Rippled Paint Mirage Effect?

Good evening all,

Please forgive me if this topic was brought up before. If one knows me well, then one knows I'm always trying to be innovative, and use problems to my advantage. Apparently, TANE has some normal map problems. I see that a screenshot by Zec shows how the dome has a wavy reflection to it. That being said, can we apply this to locomotive sides?

When fresh paint is applied to a metal exterior, sometimes, the gloss and reflectivity isn't smooth. As a matter-of-fact, it's never smooth.

You can see how the sides of locomotives appear ripple and elegant, with visible indentations of the body. I think that this effect can now be achieved with proper/improper implementations of different bump materials.

I like to think that I am getting close to this effect with m.tbumpenv- look at the roof of the 66, which I'm currently reworking:

Screenshot 2015-05-25 06.12.28 by rumour3, on Flickr

The bumps respond to reflections and lighting changes. I could probably make the paint a little shinier, but you get the idea.

I make my normal maps from a hand-drawn greyscale image. The bumps are produced from airbrushing patches of darker and lighter grey onto the base mid-grey, and then running a normal map filter on it. I use the Nvidia Photoshop one, in Photoshop Elements).

R3

That would be about it. As for the reflections, it definitely would be just that if you make the lighter areas more reflective, darker ones less, etc... However, it would also be taking advantage of a triangle error if the certain blotches (maybe the lighter ones) could be ever-so-slightly distorted/translated so that it appears more wavy than uniform. However, I don't think materials like this exist, nor if N3V are capable of developing such a feature.

EDIT: I realize that assigning an environment-reflective material to a whole locomotive will give that glossy look. But, will this allow for super-glossy surfaces on engines, almost as intense as the water in T:ANE?

EverTrainz said:

I realize that assigning an environment-reflective material to a whole locomotive will give that glossy look. But, will this allow for super-glossy surfaces on engines, almost as intense as the water in T:ANE?

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The simple answer is yes. With m.tbumpenv you can get anything from a flat, matt appearance to a full environment reflection. This means that you can have areas of matt dirt on otherwise gloss paint, all within the same material. The key is to pay attention to the alpha channels of both the diffuse and normal images. The alpha of the diffuse controls the overall glossiness, and the alpha of the normal controls the strength of the specular effect.

A common problem that crops up when people first use m.tbumpenv is to either not reference, or not provide, an alpha channel to the diffuse .tga file. This gives a totally reflective material, similar to chrome.

Regards

R3

rumour3 said:

The simple answer is yes. With m.tbumpenv you can get anything from a flat, matt appearance to a full environment reflection. This means that you can have areas of matt dirt on otherwise gloss paint, all within the same material. The key is to pay attention to the alpha channels of both the diffuse and normal images. The alpha of the diffuse controls the overall glossiness, and the alpha of the normal controls the strength of the specular effect.

A common problem that crops up when people first use m.tbumpenv is to either not reference, or not provide, an alpha channel to the diffuse .tga file. This gives a totally reflective material, similar to chrome.

Regards

R3

Click to expand...

I'm a no-go at setting up materials and textures, so I'll need to peer into the Wiki for more help on setting up normal maps and textures. However, in Trainz context, does glossiness mean the reflectivity, and specular strength mean the amount/distance reflected of the environment? This is all fresh information for me, thank you for the help.

With the new 'tbumpenv' cubemap in TANE (has a 'scenery' segment, as well as a sky semi-overcast sky) you could quite possibly achieve this with an appropriate normals map, and specular and env maps, to produce the rippled panels.

I successfully produced something that looked like patterns polished into the side of a steam loco some time back, as a test.

Regards
Zec

So, until I upgrade to TANE, will the TS12- env. reflections only cast sky reflections? I was thinking, since water is reflective of all objects, the material (used by latter) is definitely there, it just needed to be discovered and set up properly.

rumour3 said:

... The alpha of the diffuse controls the overall glossiness, ...
R3

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Absolutely. I fell into the trap of using a plain dark grey colour for the entire alpha channel of my locos. Looked OK in TS12 but a bit silly in T:ANE with semi gloss soot! When I find some time I need to work out a way of remaking those alpha channels without hand painting every mapped face. I'm thinking of starting with a grey scale copy of the diffuse texture and progressively darkening it.

I like the ideas expressed in R3's post (#2).

Paul

My approach is to map the faces of the model into broad areas on the texture based on shininess. This means that, for example, all the underframe components will sit within an area painted pure black in the alpha channel. The painted surfaces will sit within an area that starts as a dark grey, whilst shiny metal such as buffer shanks and wheel treads will have a lighter grey. I also keep the AO bake as a separate layer, and overlay this onto the alpha layer to ensure that the shadow areas aren't shiny. It's quite handy to keep the alpha channel as a layer in the same working image file as the diffuse, and to treat each piece of weathering as a new layer. This allows you to add bits to the alpha channel based on the layers within the main diffuse image, so an area of soot could be made matt by copying the object, darkening to black and then merging into the alpha channel layer (or keeping as a separate object so you can delete it if necessary). It requires a bit of care to manage the image file layers but it makes it a lot easier to get subtle effects consistent between the diffuse and alpha images. I produce the final output by turning layers off and on as appropriate, and copying the alpha channel greyscale into the mask.

