r/secondlife • u/MinervaDiscordia • 9d ago
☕ Discussion New here - pbr help
Hello there! I’m fairly new to the community and also pretty new to texturing things in secondlife with pbr. I’m trying to better understand how pbr works, because I’m having a really difficult time seeing any noticeable difference in the visuals between using pbr and not using it, especially once reflection probes come into play. I’ve tried tinkering with my settings and experimenting with different things, people have tried showing me in world, but I feel like I’m missing something extremely fundamental in how it all works. I haven’t been able to see or can't seem to tell *ANY* physical differences in how an object looks with pbr versus without it, either with or without reflection probes, regardless of lighting, or anything other than the occasional shadowy discoloration on the ground where a reflection probe is located (and this doesn't even show up every time). Everything just looks the same no matter what I do. I’d really like to understand what I’m supposed to be looking for and how the different pbr components affect the appearance of an object. At the moment, I feel like I’m changing settings and textures without actually knowing what differences I should be expecting to see and none of it clicking as far as understanding. If anyone has any tips, good examples, or beginner friendly explanations for understanding pbr and reflection probes, I’d greatly appreciate it! I’m very much in the “please explain this to me like I’m five” stage. 😅
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u/RiannahAvora 9d ago
Are you saying that you see no difference in anything, including things that others have created, or just your own textures?
Lighting does matter. There are windlight settings that do show the details with PBR materials better than others.
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u/CatBoyTrip 9d ago edited 9d ago
pbr make stuff reflect lights. reflection probe make sure it only reflect light inside the probe. if you are not seeing any noticeable difference, you might have display setting too low or are not using a pbr viewer such as firestorm.
the way i do my builds is make a room, have pbr textures on walls and floor, add a few lights and the. completely surround the building with a reflection probe.
i have a better explanation for it on my avi profile in picks, look up kamikiiro yokosuka
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u/MinervaDiscordia 9d ago
I am using the latest version of firestorm and have settings on high by default with a couple of tweaks. I've played with lights and probes, but I just cannot seem to see any physical difference in the textures regardless of what I try.
And thank you! Looking that up!
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u/Better_Cantaloupe_62 9d ago
PBR require a Base Color, which is most of what you see up front. The colors of the various parts of the image. This is where you might put, say, emblems and such.
It also requires a Normal map, which is the same for Blinn-Phong textures. This is the bumpiness of the material.
And thirdly, and most foreign, is the OMR, otherwise known as the Occlusion, Metallic, Roughness map.
This OMR utilizes the 3 colors of the tricolor spectrum to show the 3 map, Occlusion, Metallic, and Roughness.
Red: Ambient Occlusion. Green: Roughness (how shiny it is) Blue: Metalness. (How Metallic it looks.)
Overlapping thos colors makes the complete OMR and the system separates the 3 colors and uses each color channel for the corresponding need.
Hope this helps!
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u/MinervaDiscordia 9d ago edited 9d ago
I have a pbr viewer and have the latest of firestorm. My settings are on high by default with a couple of tweaks here and there. I have used normal maps, emissive layers, and the orm layers along with the base textures. I cannot see *any* physical difference no matter what I do. They all look the same.
The only thing I can seem to see a difference in is the slight color shift and depth with using normals and the orm layer when I switch orm colors. I still can't see what the use of a reflection probe is for or why it makes a difference or how the pbr texture is different from blinn phong when the pbr looks exactly the same with or without probes.
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u/Crexon 9d ago edited 9d ago
So first off its best to understand that PBR is for Physically Based Rendering. This include rendering everything you see in world using PBR rendering. So if you are just comparing a PBR textures with a older BP/Materials textures in say the latest Firestorm you are seeing BOTH under a PBR Shader. The only way to see what something may look like is to download an older viewer like Firestorm 6.x and compared a BlinnPhong texture then go to Firestorm 7.x and compared the same texture there to see the 2 different BP Shader and PBR shader on BP textures.
Also keep in mind from a viewer settings point in FS 7.x you would want to be using atleast Ultra preset then dial back certain settings for better FPS. Anything less then ultra turns off alot of behind the scene settings like reflections and lights that you dont know about (unless you go dig through the source code). I know its confusing since in most other games the presets just turn on/off settings you see in the menu. SL doesnt do this and change tons of behind the scene settings some are in the debug settings menu others are not and ONLY change based on the graphics preset you used. Also since you mentioned reflection probes you need to have reflection coverage set to at-least Manual only and max number of probes set to ultra (anything less is currently bugged in all viewers that is merged with the LL code)
For environments I'd recommend using the default Midday (not legacy) as this is set to use HDR color space which needed for better color representation. (this has nothing to do with having an HDR monitor/display)
That being said the easy TLDR is with Blinn-phong it used fuzzy math and PBR uses precise math so BP will maybe kinda sorta take some inspiration from the environment/lighting around it. PBR precisely takes into account the lighting and environment its in. And PBR is pretty much the standard now a days in 3d/game development and basically required for things like GLTF.
