Hi! Thank you very much for these tutorials :D. I was wondering where can I learn the code used in Unreal Engine 4 materials custom node. I am looking for a full guide, if someone exsists. I was trying to recreate a blackhole effect, like the one in the interstellar movie. Something like this: Shader - Shadertoy BETA
but I failed miserably.
Thank you again!
Thanks for the heads up! 4.21 has that as a “bug fix”:
Bug Fix: Replaced automatic virtual shader directory mapping with manual approach in StartupModule(). It should reduce the amount of directory exists queries at Editor startup.
The custom node uses HLSL so that’d be a good place to start. You can also check our Custom Shaders tutorial for information on how the HLSL is generated.
Projectname.h (Derive of FDefaultGameModuleImpl to override StartupModule())
#pragma once
#include “CoreMinimal.h”
class FModifiedDefaultModuleImpl
: public FDefaultGameModuleImpl
{
virtual void StartupModule() override;
};
Projectname.cpp ( replace FDefaultGameModuleImpl with your derrived class, implement the function StartupModule() and call AddShaderSourceDirectoryMapping() to include your projects /Shader/ directory)
The filter adds some significant flickering/jitter, especially around the thin parts of of leaves when pulling the camera back a bit.
Research suggested that going into the material, in this case PP_Kuwahara → Post Processing Material → Blendable Location, and setting Before Tonemapping can help for certain post processing effects, but didn’t do much for me in this case.
Turning off Temporal Anti-Aliasing, now accessible only in the project settings, does fix the jitter, but the overall scene doesn’t look as good when moving around.
This post links to a PowerPoint from Epic about the development of TemporalAA, which suggests using sharpening, blurring, or noise to compensate.
Adding a Gaussian Depth of Field to the PostProcessVolume with just a bit of far blur looks best to me. Lots of DoF settings available, helpful for retaining edges/details.
Thanks very much for putting this together! Just wanted to dump my info here for others.
Great tutorial, thank you!
Looks like the variance is miscalculated, though. You have to get the mean value first, then get the sum of the squared differences (pixelvalue - meanvalue), then divide this sum by the number of samples.
for (int x = Range.x; x <= Range.y; x++)
{
for (int y = Range.z; y <= Range.w; y++)
{
float2 Offset = mul(float2(x, y) * TexelSize, RotationMatrix);
float3 PixelColor = SceneTextureLookup(UV + Offset, 14, false).rgb;
Mean += PixelColor;
Samples++;
}
}
Mean /= Samples;
for (int x = Range.x; x <= Range.y; x++)
{
for (int y = Range.z; y <= Range.w; y++)
{
float2 Offset = mul(float2(x, y) * TexelSize, RotationMatrix);
float3 PixelColor = SceneTextureLookup(UV + Offset, 14, false).rgb;
Variance += (PixelColor - Mean) * (PixelColor - Mean);
}
}
Variance = Variance / Samples;
What if I’d like to add a full vertex and pixel shader? I’ve seen some plugins as examples in C++ but unfortunately I can’t figure It out how to make them work and how to link the shaders
Something like that: