= DistortionParams.zw * float2(OffsetFudgeFactor,-OffsetFudgeFactor) * FovFix;

// Sample depth at distortion offset
float2 NewBufferUV = ScreenUV + Distortion;

#if (ES2_PROFILE || ES3_1_PROFILE)
float DistortSceneDepth = ConvertFromDeviceZ(Texture2DSampleLevel(SceneDepthTexture, SceneDepthTextureSampler, NewBufferUV, 0).r);
#else
float DistortSceneDepth = CalcSceneDepth(NewBufferUV);
#endif // (ES2_PROFILE || ES3_1_PROFILE)

// Soft thresholding
float Bias = -Refraction.y;
float Range = clamp(abs(Bias * 0.5f), 0, 50);
float Z = DistortSceneDepth;
float ZCompare = Parameters.ScreenPosition.w;
float InvWidth = 1.0f / max(1.0f, Range );

#if DEBUG_DISTORTION
float2 UncorrectedDistortion=Distortion;
#endif

Distortion *= saturate((Z - ZCompare) * InvWidth + Bias);

NewBufferUV = ScreenUV.xy + Distortion;

//optionally toggle edge mirroring instead of clamping
#if !USE_MIRRORED_WRAP_EDGES
// If we’re about to sample outside the valid View.BufferBilinearUVMinMax, set to 0 distortion.
FLATTEN if ( NewBufferUV.x < View.BufferBilinearUVMinMax.x || NewBufferUV.x > View.BufferBilinearUVMinMax.z ||
NewBufferUV.y < View.BufferBilinearUVMinMax.y || NewBufferUV.y > View.BufferBilinearUVMinMax.w )
{
NewBufferUV = ScreenUV.xy;
}
#else
// Apply mirror distortion if NewBufferUV is outside of borders.
if (NewBufferUV.x < View.BufferBilinearUVMinMax.x || NewBufferUV.x > View.BufferBilinearUVMinMax.z)
Distortion.x = -Distortion.x;
if (NewBufferUV.y < View.BufferBilinearUVMinMax.y || NewBufferUV.y > View.BufferBilinearUVMinMax.w)
Distortion.y = -Distortion.y;
NewBufferUV = ScreenUV + Distortion;
#endif //USE_MIRRORED_WRAP_EDGES

//Sample scene depth again with adjusted distortion UVs
#if (ES2_PROFILE || ES3_1_PROFILE)
DistortSceneDepth = ConvertFromDeviceZ(Texture2DSampleLevel(SceneDepthTexture, SceneDepthTextureSampler, NewBufferUV, 0).r);
#else
DistortSceneDepth = CalcSceneDepth(NewBufferUV);
#endif // (ES2_PROFILE || ES3_1_PROFILE)

// returs result with debug option
#if DEBUG_SCENE_RECT
return View.BufferBilinearUVMinMax;
#elif DEBUG_DISTORTION
return float4(Distortion,UncorrectedDistortion);
#else
return float4(
NewBufferUV,
DistortSceneDepth,
Opacity * saturate((DistortSceneDepth - ZCompare) / max(DepthFadeDistance, DIVDELTA))
);
#endif
///////////////////////////////////////////////////////////////////////////////////////////////////////////

Could you please post the material graph?
it is confuse that how to use this node thx.

[Deathrey (DeathreyCG)]

@Efron

@

Could you please post the material graph?
it is confuse that how to use this node thx.

Whatever is contained in this thread is pretty ancient and is no longer necessary with addition of Single Layer water shading model into the engine as of recently.

[Efron]

Whatever is contained in this thread is pretty ancient and is no longer necessary with addition of Single Layer water shading model into the engine as of recently.

I just need a reference. But it lost the picture.
Do you know how to solute this problem now?

[KristyDoe]

What is contained in this thread is not “ancient” with the addition of Single Layer Water. Single Layer Water doesn’t appear to have any blur affect like what you can achieve with Translucency Blend mode + the SpiralBlur-SceneTexture node. This blurring is crucial for creating materials like Gels or fogged glass.

The images are probably long-gone, but if you sign-in to Git-Hub with a Epic-linked github account you should be able to download the code, though it doesn’t appear to have been updated for some time.

[KristyDoe]

@EvoPulseGaming

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Custom node input parameters:
//float2 Refraction; R = IOR, the same as material refraction input, G = Refraction Bias, the same as in material/material instance settings.
//float3 MaterialNormal;
//float DepthFadeDistance
//float Opacity

// Custom node output:
//X,Y= Distorted Screen UV,
//Z=Distorted Scene Depth,
//W= Distortion-aware depth fade.
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Tweakable parameters
#define DIVDELTA 0.0000001 // Used to avoid division by zero. Should be kept at something low. Makes no visible difference.
#define USE_MIRRORED_WRAP_EDGES 0 // Distortion edge mirroring code by Kalle_H
#define MATCH_CLIP_CODE 1 // Matches a certain threshold in original code. Should be left at 1 preferably.
#define DEBUG_SCENE_RECT 0 // Debugs scene color size. Custom node will return (Min.X,Min.Y,Max.X,Max.Y)
#define DEBUG_DISTORTION 0 // Debugs distortion. Custom node will return (Distortion.X,Distortion.Y,UncorrectedDistortion.X,UncorrectedDistortion.Y)
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

static const float OffsetFudgeFactor = 0.00023;

//Gets view parameters for distortion
float4 DistortionParams=float4(
GetCotanHalfFieldOfView().r,
ResolvedView.ViewSizeAndInvSize.r/ResolvedView.ViewSizeAndInvSize.g,
ResolvedView.ViewSizeAndInvSize.r,
ResolvedView.ViewSizeAndInvSize.g
);

