Why I Don't Like PBR

[AmeliaJ08]

25 minutes ago, Arielle Popstar said:

It is all quite relative though isn't it. Those running high end cards of course don't think the card is adequate but to someone with an older card or relying on an Intel integrated video, it would be quite an affordable boost upwards. 

Yes, very true.

 

[Love Zhaoying]

Not sure which PBR thread this belongs in, so putting it here:

Yesterday I finally saw a situation where, if I rez a legacy build, it is almost completely dark inside (at certain shared environment times) with my current graphics settings under PBR.

D'oh!

This is a Peeve (and probably belongs in the Peeve thread) because, anyone visiting, or even I, must override the default settings so they aren't sitting in the dark.

I think that I missed this because, when testing PBR in my "cavern", I had some reflection probes setup that made it "not dark".

..Peeved.

[Scylla Rhiadra]

1 hour ago, Love Zhaoying said:

Not sure which PBR thread this belongs in, so putting it here:

Yesterday I finally saw a situation where, if I rez a legacy build, it is almost completely dark inside (at certain shared environment times) with my current graphics settings under PBR.

D'oh!

This is a Peeve (and probably belongs in the Peeve thread) because, anyone visiting, or even I, must override the default settings so they aren't sitting in the dark.

I think that I missed this because, when testing PBR in my "cavern", I had some reflection probes setup that made it "not dark".

..Peeved.

This is very much the kind of thing I meant when I suggested above somewhere that PBR is going require interventions of some sort for nearly everyone active in SL, and not just creators. PBR renders brights brighter, and darks darker, and in particular some interiors are now going to be gloomier.

In this case, it's not after all a big deal: people are going to need to learn to set out interior lighting in some builds (depending upon the build, and the default EEP), or set up reflection probes to moderate the lighting. Or of course, visitors and explorers can start carrying flashlights, which sounds almost fun!

But, again, the idea that this is going to roll out and the only thing most people will notice is "WOW NEW SHINY!" is a fallacy.

[Qie Niangao]

I haven't checked any commercial PBR pre-fabs that use reflection probes, but I'm thinking they'll need to come with a HUD or something to make more user friendly scripted control via https://wiki.secondlife.com/wiki/LlSetPrimitiveParams#PRIM_REFLECTION_PROBE —unless we think everyone will just learn to mod their own reflection probes in the build tool, which would seem to expect a lot.

[Scylla Rhiadra]

38 minutes ago, Qie Niangao said:

I haven't checked any commercial PBR pre-fabs that use reflection probes, but I'm thinking they'll need to come with a HUD or something to make more user friendly scripted control via https://wiki.secondlife.com/wiki/LlSetPrimitiveParams#PRIM_REFLECTION_PROBE —unless we think everyone will just learn to mod their own reflection probes in the build tool, which would seem to expect a lot.

Yes!!!!!

[Love Zhaoying]

1 hour ago, Scylla Rhiadra said:

This is very much the kind of thing I meant when I suggested above somewhere that PBR is going require interventions of some sort for nearly everyone active in SL, and not just creators. PBR renders brights brighter, and darks darker, and in particular some interiors are now going to be gloomier.

In this case, it's not after all a big deal: people are going to need to learn to set out interior lighting in some builds (depending upon the build, and the default EEP), or set up reflection probes to moderate the lighting. Or of course, visitors and explorers can start carrying flashlights, which sounds almost fun!

But, again, the idea that this is going to roll out and the only thing most people will notice is "WOW NEW SHINY!" is a fallacy.

I think the point I failed to articulate clearly was, someone had mentioned the possibility of things being "dark" and..I had no clue that meant it could happen to me, with "default" lighting!

[Scylla Rhiadra]

1 minute ago, Love Zhaoying said:

I think the point I failed to articulate clearly was, someone had mentioned the possibility of things being "dark" and..I had no clue that meant it could happen to me, with "default" lighting!

