So i need to convert this function to C++, Hue Shift of the material editor:
There seems to be no corresponding function in the engine for the HueShift, because its a material function that is made of other functions, of course…
So i tried looking for the RotateAboutAxis function and gives me this super weird and obscure function that seems to need a material:
UMaterialExpressionRotateAboutAxis()
What should be my course of action in this situation?
What do you need the function to change in C++? Are you planning on hue shifting a UTexture or FVector? Are you tying to get the same functionality out of the material editor and into a game world ready function?
If you’ve got an FLinearColor structure you can use the “LinearRGBToHSV” method then change the R value (Hue).
Thanks.
Basically, i use the hue shift instead of a 3 Per Instance Custom Data to change the color of my Units.
So i start with a color Green and hue shift with just 1 PICD. That seems to me that it is better in performance, 1 PICD vs 3 PICD.
But the problem is that i need to calculate the hue shift outside so that i SetCustomDataValue() in C++ with the right colors. You get me 
?
I tried that but never get accurate values.
The hue shift requires a color input and then the hue shift float value.
What would the LinearRGBToHSV values correspond to?
In my case my hue shift has a Green input: 0, 1, 0 
So a float of 0.65 shift, would turn it into a reddish color 
.
So what would be the corresponding input color and hue shift that would match the LinearRGBToHSV?
This is quite confusing for my adhd brain.
The Hue is represented as an angle between 0 and 360, so it’s 0.65x360 that you want to add:
FLinearColor hsv = col.LinearRGBToHSV();
hsv.R = fmod( hsv.R + ( 0.65 * 360.0f ) , 360.0f );
FLinearColor rgb = hsv.HSVToLinearRGB();
ahh i didnt noticed the difference was so small.
So its solved, thanks so much 
Now sometimes in my project i need to reverse and instead of getting the Target Color after the hueshift, I need to get the hueshift between 2 colors.
Idk if this is even possible. I tried a lot, but all i get is weird results.
FLinearColor ReferenceColor = FLinearColor::Green;
FLinearColor ResultColor = UCampaignBlueprintFunctionLibrary::GetColorFromHueShift(0.65, ReferenceColor);
//got the result color that in this case is a reddish color from the hueshift 0.65
float Hue2 = UCampaignBlueprintFunctionLibrary::GetHueShiftBetweenColors(ResultColor, ReferenceColor);
//now im trying to get that hueshift given only the 2 colors. here the output should be 0.65. Though im getting 0.35
FLinearColor UCampaignBlueprintFunctionLibrary::GetColorFromHueShift( float HueShift, FLinearColor ReferenceColor){
FLinearColor hsv = ReferenceColor.LinearRGBToHSV();
hsv.R = fmod(hsv.R + (HueShift * 360.0f), 360.0f);
FLinearColor rgb = hsv.HSVToLinearRGB();
return rgb;
}
float UCampaignBlueprintFunctionLibrary::GetHueShiftBetweenColors( FLinearColor ReferenceColor, FLinearColor TargetColor) {
FLinearColor hsvReference = ReferenceColor.LinearRGBToHSV();
FLinearColor hsvTarget = TargetColor.LinearRGBToHSV();
// Extract hue values in degrees
float hueReference = hsvReference.R; // Reference hue in degrees
float hueTarget = hsvTarget.R; // Target hue in degrees
// Calculate hue shift
float hueShift = fmod((hueTarget - hueReference + 360.0f), 360.0f) / 360.0f;
return hueShift;
}
Try this:
float hueShift = (( hueTarget > hueReference ) ? 360.0f-(hueTarget-hueReference) : (hueReference-hueTarget) ) / 360.0f;
The results you will have been getting will probably be the negative amount.
Thanks a lot. This worked perfectly. i spent like almost an hour trying to figure this out by myself. Even chatgpt was not doing it right. Thanks.