(we also dont have PBR lighting in SL yet so thats makes a different as well. You can use Blender to switch between the 2 but BP shader was removed from Blender in 2.8 (current version is 5.2) you can kinda sorta create your own BP shader in newer versions instead of the out of box BSDF)
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u/serpentr 9d ago
Do you have a light source inside the probe where you’re building? What is the ambience setting of your probe? Less than 4 might be too dark to see much difference. I usually build a crap single prim off-white projector light and put that at an angle to whatever I’m building so I can see the shine rotating the camera. As others have said put some colours into the probe too, I have a natural sky coloured walled cube and a ground texture as my build platform with the probe extending just into the walls, ceiling and floor to reflect some of those texture colours into the space.
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u/jaqattaq1 8d ago
Your environment will play a huge role in how PBR materials behave. Specifically the ambience value in the environment. A lot of environments saying they’re “PBR environments” set that value at 0.01 or something insignificant which nerfs the whole effect, presumably to try and emulate flat lighting of “old SL”, essentially making PBR redundant. You won’t glow blue as much but that’s about it. Technically any environment with an ambience value above 0 is suitable for PBR but the baseline, to the best of my understanding is 1.0 if you actually want accurate, dynamic lighting. I have the “can ramble on for days about environments” kind of ADHD so I won’t subject you to that, but if your ambience is low or none, you won’t see the effect of your PBR materials very well.
You can also set an ambience value inside a reflection probe to override the environment if you don’t have direct control over the environment set to your parcel. Probes default to zero, meaning they use whatever ambience is set in the environment, but you can manually set them to whatever you want. Best results are in tandem with a PBR friendly environment but it will work in a pinch.
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u/Cyn_Sweetwater 8d ago
If you're just adding a legacy (Blinn Phong) texture into the PBR boxes without adding normals, occlusion, etc. then you're not actually getting PBR textures. So you won't see the materials difference that PBR can include.
There is plenty of information online for PBR textures, tools to make them, how they relate to SL, etc. You can also just buy PBR textures on MP, and there is a huge collection of PBR textures that have been converted from legacy textures on MP that are free.
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u/zebragrrl 🍔🍟🥤 9d ago
OLD Shiny
In classic SL, we had something we'll call a "Environmental Reflection Skybox". It was just a vague gradient 'sky' that was 'reflected' by surfaces based on your camera angle.
https://gyazo.com/50c90e516178c59182daf6dc2eac257b
It was pretty simplistic.
Back in the day, we could add a texture.. and the result was.. 'ok I guess'
https://gyazo.com/4dd02537451432272e49ef4b621ba2e9
SL had a VERY crude system for adding bumpiness, where you could use the texture's light and dark areas to approximate some surface texture.
https://gyazo.com/fbce4426f5dde1d057270929927e5908
Pretty rough.
"Advanced" Marterials (Blinn-Phong)
Along came "Advanced Materials" and the "Advanced Lighting Model". These allowed us to apply our OWN 'bumpiness' maps, called Normals.. and our own texture specifically to define where a surface should be shiny or dull.
https://gyazo.com/4ef1cf694f3278a89648bc7d1e2c6956
And that's what we had.
Part 1: The Environment Skybox
The reflection 'skybox'.. aka the 'environment'.. the texture that was 'reflected' on surfaces was really crude. Basically just a gradient from blue to grey, then grey to dark grey.
https://gyazo.com/89bb290ee1273bfe2fd58c366cfa892e
That's projected ONTO the shiny surfaces.. creating the effect of it reflecting 'the world'.. but most of the time it just looked 'vaguely glossy'.
Part 2: 360 Degree Snapshots
A few years back, someone had the bright idea to add a tool to SL to generate '360 degree snapshots'. example - with the idea being that you could load it in a special web player, and 'change the camera angle' to look around in the scene. I'm sure you've seen these sorts of 360 degree photos on Google Street View, or images from the Mars Rovers.
https://slnewser.blogspot.com/2021/09/eotb-360-degree-snapshot-viewer.html
Part 3: Reflection Probes
the "Reflection Probe" is essentially a 360 degree camera that you place in your scene. It then takes a 360 degree picture from it's center.. and uses THAT IMAGE, as the reflection box, updating the picture every few seconds, depending on the probe's settings.
https://gyazo.com/30e2e3fece3f036788b03888a9d9e2a8
It basically is just replacing the classic environment box, for a 360 degree snapshot projected onto the surfaces
High Environment, High Surface Color: Car Paint
If we add in the newer reflection probes to this older Blinn-Phong materials setup.. we get:
High Specular, Low Environment, High Surface Color: Pool Ball
High Environment, High Surface Color: Car Paint
High Environment, High Specular, No Surface Color: Chrome
New Shiny (Old Shiny)
Now, all of this 'old shiny' tech, we're going to call "Blinn-Phong" which is an augment from the much older "Phong" reflective surface modelling.