My image editor of choice for anything involving an alpha channel is an old version of Corel PhotoPaint, which allows alpha channels to be created with a simple 'paint on mask' option. I've not found anything to touch it for simplicity, but it won't run on Windows 7 or 8 and so I use a Windows 2000 VM for most of my image editing. I only tend to use Photoshop Elements for the normal map creation.

R3

Thank you. That was very interesting and I've copied the post so I can try that when next I'm in that space.

My preferred image editor is Corel's PaintShop Pro but its support for manipulation of alpha channels is abysmal.

Cheers

Hi All
You can achieve quite a bit with the 'env' map, and a specular map for that matter.

For a basic start, I make an env map with different shades of grey for specific parts. Polished brass/metal gets light shades, paintwork gets mid shades, and blacks or frames or similar get relatively dark.

Onto this, I then add the weathering (either brighter or darker than the base colours, depending on what is being seen!). Then, to finish it, I add the AO bake. That way areas in AO shadow are going to have less reflection (especially good at night!).

Now, this is for creating an env map 'from scratch' over a blank texture. However, you can actually get around this if you've worked in layers for your main texture. What I do (in addition to the above 'baselines') is that I take the main texture, and change the colours (flood fill normally) of the base 'colour' layer. Then I work through the layers of rivets, etc, changing the colour to match the base layer; and adjusting any blending options (e.g. embossing, drop shadows, that sort of thing) for the objects. I generally leave drop shadows, to create a bit of 'depth' around rivets/etc. Then play with either a colour overlay, or brightness/contrast adjustment, of the weathering layers to create the weathering in the env map.

Once you get the hang of it, it's not hard to make a basic, but detailed, env map. The same for a specular map actually. I've seen a few things that give me ideas for future as well. For example, ripples in panels would really work well when done with both the specular and normals maps.

At a minimum, definitely try to include the AO bake and weathering in the env and specular maps to help break up the effects (as they would in reality)

Regards

Zec,
By "env map" are you referring to the diffuse alpha channel? I cannot recall it being called that before. AO and weathering layers, or even rust layers, are well understood.

Hi Paul
You're correct there As I work with a full 'layered' psd for it, it remains a separate image until I've got it finished (I even work with separate tga's for diffuse and alpha, and normals/specular during development so I can easily/quickly update one or the other).

Regards

Glossiness seems to be different from the actual reflection, though. There was a picture of one of Ocemy's locomotives with reflections of hills and trees, but I don't want to scour the forums for it. Anyway, said reflections were black-ish due to the sun's position, but these are pretty much what I'm hoping for. These reflections of actual objects are what make the glossy, ripple sides look, well, glossy. Does the Ocemy steam locomotive have m.tbumpenv materials? It has a type of reflection I'm looking for.

EverTrainz said:

Glossiness seems to be different from the actual reflection, though. There was a picture of one of Ocemy's locomotives with reflections of hills and trees, but I don't want to scour the forums for it.

Click to expand...

Perhaps it was this one. While I like the reflections, those on the cylinders and piston housing seem unrealistic to me. There also appears to be reflections on the driving gear that I never noticed before.

Anyway, said reflections were black-ish due to the sun's position, but these are pretty much what I'm hoping for. These reflections of actual objects are what make the glossy, ripple sides look, well, glossy. Does the Ocemy steam locomotive have m.tbumpenv materials? It has a type of reflection I'm looking for.

Click to expand...

There is this picture I took of Calbourne of the Isle of Wight Railway in 2010.




The sun is coming from the right side and you can see reflections of people in the water tank paintwork. But there are slight distortions as you might expect in a large flat surface. There are also dents and bumps in the cylinder and dome.

Thinner metal was used on the diesels, so I suppose such indentations would be more evident. How could I achieve the reflections with indentations on the body, like Calbourne?These would only be useful on clean variants of locomotives, as dirtier models' gloss would be dulled by grime and soot.

Hi EverTrainz
Those would be quite easy to achieve in the normals map. If generating a normals map from a greyscale 'bump' map, you'd create an appropriate dark or bright spot there in the shape of the dint/indentation/whateverithappenstobe Or, for rippled surfaces, you'd slightly distort it with a similar effect (but fairly slight and over a larger surface).

Regards

Thanks Zec. Rumour's bump maps also do this. However, will the slight distortions also apply to the env cubemap?

They do in T:ANE, not sure about TS12 though (I've not actually tried it on highly reflective surfaces). I noticed it when playing with a 'test' object the other day lol

Zec

Cool, I'll try in TS12 when I return home.