The definitive guide to lighting in the High Definition Render Pipeline is now updated with the latest graphics capabilities in Unity 2021 LTS. This e-book was first published late last year as we announced previously in the forum to demonstrate the power of physically based lighting in HDRP for creating high-end lighting effects across PC and console games.
What’s been added?
New content has been added for Light Anchors, Clouds, Lens Flares, Dynamic Resolution, and ray tracing updates among many other small tweaks throughout the book.
Here’s a quick overview of the topics the e-book covers:
HDRP concepts, settings, cameras, and Volumes frameworks
Exposure, modes, physical camera settings, and formulas
Light units, types, properties, and IES Profiles
Creating natural-looking skyscapes with the Physically Based Sky system
Refining and modifying shadows, reflections, and real-time lighting effects to add depth to your scenes
Best practices for using the Rendering Debugger
Ray tracing and post-processing
Who is the guide for?
The guide is intended to be a foundational, advanced-level resource for technical artists, lighting artists, and developers working in Unity.
If you have any feedback or encounter problems accessing the file let us know in this thread
This guide helped me a lot to understand how to use lighting with HDRP.
I am currently working on a HDRP project with the objective of simulating real lights using IES files and being able to gather data on intensity, reflection and so on. But unfortunately there seems to be a slight difference between what I get through HDRP and what I got on my own data, the shape is overall the same but the distribution of intensity is a little off:
Can you describe how you’ve measured the intensity distribution in Unity compared to the official data ?
The shape indeed looks similar, maybe the issue is that there is some wrong “shift” in intensity happening ? Maybe a linear to gamma correction when reading out from Unity ?
Thanks for sharing those ideas, we took note for the 22 LTS update of the book for both topics.
In the meantime you can check this [forum post]( https://discussions.unity.com/t/833530 page-13#post-7940989) on how to create god rays.
For diffusion profiles, it’s usually eye balled. There is some physics involved behind the Radius value (in world space), but ultimately, it’s an artistic process because we use a very rough approximation (like everybody else). In any case, for 22 LTS there might be new features around this to cover in detail in the next book update.
Thanks!
I think there is indeed a gamma/linear conversion issue.
You’re creating tmpTexture as a linear texture, but temp2DTexture with the default width/height constructor, that by default creates a sRGB texture.
I suspect that this is the cause of the difference.
Small detail, but I doubt that the conversion to greyscale is needed, as ies are already greyscale with r=g=b, you could just output the value of the red channel.
Maybe I missed it, but perhaps in the next one, it would be nice to mark new/changed features as such for those who are already familiar with HDRP and want to drill exactly at the changes.