Yes because PBR viewers also change, to greater or lesser degrees, legacy materials and, most importantly, the rendering of light generally. Which is why it's "broken" some old EEP settings (and why LL had to create a new "Midday" default EEP).

[Zalificent Corvinus]

1 hour ago, Scylla Rhiadra said:

Or of course, visitors and explorers can start carrying flashlights, which sounds almost fun!

And so, thanks to the "miracle" of PBR, we say "Welcome back" to nuclear powered 10m radius face lights!

 

[Scylla Rhiadra]

1 minute ago, Zalificent Corvinus said:

And so, thanks to the "miracle" of PBR, we say "Welcome back" to nuclear powered 10m radius face lights!

 

I PREDICTED THIS WEEKS AGO!!!!

Just sayin'!

[Love Zhaoying]

Just now, Scylla Rhiadra said:

I PREDICTED THIS WEEKS AGO!!!!

Just sayin'!

Hey, we can all be like one of the Saints, always depicted with a big bright halo.

[Zalificent Corvinus]

 

5 minutes ago, Love Zhaoying said:

Hey, we can all be like one of the Saints, always depicted with a big bright halo.

I don't need no stinking halo!

 

Edited January 18 by Zalificent Corvinus

[Love Zhaoying]

1 hour ago, Zalificent Corvinus said:

 

I don't need no stinking halo!

 

Oh, so those montrals can give one "evil" powers too? And here, I thought they were just for sensing movement. (Because that's what Google said.)

Are you SURE you need extra evil powers?

[UnilWay SpiritWeaver]

Is this now our everything PBR thread for non-experts thread or is there a better one somewhere?

I grabbed the Firestorm PBR alpha today so just starting to explore this.

I notice colors 'pop' more - brighter brights, darker darks, but not muted darks. It looks really good on my avatar skin.

I think my heavy use of lights in my SL home will pay off, as they have more noted impact.

I seem to have higher FPS, but my fans want to spin up. I'm on an AMD 2700 with an nVidia 2080 and 32gb of ram, circa 2019 PC.

I have NOT yet tried to apply any PBR textures to anything like the first post of the thread noted. Just starting my journey with PBR. I don't see anything in the library labeled 'PBR' so I have yet to even figure out how to recreate the issue.

Edited January 19 by UnilWay SpiritWeaver

[Love Zhaoying]

1 hour ago, UnilWay SpiritWeaver said:

Is this now our everything PBR thread for non-experts thread or is there a better one somewhere?

I grabbed the Firestorm PBR alpha today so just starting to explore this.

I notice colors 'pop' more - brighter brights, darker darks, but not muted darks. It looks really good on my avatar skin.

I think my heavy use of lights in my SL home will pay off, as they have more noted impact.

I seem to have higher FPS, but my fans want to spin up. I'm on an AMD 2700 with an nVidia 2080 and 32gb of ram, circa 2019 PC.

I have NOT yet tried to apply any PBR textures to anything like the first post of the thread noted. Just starting my journey with PBR. I don't see anything in the library labeled 'PBR' so I have yet to even figure out how to recreate the issue.

There are unfortunately, a lot of PBR threads.

My own thread (I need to visit more often):

 

[arton Rotaru]

On 1/18/2024 at 5:09 PM, Love Zhaoying said:

Not sure which PBR thread this belongs in, so putting it here:

Yesterday I finally saw a situation where, if I rez a legacy build, it is almost completely dark inside (at certain shared environment times) with my current graphics settings under PBR.

D'oh!

This is a Peeve (and probably belongs in the Peeve thread) because, anyone visiting, or even I, must override the default settings so they aren't sitting in the dark.

I think that I missed this because, when testing PBR in my "cavern", I had some reflection probes setup that made it "not dark".

..Peeved.

Sure what you are seeing isn't just because of that you may have shadows enabled?

[Love Zhaoying]

5 minutes ago, arton Rotaru said:

Sure what you are seeing isn't just because of that you may have shadows enabled?

