scottb613

PBR Lighting - affect on models and textures ?

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Hi Folks,

So with the news of P3Dv4 PBR lighting imminent - what has to be done to models and textures to take full advantage of this ? Are there new texture sheets that need to be made to capitalize off this - or will everything just look better by default ? I've seen advertisements for XP where they specifically advertise PBR materials - is this just advertising hype - or is work really required ?

Thanks...

Regards,
Scott

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If the textures don't include PBR they won't look better.

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5 minutes ago, JoeFackel said:

If the textures don't include PBR they won't look better.

Hi Joe,

Thanks - but what needs to be done - is this something an end user can do via textures - or are changes to the model needed as well - would model changes be available to the end user via something like Arno's MCX ??? LOL - I have lots of questions... I kind of know my way around both models and textures - just no clue on the PBR thing...

Regards,

Scott

Edited by scottb613

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Nothing will work better automatically, textures must be remade, and the object must be recompiled with the new SDK.

Recompiling is not a big deal (for the original developer with the source files), but textures requires more work, depending how they were made.

If a developer made all its textures by hand, using any traditional painting program (like Photoshop, Gimp, etc.), they are not easy to convert to PBR. There are some utilities that can help doing that, but they still require some manual work, if only to indicate which parts of the texture are supposed to be metallic. But they won't ever look as good as if the texture was designed to be PBR from the start, using PBR-aware painting tools like Substance, Quixel, 3DCoat, etc. which use pre-made libraries of PBR materials, which are calibrated to conform to Physically-Based Rendering (PBR), and require proper normal maps to obtain the full effect.

Some developers already use such tools, and they had to dumb down the exported textures to support the current P3D version or FSX. Those that saw were the market was going (including those that were already accustomed to PBR, because of X-Plane...), might have an easier time and some headstart.

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Hi Umberto,

Thanks so much for the details - seems like it may be a while before many of the developers are on board... While I've been using PSP,PS, and Gimp for decades - I've never heard of the others - I'll poke around even though it won't help if I don't have the source files... Appreciate you taking the time...

Regards,
Scott

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5 hours ago, virtuali said:

Nothing will work better automatically, textures must be remade, and the object must be recompiled with the new SDK.

Recompiling is not a big deal (for the original developer with the source files), but textures requires more work, depending how they were made.

If a developer made all its textures by hand, using any traditional painting program (like Photoshop, Gimp, etc.), they are not easy to convert to PBR. There are some utilities that can help doing that, but they still require some manual work, if only to indicate which parts of the texture are supposed to be metallic. But they won't ever look as good as if the texture was designed to be PBR from the start, using PBR-aware painting tools like Substance, Quixel, 3DCoat, etc. which use pre-made libraries of PBR materials, which are calibrated to conform to Physically-Based Rendering (PBR), and require proper normal maps to obtain the full effect.

Some developers already use such tools, and they had to dumb down the exported textures to support the current P3D version or FSX. Those that saw were the market was going (including those that were already accustomed to PBR, because of X-Plane...), might have an easier time and some headstart.

Are any of PBR-aware tools that are freeware by chance? I haven't actually started texturing many of my buildings for my own airport project, so if these tools are free or inexpensive, it'd probably be a good idea to start on the right footing, so to speak...

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3 hours ago, Benjamin J said:

Are any of PBR-aware tools that are freeware by chance? I haven't actually started texturing many of my buildings for my own airport project, so if these tools are free or inexpensive, it'd probably be a good idea to start on the right footing, so to speak...

If you want to create new PBR materials from scratch, I think Blender has the ability to paint in 3D, and specify PBR properties for materials. Never used it, just saw a couple of tutorials on Youtube about it.

If you have existing textures you would like to convert to PBR, there's a free tool which has been just released, called Materialize, which seems nice:

 

Don't expect the same results of a material made with properly calibrated PBR material libraries, like those included with Substance or Quixel.

These are made by taking multiple pictures of the material from different angles, to record how it reacts to different light angles, and to extract the pure color with no shadows (the Albedo), which is one of the trickiest parts which usually cause most of the trouble when trying to convert an existing Diffuse texture (which doesn't contain *any* shadows), to an Albedo texture, which is the pure color with no lighting information in.

Edited by virtuali
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Thanks Umberto! A wonderful starting point for me to start messing with this. I do all my modeling in Blender so I'll have a look at what you mentioned, though from what I understand the 'paint in 3D' function is not very intuitive. iv'e never tried it myself though. Materialize looks cool - I'll have a close look at that!

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i did not make textures setup for PBR. And have no plans to convert them. This will be good for a fresh project. Also PBR may take more FPS away and we need as much as we can with a panel like this.

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For photoshop users 😉

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Awesome! Can this be downloaded yet? It seems like it's still an alpha version?

