One of the issue I’ve had with URP is that the application of realistic lighting values is only partial, relegated to light temperature.
Meanwhile HDRP has a variety of physicaly accurate light values, which can be extremely useful in getting the right lighting for an environment. Additionally skybox exposures and other values are physically accurate and there’s even a nifty table used so people can more easily use a realistic base line when constructing their environments.
I actually used the above video to help me improve my rendering in URP, and that showed me these values should be similar between the two.
Will the unification/cohabitation of URP and HDRP bring these properties to URP?
Currently there are a few differences between URP and HDRP when it comes to physical lighting. Both the URP and HDRP shaders support physically correct materials and lighting - but URP is not passing in lights that have an intensity reflective of real world physical lights.The plan for enabling physically accurate light ranges in URP needs a few things for there to be a good and solid workflow:
We need to migrate the controls for the HDRP lights down into core unity so they can be used by URP.
We need to add preexposure control to URP as when you have have physically correct light ranges you are going to blow up the output intensity. This adds some interesting workflow things as well for example if you add a ‘real’ sun light to the project but have not configured exposure properly then the scene will be really really washed out - it’s not great for usability and in HDRP there are a lot of questions from people about ‘why is my scene too bright / too dark’. URP should be easier to use due to it being the standard Unity renderer so we need to solve things like this.
We need to add the light shapes and light types that are in HDRP to URP so that you don’t need to do any hacks or similar to get lighting looking the same.The goal here is to unify the lighting between URP and HDRP to the point where you do not have to reauthor the lights if you migrate your project between the rendering backends.
Personally I think this problem can be solved with better default scenes and presets. But I do understand this problem, most people don’t have a grasp of HDR colors, Exposure and certain photography concepts. I even streamed a class on this once on picarto, using URP to explain how it should work.
I think a lot of new gamedevelopers aren’t aware of how the colors are being processed. And would recommend unity give classes or youtube videos explaining how the numbers work.