Possibly, I'll give a try to turning off shadows.

Noting that, nothing is above me (except possibly "clouds"). 

It didn't occur to me that being "inside" would cause an effect that  "everything is in shadows"...

[Qie Niangao]

Above I threatened to create a UI for the scripted function that can adjust a reflection probe's ambiance (with PRIM_REFLECTION_PROBE attributes), so I took a shot at a design. This concoction made me realize just how much I didn't know, which means this is sure to include errors, so it's a DRAFT strawman very much in need of review:

So the basic idea is to illustrate what's behind a single¹ floating point number, "ambiance", that can be set about a creator-supplied reflection probe.²

As I understand https://wiki.secondlife.com/wiki/PBR_Materials#Fine-Tuning_Reflection_Sample_Volumes, reflection probe ambiance has three ranges:

•  0 - 1 adjusts the share of the resulting ambient light that's due to irradiance (indirect lighting³) rather than the environmental ambience from EEP settings,
• 1 - 4 further boosts the irradiance level from both local and sky lighting, and
• 4 - 100 boosts exclusively the sky-lit component of irradiance

which is what the little graphic is supposed to show to help the user understand what's driving the effect they're controlling. The way to set the value might be simply touching anywhere from left to right on most of the HUD, with the number in the box updated accordingly, and/or touch the box itself to invoke a standard script textbox to enter a precise number.

The script would also use llGetEnvironment to find some current EEP settings at the position of the reflection probe. These include two colors:

• SKY_AMBIENT (which I think corresponds to the wiki's "Environment Ambient" that I'm calling "EEP ambience" here) and
• the total_ambient attribute of SKY_LIGHT (which I'm calling "extra sky" in hopes it's the color of the wiki's "only indirect lighting received from the sky")

as well as SKY_REFLECTION_PROBE_AMBIANCE which appears to impose a minimum setting between 0 and 10. I think this means that if a user tries to set it lower, it will peg at this minimum while the probe is in this EEP environment. The UI tries to show that in order to reduce possible confusion when a setting doesn't seem to take effect. Note that it should be possible to set it below the minimum (as in the example) because the probe may end up being used in a different environment.

Again, I'd love to get feedback on all this before I run (further) amok.

____________________________
¹ Technically, a script can also:

• toggle the whole reflection probe on and off
• set a donut hole "clipping distance"
• set it sphere or box, and
• toggle whether avatars are reflected.

Those are simple controls that could be added to the HUD or just basic script dialog and textbox interactions, but I'm kinda wondering if they add value: would creators really want their end-users changing those by script rather than in the build tool interface? I don't have a strong intuition about that.

² If a product includes multiple reflection probes in the linkset with potentially different settings for each, there's also need to be a way of navigating among them (at least by name).

³ Yeah, "indirect irradiance" is redundant but it might be some hint about what light is involved. If there are better, easier labels for these categories, they'd certainly be welcome.

[Love Zhaoying]

1 hour ago, Love Zhaoying said:

1 hour ago, arton Rotaru said:

Sure what you are seeing isn't just because of that you may have shadows enabled?

Possibly, I'll give a try to turning off shadows.

Noting that, nothing is above me (except possibly "clouds"). 

It didn't occur to me that being "inside" would cause an effect that  "everything is in shadows"...

@arton Rotaru, yep! Turning off shadows "fixed" it.

Were things this "bad" (dark) before PBR? I had shadows off back then.

[UnilWay SpiritWeaver]

23 minutes ago, Love Zhaoying said:

@ arton, yep! Turning off shadows "fixed" it.

Were things this "bad" (dark) before PBR? I had shadows off back then.

No and that seems weird to me. I got the firestorm PBR viewer yesterday and have been going all over the place with shadows on and haven't seen this issue as of yet. I've had shadows always on for a few years now. Long enough that I forget when and what SL looked like before I flipped it on.