It's great to see the wealth of resources becoming available though, will make everything so much easier! I reckon the Blender-P3D plugin will have to be updated to allow for the application of the relevant texture layers though.

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6 minutes ago, Benjamin J said:

Awesome! Can this be downloaded yet? It seems like it's still an alpha version?

It's great to see the wealth of resources becoming available though, will make everything so much easier! I reckon the Blender-P3D plugin will have to be updated to allow for the application of the relevant texture layers though.

Visit youtube and below the video are the links 😉

Edited by awf

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On 11/27/2018 at 6:45 AM, scottb613 said:

seems like it may be a while before many of the developers are on board...

Not if the market starts demanding it. If the community stops buying add-ons just for the sake of having an airport to fly into and demand quality instead, things would change rather quickly. I am very picky who I spend my money with, even when there are holiday sales etc. Get with the times and deliver the goods worth my money. 🙂 

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Wonderful, thanks Andre! This will definitely help. I've had a look at the licensing options for things like Substance as well, and have to say I was surprised it was as 'cheap' as it is. Still too expensive for an amateur like me, but also not way out of my league. perhaps, if I have a more long-term goal with scenery design, I may consider acquiring a license. I'd just have to understand first which part of Substance will benefit me most, as it appears to be a program of modular design. Umberto, I'm assuming here you use all parts of it?

Watching the Youtube video it's quite clear to me that I don't have much of an understanding yet of how PBR textures are different from the 'normal' textures we have been using so far, so I'm going to look at some articles that describe the differences. After all, I've only just been wrapping my head around normal/bump maps... Talking about being green 😝 But, what's quite clear to me is that there's a big difference between using PBR-aware textured directly versus taking existing textures and applying PBR-style effects to using a mask - this to Umberto's earlier point. I think I'll have to work out the best workflow, but at least there's already at least two awesome tools available. I'll also have a look to see what options Blender may have, as I suspect they have started to support PBR a while ago already (as Umberto mentioned as well).

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So, to all of you, a question... I've spent some time watching various Youtube videos about how make PBR materials work in Blender, and what strikes me , is that it's actually not that different from what we have been doing before. The difference I see is the existence of one or two new texture maps, and this sort of replaces things like specularity maps... is that correct? Diffuse, alpha and bump maps are not going anywhere and we use them like before. But now we additionally use a metallic and roughness map in addition to easily convey certain properties of the materials. Thus it has become very straightforward to deal with reflection in a way that takes into account basic material properties. In the end, PBR is mostly about interaction of the light with the material. Did I get that right?

I can now sort of see the challenge in making PBR materials if you haven't been doing it from the start... Because all Youtube videos I've been watching simply take a material and apply it as a whole to an object. But, of course, when we model a terminal building, the glass, the metallic frames etc etc all sit on the same diffuse map, which probably complicates the entire process. Instead, if you could just paint the materials onto the model, which is what Substance seems to allow to do, it makes everything a lot easier... Again, did I get that right?

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1 hour ago, Benjamin J said:

I can now sort of see the challenge in making PBR materials if you haven't been doing it from the start... Because all Youtube videos I've been watching simply take a material and apply it as a whole to an object. But, of course, when we model a terminal building, the glass, the metallic frames etc etc all sit on the same diffuse map, which probably complicates the entire process. Instead, if you could just paint the materials onto the model, which is what Substance seems to allow to do, it makes everything a lot easier... Again, did I get that right?

You can also allocate things inside Alpha channels, this will allow you to have texture metal parts, with roughness and other PBR attributes inside the metallic map.

Unity engine allows you to use this technique, were via the Metal texture maps you can use the RGBA channels to define PBR attributes, each games has it owns parameters for example  R=Metal, G=Roughness, B=Empty, A=Occlusion, etc.

Using the Red alpha channel to define metals, black colours will mean is not metal, were white colours means it is metal, and middle colours would mean a level of metal depending of the quantity of white.

But as Umberto pointed out, better results come when you have different textures for different materials as you can set individual parameters achieving better results, having said that, anything converted to PBR will react way better to ambient light using much less computing processing than the old technique.

Regards,
S.

 

 

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Autogen looks so dull... maybe PBR textures will mean shiny windows (and other metallic/glass surfaces)?

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Thanks for the additional answers all! Some very helpful resources shared here. Definitely have a better understanding of PBR now, but I have one more point that confuses me. It's all about the application of those materials onto the models

So, up until now, we would generally map a model with textures made from photographs or that are hand-drawn, typically combined onto larger texture sheets. Of course these are not PBR materials, as they do not include any of the required maps to make it so. Like others have said, one could make these maps on the basis of the diffuse map (and that's what Materialize as well as Materialing Alpha, I think, both do), but it wont look as good as when you use actual PBR materials, made with the express purpose of PBR.

And that's where I get confused. My question, specifically: How does one map PBR-aware materials onto models, on the basis of photographs taken from a site? Given that these appear to be mutually exclusive...