//Transforms either tangent or world normal into view space
#if MATERIAL_TANGENTSPACENORMAL
half3 ViewNormal = normalize(TransformTangentVectorToView(Parameters, Normal));
#else
half3 ViewNormal = normalize(TransformWorldVectorToView(Normal));
#endif

//Calculates Distortion from material normals.
#if REFRACTION_USE_PIXEL_NORMAL_OFFSET
half3 ViewVertexNormal = TransformTangentVectorToView(Parameters, float3(0, 0, 1));

// Treat Refraction of 1 as no refraction, to be consistent with IOR mode
float2 Distortion = (ViewVertexNormal.xy - ViewNormal.xy) * (Refraction.x - 1);
#else
// we assume the camera is in air
float AirIOR = 1.0f;
float2 Distortion = ViewNormal.xy * (Refraction.x - AirIOR);
#endif

// Should match clip in original code. Might make sense to branch.
FLATTEN if (dot(Distortion, Distortion) < 0.00001)
{
Distortion*=0;
}

// Prevent silhouettes from geometry that is in front of distortion from being seen in the distortion
float2 NDC = (Parameters.ScreenPosition.xy /Parameters.ScreenPosition.w);
float2 ScreenUV = NDC * ResolvedView.ScreenPositionScaleBias.xy + ResolvedView.ScreenPositionScaleBias.wz;

//Fix for Fov and aspect.
float InvTanHalfFov = DistortionParams.x;
float Ratio = DistortionParams.y;
float2 FovFix = float2(InvTanHalfFov,Ratio*InvTanHalfFov);
Distortion *= DistortionParams.zw * float2(OffsetFudgeFactor,-OffsetFudgeFactor) * FovFix;

// Sample depth at distortion offset
float2 NewBufferUV = ScreenUV + Distortion;

#if (ES2_PROFILE || ES3_1_PROFILE)
float DistortSceneDepth = ConvertFromDeviceZ(Texture2DSampleLevel(SceneDepthTexture, SceneDepthTextureSampler, NewBufferUV, 0).r);
#else
float DistortSceneDepth = CalcSceneDepth(NewBufferUV);
#endif // (ES2_PROFILE || ES3_1_PROFILE)

// Soft thresholding
float Bias = -Refraction.y;
float Range = clamp(abs(Bias * 0.5f), 0, 50);
float Z = DistortSceneDepth;
float ZCompare = Parameters.ScreenPosition.w;
float InvWidth = 1.0f / max(1.0f, Range );

#if DEBUG_DISTORTION
float2 UncorrectedDistortion=Distortion;
#endif

Distortion *= saturate((Z - ZCompare) * InvWidth + Bias);

NewBufferUV = ScreenUV.xy + Distortion;

//optionally toggle edge mirroring instead of clamping
#if !USE_MIRRORED_WRAP_EDGES
// If we’re about to sample outside the valid View.BufferBilinearUVMinMax, set to 0 distortion.
FLATTEN if ( NewBufferUV.x < View.BufferBilinearUVMinMax.x || NewBufferUV.x > View.BufferBilinearUVMinMax.z ||
NewBufferUV.y < View.BufferBilinearUVMinMax.y || NewBufferUV.y > View.BufferBilinearUVMinMax.w )
{
NewBufferUV = ScreenUV.xy;
}
#else
// Apply mirror distortion if NewBufferUV is outside of borders.
if (NewBufferUV.x < View.BufferBilinearUVMinMax.x || NewBufferUV.x > View.BufferBilinearUVMinMax.z)
Distortion.x = -Distortion.x;
if (NewBufferUV.y < View.BufferBilinearUVMinMax.y || NewBufferUV.y > View.BufferBilinearUVMinMax.w)
Distortion.y = -Distortion.y;
NewBufferUV = ScreenUV + Distortion;
#endif //USE_MIRRORED_WRAP_EDGES

//Sample scene depth again with adjusted distortion UVs
#if (ES2_PROFILE || ES3_1_PROFILE)
DistortSceneDepth = ConvertFromDeviceZ(Texture2DSampleLevel(SceneDepthTexture, SceneDepthTextureSampler, NewBufferUV, 0).r);
#else
DistortSceneDepth = CalcSceneDepth(NewBufferUV);
#endif // (ES2_PROFILE || ES3_1_PROFILE)

// returs result with debug option
#if DEBUG_SCENE_RECT
return View.BufferBilinearUVMinMax;
#elif DEBUG_DISTORTION
return float4(Distortion,UncorrectedDistortion);
#else
return float4(
NewBufferUV,
DistortSceneDepth,
Opacity * saturate((DistortSceneDepth - ZCompare) / max(DepthFadeDistance, DIVDELTA))
);
#endif
///////////////////////////////////////////////////////////////////////////////////////////////////////////

There is no material graph, this is custom code for a Custom Code node. Right-click your graph, start typing ‘custom’, and then drop the code in.

[KristyDoe]

All that being said, the custom-node code appears to still be returning depth-fade without being corrected.

Imgur: The magic of the Internet Here’s my setup and my results. I previously had a standard DepthFade node. The A channel of the output runs out to where this was previously connected, Normal input is the final normals before the Material node, Refraction is just turning my previous refraction parameter into a vec2 with 0 for the bias - the same as my material bias’ setting.

I’ll attempt to sift through the code and see if I can spot what’s wrong, but unless it’s a simple syntax error or matter of the wrong output being connected, it will likely be beyond me.

Update: I had opacity set to 0 when it should have been set to 1, all is working with the custom code now, it should be good to go.