 

Same lighting, inside a 3x3x3 hollow prim with prims above and below so there's no gaps:

 

Without PBR (Firestorm release viewer) I see nothing:

With PBR (Firestorm PBR Alpha) I get myself as a shadow:

What the scene looks like in PBR (Firestorm PBR Alpha) using region lighting:

 

So I don't get black walls in the dark, just no scene.

Outside of the box, with or without shadows it looks like this:

Edited January 19 by UnilWay SpiritWeaver

[Love Zhaoying]

50 minutes ago, UnilWay SpiritWeaver said:

No and that seems weird to me. I got the firestorm PBR viewer yesterday and have been going all over the place with shadows on and haven't seen this issue as of yet. I've had shadows always on for a few years now. Long enough that I forget when and what SL looked like before I flipped it on.

Like, now I understand better a few posts I saw about how people may need to set out lights..

A real shame, too bad they couldn't figure out how to have shadows without make "inside buildings" dark!

..because none of these old Prim builds I have used lights! (None so far, I wasn't going to test them all and find out but it's not that hard to do.)

 

[Jenna Huntsman]

8 minutes ago, Qie Niangao said:

Above I threatened to create a UI for the scripted function that can adjust a reflection probe's ambiance (with PRIM_REFLECTION_PROBE attributes), so I took a shot at a design. This concoction made me realize just how much I didn't know, which means this is sure to include errors, so it's a DRAFT strawman very much in need of review:

 

Some feedback:

• "EEP" ambiance isn't a constant value as this changes with the sky setting, so there should be a swatch showing the ambient setting.
• Any probe ambiance value above 1 is a multiplier on the irradiance contribution - values above 4 make for extra sky contribution (so, "extra sky" should be clarified)

  3 hours ago, Qie Niangao said:

  he total_ambient attribute of SKY_LIGHT (which I'm calling "extra sky" in hopes it's the color of the wiki's "only indirect lighting received from the sky")

   

• My own testing of that function has told me that fade_color is usually a more accurate approximation of indirect light produced by the environment preset. (It does require being clamped into a valid range, however).

[Arduenn Schwartzman]

11 hours ago, Qie Niangao said:

Much respect for the way Qie visualized what the ambient float value does. And I'm sure it's not easy to translate a large set of parameters that define a complex 3D world of interacting objects, materials, light sources, environments and reflection probes into a control panel that dumb users like me can use. But to me, as a dumb user, even this single float value confuses me a lot and makes me wonder and fear what the next step in the evolution of virtual world settings is.:

Edited January 20 by Arduenn Schwartzman

[elleevelyn]

On 1/19/2024 at 3:35 PM, UnilWay SpiritWeaver said:

 I don't see anything in the library labeled 'PBR'

in Linden Viewer 7.1.2 look in folder Library \ Textures \ Materials

[Qie Niangao]

44 minutes ago, Arduenn Schwartzman said:

even this single float value confuses me a lot

Me too! And now any way I draw it, it ends up looking like we're entering supercritical phase in 3, 2, 1, …

It all makes me appreciate my lack of preparedness for doing stuff in SL now. There must be some theoretical underpinnings for why these several light sources should all combine into this one floating point number in just this way, but I don't even know how to ask the question coherently, and surely couldn't understand the "answer"—which I'm now realizing would be more a syllabus than a paragraph.

It may have started when I didn't pay proper, disciplined attention to EEP. I just turned the dials and watched until I got a pretty picture, vaguely aware that there might be other settings with the "same" result but not appreciating that every path through the maze led to different points that would become starkly distinct when PBR materials entered the scene.

This may be why EEP settings are causing such angst for others, too, delving into PBR now. Those pretty Environments? Behold what their specific settings actually meant!

8 hours ago, Jenna Huntsman said:

My own testing of that function has told me that fade_color is usually a more accurate approximation of indirect light produced by the environment preset. (It does require being clamped into a valid range, however).

