Physical Starlight and Atmosphere Addon for 2.9 (v1.3)

yeah I find those also a tick confusing to work with.
True with a camera based on the day you set the exposure iso etc all that
but does the sky add on have to be that difficult to use?

@martinsh @karlis.upitis

could you guys provide some answers?

Hi there, when I do a volume shader PSA 1.3 still puts its node on the surface input in ‘material output’ resulting in a non looking good volume. This and transparency are a big issue at the moment. Is it possible to get presets based on the scene/project? (as well as the current global system)
My old question about preset system was about the ability to have many different lighting situation in the same file, now if I save 10 presets I’m going to find them in new projects as well which is not ideal.
If I have a client that’s asking for many different lighting conditions/time of day having the possibility of saving them on the project file would be amazing.
Thanks a lot for your work

@renderthings I guess the add-on makers are not checking this forum

Hi!
Wow, this is a good point, thank you for pointing out. It should be dark like first image.
1.2 was a step in the right direction in terms of “physicality” but I went too far and tinkered with exposure value without notifying the user :slight_smile:
1.3 brought back the default “magicality” and added button for physical values. but now it seems I have broken the night values.
I was about to go through mie scattering algortihm once more, but I will revisit luminance accuracy first.

Hi,
So this topic actually deserves an article alone. You see, as an artist you usually work with what looks correct and so far Blender has been a very artist-friendly tool. Values for materials and lights were mainly unitless and we used to work in rather shallow dynamic range (most even from 0.0 to 1.0)
Now, last few years have been “physically based rendering” years in CG industry. Blender moves in this direction too. Suddenly you have to think like a photographer and optics scientist :smiley:
It is a large leap for someone who just want to make things that look right.

PSA is attempt to bridge the gap, it is an ongoing experiment and sort of community assisted project (as you see here in comments)

So to answer to your questions:

yes and no.
yes it is more complicated because you will have to know actual light source properties like watts, temperature and luminous efficacy (instead of intensity and RGB color) to get the light shine correctly. You might need to use PBR materials too. And then you have to use correct camera exposure parameter and tone mapping because now your shade luminance can be a value of 100 and lit surface - 3000.

no - not problematic. If you go through the process few times, you will notice the increased render quality and reduced time spent on tweaking things. Stuff will just look right out of the box.

Hi,

Use -6 Blender exposure (~ 16 EV100) with any physical sky texture like Nishita, Hosek etc.
It is a default “Sunny” camera preset :slight_smile:

179° (horizon) and 70° are not that different in terms of sky “dome” illuminance. (It is a different story about sun disk irradiance though)
A fine camera sensor can capture scene when sun is at zenith and scene where sun is nearing horizon with same exposure parameter.

You can check it with new Nishita Sky or LuxCore Render sky models.

Blender Nishita Sky (70 degrees and 179 degrees)
Nishita Sky is analytic model (measured with instruments) which means that these provide real world values. It is a good test subject for “physicality”.

The big difference begins when sun is below horizon.

Added to backlog, it will be fixed in the upcoming update.

Transparency is being addressed. It works super with Eevee, but cycles is tricky as it needs alpha input field.

this is a really useful feature, we are looking into it.

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Awesome news as always! Thanks for your support

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I am somewhat thinking about my students here adapting to this as beginners - while I agree that I also was used to a the rather shallow dynamic range.

sofar making a sun light simply stronger and tweaking interior lights based on the desired effect or reference photo served well - using your well eye to judge.

It seems to me with a sky model like yours people need to be a lot more conscious about the light strengths and then use the exposure slider to adjust in addition.

Even things like this I dont know if many know it - I did not.

Maybe there should be a public article / guide for users to make the transition.

I could see know why and how your add-on would work well also with the photographer add-on etc.

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Summary

Well, I am sadly disappointed here. I logged in this morning and found that you released the 1.3 update, which I am very happy about, and eager to try!

So I went to BlenderMarket, tryed to download the update, as I ddi with 1.2. After signing in with them, they won’t admit that I ever bought this in the first place, so now they want to charge me $58 US for software I already purchased months ago, and should be able to get an update for.

I will be very happy to test this release when I can afford to purchase a new copy., or when I can actually download an update. Everything lookas great and I really appreciate all that you have done on this. I just wanted to let you know Blender Market is being a pain on updates. Maybe you can get results from them.

UPDATE: I was able to finally locate the update file, even though BlenderMarket continues to not list the purchase I made. Eagerly looking forward to playing with the new settings. :grin: :smiley: :grinning:

Blender Market really needs to get their interface together… :japanese_ogre: :rage:

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I agree so much! Whole concept of working in higher dynamic range can be very difficult to comprehend as it involves so many variables that interact in the end result.
I teach physical lighting and materials in college and university using Blender, I have now a rather solid understanding of it. I would be happy to write an article.

@ martinsh & Karlisupitis;

After a quick test of the update, I have to say: Thank you so very very much! The feature is easy to use, does not bog down my cpu or gpu, and works beautifully. Absolutely everything I was looking for!

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this would be wonderful. my interior design students love blender actually (besides those who want to use enscape because they want quick results). such an article would be amazing.

maybe academically we could collaborate or I invite you for a presentation to my class.
we would need to see how we do the time difference.
in case this would be of interest to you.

Hi martinsh,
thanks for your reply!

Oh, I didn’t know that, maybe when I take pictures other factors are involved (like shadows, buildings around, etc)…or my camera has not so fine sensor :smile:
As @ cekuhnen said, an article would be very useful.
Best
Ciro

@renderthings Yeah they offer a different workflow or process which I think most of us are not used to.

It is not dark magic but I think they understand they underlying physics better than us at the moment.

I start to realize that approaching this from a photography standpoint helps but in real life I just make a photo and all is set (lights sun etc dont change) it is captured as is by how the camera is set-up.

In CG this can be a little more complicating.

particularly with Photographer this gets very interesting

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Hi @cekuhen,
Yes, probably the rule should be understand the logic that stands behind these physically based approaches (that’s what in someway I asked to martinsh previously) and than look if they would help you or not with your workflow.
Using a renderer from a photographic approach may lead to a complicate life, but it gives you less “guessing” and more references with the real world, so for someone may be advantageous to adopt.
I use the Photographer addon and I love it, but I have not found a way to use it properly with Physical Starlight and Atmosphere, I think the uderline approach is a bit different regarding the exposure.

Glad I am not alone :wink:

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@martinsh when do you plan to add ozone layer? Will it come with clouds?

Hi @martinsh
Great add-on, made my life so much easier since just starting with blender and already setting some decent lighting results in eevee!

I came upon a little problem, that might not be too hard to solve, but to be honest, I think I am still too much of a beginner to know where I have to tweet the nodes to get the desired output.

I got these types of animated renderings (below), the background should be a simple fade from this yellowish orange to almost white without the atmospheric stripe in the back, to lift the attention off the border of the model…

For other perspectives this is not the problem, because the point of view is low enough…

Do you guys know how I could achieve this, keeping the light settings as is (In either nodes or the sidebar)? Sorry for the trouble, probably a beginners-question… :confused:

thanks, Julian