Building My First Track - Help/Comments Please

Discussion in 'Track Modding' started by Alan Frost, May 7, 2012.

  1. Tuttle

    Tuttle Technical Art Director - Env Lead Staff Member

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    Well, a lot of stuff here. The learning curve of this kind of things is pretty steep..but I'll try to explain the Real Road using basics as much as possible...:)


    The RealRoad shader is composed by 7 Stages (picture).


    -The Diffuse (Stage 1), on Channel 1, load a basic road texture with a 2:1 ratio (2048x1024). Basically is like a portion of asphalt without grainy details.
    This texture requires an alpha channel (a black/white mask to control transparency and/or other effects by the game engine).
    In this case the alpha channel is used to manage the specularity (default alpha) and wet effect (inverse alpha) and it contains the same details as the diffuse like cracks, surface irregularity, density changes, bumps, patches etc... So this alpha should looks like a "overexposed" version of the diffuse where all the color information being reduced to extreme levels pushing lights on whites and shadows on blacks. It's like a matte used to decide where the color (in our case a special FX) will be applied and where will not (greys are intermediate values=intermediate results)
    So, for the RealRoad, we get stronger wet effects for darkest alpha areas and most dry for whites. At the opposite, we have stronger speculars where the alpha is lighter and less speculars where is darker.

    - The MultiMap (Stage 2), on Channel 2, load a tight tile texture with a 1:1 ratio (512x512 / 1024x1024 / etc etc). This texture should reproduce the tarmac grainy detail...and you can test an almost infinite gamma of grainy, taken by real photos, CGI shaders/maps and/or other generic computer generated image. Usually these maps are for very tight tiling, around 2/5mtx2/5mt (2mtx2mt, 3mtx3mt, 4mtx4mt etc). This means that if your track is 10mt wide you could use 5 (2mt^2x5) repetitions to fill the wide section of your track. You have to pay attention to this aspect as you can gets awfull pattern results using too much repetitions for a specific area..and you should keep the same density for the entire circuit, unless you have different tarmac sections (old asphalt/new asphalt, patches, etc..)

    - The NormalMap/Bump (Stage 3), on Channel 1, load bumps informations for the main section of tarmac (The diffuse map on Stage 1). This map needs more knowledge than others as it's not created by hands. It use all three RGB channels to store normals information...Think at each pixel as a memory cell that store the normal face direction and control how much lighting will receive. It's easy to understand that could be a suicide using real polygons to describe the rough asphalt surface...this is why the game engine use normals maps to fake bumps, cracks, steps etc...
    In our specific case this texture is generated by another texture (is called Bump to Normal), so we do not have so many informations as a real Normal map...but it works pretty fine for a flat surface like the asphalt...and just to describe the bumps charateristics.
    So, this texture is a post-elaboration of the Diffuse map (diffuse map trasformed in a greyscale bumpmap to control light levels then into a Normal Map Filter to produce the final Normal map / see the Nvidia DDS plugin for PS), and needs to be loaded in the same Channel as Diffuse (same Channel=same UV projection, same tiling settings, etc.)
    The blue dominant is caused by the flipped Z coordinate value that is stored in the Blue channel, but I think is not the case to being too techinal...:)

    - The RaceGroove Map (Stage 4), on Channel 3, load a texture with a 2:1 ratio, needful to create the dynamic rubber on the tarmac...and it depends on the track car activity. More the track being used by the car...more you'll get a rubber line. Remember this rubber line will be more and more grippy, so it's not just a visual fx... You can create your own RaceGroove map...or you can just use the ISI one. Due to the fact that this texture contains just almost horizontal/perpendicular elements you've to use the spline mapping to following the racing line, the same as we used to do with the main diffuse map.

    - The SpecularMap (Stage 5), on Channel 2, load a tight tile texture with a 1:1 ratio. This is pretty the same stuff on Stage 2 (the Multimap for details), and works on the same Channel (so the same tiling projection and the same UV). It just adds more details on the specular side...this is why you needs a darkest image to better control the grainy specularity above the tarmac. Same thing on "how to" obtain a texture like this...you can use real photos, CGIs, or the ISI stuff.

    - The MarblesMap (Stage 6), on Channel 2, load a very easy texture - with a 1:1 ratio - wich contains rubber debris (by tires) projected off the racing line. This affect physics as well, as you can loose a bit of grip, driving above those parts of the track. Pretty easy to create...