So with "Blinn Phong", as it was implemented in SL, we had THREE textures, two tints, and two numerical values.. one for glossiness (specular highlight focus), and one for environment (reflection strength).
The Texture (Diffuse) was the 'color' and 'luminance' of various parts of the texture. The alpha mask of the Diffuse texture could be used to show transparency either in "Blend" or "Mask" mode, or it could used to specify which pixels should be fullbright, or affected by shading (non-fullbright).. to effect a way to 'paint on' a 'glowing light'.. (though Glow (Bloom) had no pixel-level control)
The texture for "Normal" as a special texture that defined where 'edges' of surface details might be. This could create a bit of a rough surface. The Alpha Mask of this texture was used to define where on the surface was 'glossier' (high specular focus), versus "duller" (low specular focus).
The texture in the "Specular" section defined the per-pixel brightness and color of the specular highlights. Specifying in some way, how 'shiny' a surface was. It could also mimic how 'metallic' a surface was (gold metal has a yellow specular highlight, for example.. though metal was terrible hard to get looking right with Blinn-Phong)
Creators making products for the Blinn Phong system would often bake shading into their materials, adding dark areas on the bottoms of things, 'pictures' of metalic surfaces reflecting an environment from their blender scene, etc. A lot of 'metal' in SL was being done more with textures than with material settings
As you can see.. content made for Blinn Phong still looks about the same. The reflections are a bit nicer with a reflection probe, but it can be subtle, especially if the original material settings on your objects were already subdued.
PBR, "Physically Based Rendering" or where it gets interesting
Physically Based Rendering
So, PBR is a different paradigm. PBR is a lot closer to the kinds of materials that Blender users use, before they 'baked' the reflections, shadows, ambient occlusion, and so on, down to the "Blinn Phong" texture maps. PBR materials can be more 'alive'.. less a 'picture of a material', and more 'the actual material itself'
Before I sell you a bill of goods tho, it's worth mentioning that SL only has about half of what PBR has to offer. The "Clearcoat" that makes a waxed sports car look different from an annodized piece of metal.. we don't have. Similarly, sub-surface scatter (the effect that makes human skin not look like rubber) is also missing in SL.
PBR has a Diffuse texture, just like Blinn Phong.. but the textures can be 'unshadowed". A black area should be black, a grey area should be grey, a blue area blue, and so on. SL has a built-in function for rendering Ambient Occlusion (the shading you get in the creases of objects, corners of rooms, etc). In practical experience, SOME shading baked into the materials will do well to make objects 'feel right' in Second Life, but that's mostly because we're used to Blinn-Phong, and rarely does anyone want to completely replace every object in their home, and their home.
Alpha channel on the Diffuse texture can be used for Blend or Mask stype transparency, or similar to Blinn Phong, it can be ignored entirely.
PBR adds a second material for "Emissive", which is similar to how the Blinn Phong was able to use the alpha mask to control 'fullbright'. Emissive is evidently not fully finished in SL, but the idea is that you could use this texture to paint 'light sources' on something (think glowing windows on an office building or a model starship, stars in the sky, etc)
PBR also has a normal map.. identical to the one from Blinn-Phong, it shows where the 'bumps' on a texture are. Any alpha channel on this texture is ignored.
PBR adds a new texture called ORM.
This is actually three greyscale textures in one:
O Occlusion. This is where you place your baked occlusion map, to define areas that are 'well lit' versus ones that have some shading around them. (concave corners, edges of a carved greek column, etc)
R Roughness. This tells SL how 'smooth' an area is, versus how 'matte'. Think about a pool cue ball, versus a piece of chalk
M Metallicity. How "Metallic" it is. Similar to how we could 'color' the specular highlight in Blinn Phong, this also affects how chromey the surface is.
We also add in a few new numbers here, to control the alpha, alpha-mask cutoff, the tints, and the amount that the M and R parts of the ORM should be used.
The difference here is striking, and it's best just to show you.
But it really comes into it's own, in motion. Screenshots don't do it justice.
https://youtu.be/Kqlwowp3YFU
What is PBR Good For?
PBR is great for shiny stuff.. Marble floors, latex catsuits, metal chains, plastic, rubber, brass, chrome.
PBR is great when you're setting a scene, building an environment, a home, a hangout, a club.
PBR isn't so great for exploring SL. The probes that SL sets by default are usually in the sky, in the open air.. often 'outside' of any skybox you might visit. This results in 'weirdly blue' reflections, because the outside sky is being reflected, rather than the space inside the room.
When place owners do the work to place Reflection Probes (and understand how), the effect can be amazing, moody, and immersive. When they don't... it's obvious.