To go with an example: say we model a window with a metallic frame next to a wooden door. What's the best way to map the textures, and retain the different material properties? Do we:

  1. map as before, unwrapping the model to a single diffuse map, on which we combine PBR-aware materials (diffuse maps edited to represent the real-world counterpart, by changing color, for exmaple). The different maps (metallic, roughness etc) sport differential greyscale values to make sure that the door appears 100% rough, but the metallic frame does not.
  2. or do we use 3 seamless PBR-aware textures that describe the separate materials? This approach will then not allow for baking of ambient occlusion and such things, as such effects are inherently not seamless.

I'm guessing approach 1 is still the way things are done. I hope the crux of my confusion is coming across and that I'm making some sense here?

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3 hours ago, Benjamin J said:
  1. map as before, unwrapping the model to a single diffuse map, on which we combine PBR-aware materials (diffuse maps edited to represent the real-world counterpart, by changing color, for exmaple). The different maps (metallic, roughness etc) sport differential greyscale values to make sure that the door appears 100% rough, but the metallic frame does not.

I'm guessing approach 1 is still the way things are done. I hope the crux of my confusion is coming across and that I'm making some sense here?

Yes, that's what you normally do, and it's what products like Substance Painter are designed for: to create multiple layers of different PBR materials, which use *masks* to map cover different parts of the object polygonal mesh. It's not so much different than having multiple Photoshop layers, each one with a mask (to create a composite) just that, in PBR, you are not just setting "colors", but also height, normals, metalness, roughness, opacity, emissive, all at the same time.

Approach #2 is still useful, for optimization. For example, if you have a transparent material you use only on a very small part of an aircraft/scenery, it's usually best to separate it and make it a different material and have it assigned it only to those polygons that are supposed to be trasparent, so you are not calling the more expensive shader (the transparent shader is more complex to draw) for the whole object, just because you have a small transparent window.

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Thanks for the helpful explanation Umberto, this helps a lot! If you don't mind, I sent you a PM with some additional questions.

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Double post... Sort of. I've been looking into Substance a lot since the last post. It helps that there are beginner tutorials on YouTube, with some excellent information. It strikes me that the way to go about 'painting' in Substance Painter is really similar to what I've always been doing in Photoshop. Using material layers, you can mix and blend materials of all sorts to get exactly what you need, and then mask parts to make sure that you are not overlapping materials for walls with materials for windows frames and glass. A very powerful and, frankly, intuitive piece of software, me thinks. Finally, Substance painter can then export the 'flattened' texture (to use Photoshop terms) for use in P3D. I gotta say, at 150$ for a perpetual indie license, I'm sort of thinking it may be a worthwhile purchase, given the quality of work I'll be able to get out of it for, hopefully, years to come!

The one thing I now need to wrap my head around is how textures derived from reference photos play into this. I've gotten somewhat accustomed to e.g. copying a texture of an entire door from a reference photo and pasting it into the right position in Photoshop, then tweak it in ways that would make it fit in the texture (adjusting the color, for example) but this approach does not seem to be... available (or desired?) in this 'new' approach to texturing.

Anybody have any insight into this?

 

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On 12/1/2018 at 12:39 AM, Benjamin J said:

The one thing I now need to wrap my head around is how textures derived from reference photos play into this. I've gotten somewhat accustomed to e.g. copying a texture of an entire door from a reference photo and pasting it into the right position in Photoshop, then tweak it in ways that would make it fit in the texture (adjusting the color, for example) but this approach does not seem to be... available (or desired?) in this 'new' approach to texturing.

Reference photos can still plays some part, by sticking to their name, and be used as a reference only. The old practice of sticking a photo on a 3d object it's showing more and more its age in the days of physically-correct rendering, it's really a legacy of the old days, were the graphic engine could only do very limited lighting, so you had to put as much information possible in the texture, to overcome the engine limitation. This was already an issue with FSX, but with PBR (and the availability of PBR painting tools), photos shouldn't be used in the actual texture. Just put them in a window on the side of the monitor, and look at them, to get a feeling of what *material* you should use. That's the only usage for photos I see now. A photo used as a texture is like a broken clock: it shows the correct time only twice a day...

Getting the hang of when using actual modeled geometry, or artificial detail added with normal/height maps is also key to efficient modeling. With "efficient" meaning both things: from a performance point of view, but also to how your time is spent.

And, with all PBR painting tools, the trick is trying to be as procedural as possible, and reduce manual painting as much as possible. Your goal should be doing 90% of the work done with pre-made materials (just learn to tweak their parameters to fit your project) and pre-made procedural generators like wear, scratches, dust, etc. and paint only the finishing touches, like spot corrections, decals, signs. 

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Excellent, thanks for the detailed post Umberto! Then my confusion is resolved.

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