Are PBR textures the way to go for new routes

Paulsw2

Ambling on the slow line
I've heard lots about PBR textures (or 'jelly-textures' as some would have it) being terrible if added to routes that already have old-style textures or track splines with traditional ballast texturing. But what about if you're starting a brand new route with no existing texturing. Is PBR the way forward for texturing, particularly if used with PBR textured track?

I've also heard that PBR textures don't really work with TurfFx effects (ie. the grass tends to get buried in the 'jelly') which, if so, would be a bit of a show stopper because TFX is certainly something I want to use in my new routes. What do people think and what sort of experiences have they had with PBR textures? Let us know!

Paul
 
I have been wondering about this also. I think from what I read from the last News Letter that they may have remedied the ground texture issue with the Jelly Fish issues with the new HD S2.0.

I have been updating a few assets from authorized asset creators to the DLS with the PBR effect that makes the texture details stand out fairly good without any weird issues depending on the asset that is done, some of them do not display the PBR effect as good.

By doing a normal map that bumps the textures is touchy to get the desired effect, but when done the little flat details such as scratches in the metals and corners of an asset have the 3D details much better to see. What is very good is that you do not need to have the Shader turned on to ultra to get this effect with the buildings and Train Car assets. The only negative issues of doing this, is the asset file size in MBs goes up from the normal bump, and the alpha map that is needed to create the effect.
I do not see any issues with the Map loading time to take any longer, or any FPS changes, and that is a good, no performance hit from what I can notice.:)
 
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As an experiment I recently updated one of my older routes by replacing ALL its non-PBR textures with their PBR equivalents. The visual difference was so much better that I have now switched over to using only PBR textures in all my new routes.

PBR does have issues that you have to work around. These issues are not caused by Trainz but are inherent in all games, sims and applications that use PBR. Specifically:-

  • PBR and non-PBR textures do not play well together (not a problem if you only use PBR). This includes cases where assets such as track have non-PBR textures for the ballast (problem solved if your track asset also uses PBR or does not have ballast). A growing number of new track asset uploads to the DLS now include PBR textures.
  • You cannot use the "[" or "]" keys with PBR textures to rotate the texture as you paint - each rotation loads in another full copy of the PBR texture and this can lead to performance issues.
  • PBR has problems with sudden large height changes in the terrain - often referred to as the "jelly fish guts effect" (solved by using scenery assets e.g. bushes to hide the "guts"). This has reportedly been solved in the new HD terrain feature.

Some of these can be eliminated or significantly reduced by setting the Trainz Shader Quality to "Standard" or below, instead of its normal "Ultra".


My experiences.
 
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  • You cannot use the "[" or "]" keys with PBR textures to rotate the texture as you paint - each rotation loads in another full copy of the PBR texture and this can lead to performance issues.

So if it not advised to rotate the PBR texture, then how do you avoid the creation of repeating patterns when laying down all but the smallest areas of ground textures - grass for example?
 
Not sure how many PBR textures are seamless but you should remember that most of the repeating patterns aren't as noticeable from the engineer's point of view or if you are at ground level driving a car or walking. If the pattern is overly visible even from ground level either use another texture or hide the obvious pattern with scenery items. Remember you are building your world to be viewed from the ground as if you lived there.

Jack
 
My shader is set as standard and texture detail is set as high. My equipment is a Dell XPS 8940, Win 11 @ 32mb RAM, and RTX 3060 Video card @12GB. I don't have a problem mixing PBR textures with non-pbr textures, nor any problems with track doing strange things, I only use pro track. Also, most PBR textures, at least my assets, are tiled and seamless. You can use the "[" or "]" keys to rotate PBR textures. The problem may be the radius of the texture is set too high, set the radius to a smaller setting.

John
 
Thanks for responses chaps. I think there are two points here: you need to do PBR with PBR. And not rotate the texture (assuming it's seamless). This seems very reasonable.

What about the issue of TurfX? Is it compatible with PBR textures?

Paul
 
And not rotate the texture (assuming it's seamless).

What about the issue of TurfX? Is it compatible with PBR textures?

The advice about not rotating PBR textures came from N3V.

PBR and the Effect Layers (TurfFX, Clutter and Water) are completely independent of each other. They do not interfere or interact with each other. At least I have never encountered any issues.
 
Fyi, HD Terrain (Coming Soon(tm)) avoids the jelly issues with parallax textures by introducing displacement maps (which creates actual geometry rather than faking it).

There is also no performance penalty for rotating textures in HD terrain like there is in the old system (but instead there is a performance overhead for each texture, hence the limit of 16 textures per baseboard).

I should also point out that "PBR" is really the wrong term for the technique used - they are actually "parallax" heightmap textures. I think the name just got used so often it has stuck, but PBR is "Physically-Based Rendering which is more about the lighting rather than the materials used in the ground textures.
 
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My shader is set as standard and texture detail is set as high. My equipment is a Dell XPS 8940, Win 11 @ 32mb RAM, and RTX 3060 Video card @12GB. I don't have a problem mixing PBR textures with non-pbr textures, nor any problems with track doing strange things, I only use pro track. Also, most PBR textures, at least my assets, are tiled and seamless. You can use the "[" or "]" keys to rotate PBR textures. The problem may be the radius of the texture is set too high, set the radius to a smaller setting.

John

If your shaders are set to "standard" then you won't see any of the issues mentioned as the PBR textures seem to behave more like regular versions unles the shaders are set to "ultra". The PBR effect is basically "switched off" with "Standard" shaders. At least in my experience.

That's why I run mine at "standard" as well, so I don't have to worry about compatability with older textures on al the older routes I have and the strange effects that sometimes occur.

I'm looking forward to the new HD terrain if it removes some of those previous problems though.

Cheers,
Piere.
 
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So if it not advised to rotate the PBR texture, then how do you avoid the creation of repeating patterns when laying down all but the smallest areas of ground textures - grass for example?
On my Illawarra NSW route I used rotation while using PBR textures with no ill effects - apparently it increases the file size of the route, but I couldn't see that. The recommended method is to use other textures or scale to break up the repetition.
With the advent of HD terrain and a hard limit on the number of textures used per baseboard, it will be interesting to experiment with textures while attempting to break Trainz and discover HD Terrains limitations
 
If a ground texture has a height map and your settings are on Ultra you should not see a repeating texture issue with most textures. Try it with some of the built-in textures that have height maps. The height map causes the light to react naturally with the humps and bumps. Of course, it the texture has a glaringly obvious feature like a huge boulder then it will stick out no matter what. In Surveyor 2.0, you will also have the color effect layer that can be used to lighten or darken areas of the ground surface to break up patterns.
 
In Surveyor 2.0, you will also have the color effect layer that can be used to lighten or darken areas of the ground surface to break up patterns.

Not in Surveyor 2.0 yet but, I believe, being tested for a future release.
 
Thanks for responses, I'm learning a lot here!

Fyi, HD Terrain (Coming Soon(tm)) avoids the jelly issues with parallax textures by introducing displacement maps (which creates actual geometry rather than faking it).

There is also no performance penalty for rotating textures in HD terrain like there is in the old system (but instead there is a performance overhead for each texture, hence the limit of 16 textures per baseboard).
This is good to hear Tony, though restricting to 16 textures per baseboard is going to be an interesting discipline.

Paul
 
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