First, a huge thank you for looking at this and giving feedback; I was so hoping you specifically would take a look. Now I'm thinking I too will end up doing some "empirical study" to better inform my next pass at this.

It seems, if I'm reading your other notes correctly, that my laziness got me in trouble: I was trying to avoid putting labels inside swatches that would change colors depending on the environment in which the probe was being set. As a result, I put the labels outside those swatches along a horizontal line, so they erroneously appear label the level of that line, not the swatch above or below it as intended. It was all to avoid finding a contrasting and readable label color at runtime but now I think simple black or white will work for inside-swatch labels depending on the value of the swatch color.

The "EEP ambiance" label text doesn't appear to work anyway, and I guess "Environment Ambient" needs to squeeze in there somehow.

There's also a nagging problem with the very horizontality of that 0-1 range sum of Environmental Ambient and indirect "Irradiance" lighting. I need to show that there's a simple proportional amount of each, but that suggests there's a y-value that's constant over that range and there's not. I stared at that for a long time and just couldn't find a practical, less confusing alternative. (This is related to why I find the single float so confusing: it doesn't monotonically adjust any perceptible quantity except over piecemeal ranges, and even there it's a non-obvious assortment of quantities being adjusted. Well, non-obvious to me, that is.)

[Jenna Huntsman]

14 hours ago, Qie Niangao said:

First, a huge thank you for looking at this and giving feedback; I was so hoping you specifically would take a look. Now I'm thinking I too will end up doing some "empirical study" to better inform my next pass at this.

It seems, if I'm reading your other notes correctly, that my laziness got me in trouble: I was trying to avoid putting labels inside swatches that would change colors depending on the environment in which the probe was being set. As a result, I put the labels outside those swatches along a horizontal line, so they erroneously appear label the level of that line, not the swatch above or below it as intended. It was all to avoid finding a contrasting and readable label color at runtime but now I think simple black or white will work for inside-swatch labels depending on the value of the swatch color.

The "EEP ambiance" label text doesn't appear to work anyway, and I guess "Environment Ambient" needs to squeeze in there somehow.

There's also a nagging problem with the very horizontality of that 0-1 range sum of Environmental Ambient and indirect "Irradiance" lighting. I need to show that there's a simple proportional amount of each, but that suggests there's a y-value that's constant over that range and there's not. I stared at that for a long time and just couldn't find a practical, less confusing alternative. (This is related to why I find the single float so confusing: it doesn't monotonically adjust any perceptible quantity except over piecemeal ranges, and even there it's a non-obvious assortment of quantities being adjusted. Well, non-obvious to me, that is.)

I did some additional testing just now, here's what I found:

total_ambient is a combination of all things that contribute to ambient lighting directly, so that means:

• EEP Ambient Color
• Cloud color (likely multiplied by cloud coverage value)

That means, that with newer PBR presets that total_ambient may read ZERO_VECTOR, if their EEP ambient color is set to black ( <0,0,0> ) and have the cloud coverage set to zero, although their actual observed ambient light value is something else - hence why I say that fade_color with an additional clamping mechanism is a better measurement (among other reasons).

 

Anyway - Some feedback on the graph you made, just from personal opinion, and I'm not sure I have any good solutions for these (As I write, I've had a few drinks and can't think straight enough haha!)

• The graph suffers from non-linear range issues, meaning you have the 0-1 scale, the 1 - 4 scale and the 4 - 100 scale represented by the same distance
• Not sure what the "Current EEP minimum" slider is meant to do. Could be that my inebriation is inhibiting me from understanding, but clarification would be appreciated.

On 1/19/2024 at 9:12 PM, Qie Niangao said:

² If a product includes multiple reflection probes in the linkset with potentially different settings for each, there's also need to be a way of navigating among them (at least by name).

The way that I've handled this up until this point is to put the name of the room that the reflection probe is in to the description box, which can then be read later by a script. Generally you want all reflection probes in the same room to share the same ambiance value.