    - The ReflectionMap (Stage 7), on Channel 3, load whatever you want (this texture is not loaded above your track)...as this Stage is used just to activate the LiveMapper (needed for the wet effect).


    [​IMG]

    And about the shader detail:

    Here you've to learn a lot of stuff...and I suggest you the trial&error, trying to understand how ISIs are working on the Joesville track. You can play with devmode fresnel parameters in real time (before put your values into the shader).

    Sorry mate but you're asking for a HUGE range of informations....so this is a first help...but you've to jump right in...:)


     
    Last edited by a moderator: Jun 30, 2012
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  2. Alan Frost

    Alan Frost Registered

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    Tuttle,

    That is absolutely amazing! Thank you! I will have to read it 100 times for it all to make sense, but that's what I will do.

    And experiment, which I'm already doing...

    Thanks again, fantastic information.
     
  3. Tuttle

    Tuttle Technical Art Director - Env Lead Staff Member

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    Glad to have been of some help Alan...:)
     
  4. Goanna

    Goanna Registered

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    As Alan said, bloody good info Tuttle... [​IMG]

    Cheers

    Goanna
     
  5. Alan Frost

    Alan Frost Registered

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    A simple question.

    Should I be using 'edit mesh' or 'edit poly'?

    I've created road and terrain areas using splines, given them a surface - and then need to convert them into one of the above.

    Many thanks.
     
  6. Alex Sawczuk

    Alex Sawczuk Registered Staff Member

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    poly is more flexible.
     
  7. Alan Frost

    Alan Frost Registered

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    ok, many thanks Alex.
     
  8. ethone

    ethone Registered

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    If you're used to mesh don't worry about it. I've been used to the layout of the tools and context menus of the editable mesh and have yet to switch over to Editable Polys completely. You can do your stuff with either if needs be.

    If you are free to get used to either, pick Poly. :)
    Poly in particular has some selection features that can be useful.
     
  9. Woodee

    Woodee Registered

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    Can you show me visually how these maps fit on a 3dsmax material (non-gmotor material) to import into gJED? Maybe another example for the terrain shader to?
     
  10. lordpantsington

    lordpantsington Registered

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    How they 'fit' is determined by their UVW mapping rather than material. 3 Different Channels, so 3 Different mapping.

    This is a good watch:
    https://youtu.be/foydgOcFstY
     
  11. Gijs van Elderen

    Gijs van Elderen Member

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    For gJED: you need 4 UV Sets, channels or mappings. (Name depends on your moddeling program :))
    and the UV channel order is a bit different.

    But everything else is the same.
    :cool:

    [TABLE="class: cms_table_wikitable"]
    [TR]
    [/TR]
    [TR]
    [TH="bgcolor: #555555, align: center"]Stage[/TH]
    [TH="bgcolor: #555555, align: center"]Type[/TH]
    [TH="bgcolor: #555555, align: center"]UV set[/TH]
    [TH="bgcolor: #555555, align: center"]RGB[/TH]
    [TH="bgcolor: #555555, align: center"]Alpha[/TH]
    [/TR]
    [TR]
    [TD]1[/TD]
    [TD]Albedo Map[/TD]
    [TD]1[/TD]
    [TD]Classic albedo (low frequency details)[/TD]
    [TD]Low frequency Specular highlights and wet mask[/TD]
    [/TR]
    [TR]
    [TD]2[/TD]
    [TD]Multi Map[/TD]
    [TD]2[/TD]
    [TD]Asphalt detail map (high frequency details)[/TD]
    [TD][/TD]
    [/TR]
    [TR]
    [TD]3[/TD]
    [TD]Normal Map[/TD]
    [TD]3[/TD]
    [TD]Pronounces either stage 1 or 2 cracks or asphalt grain[/TD]
    [TD][/TD]
    [/TR]
    [TR]
    [TD]4[/TD]
    [TD]RaceGroove Map[/TD]
    [TD]4[/TD]
    [TD]Rubber racing line[/TD]
    [TD]Additive specular map for rubber highlights[/TD]
    [/TR]
    [TR]
    [TD]5[/TD]
    [TD]Specular Map[/TD]
    [TD]2[/TD]
    [TD]High frequency Specular highlights[/TD]
    [TD]Tileable puddle map[/TD]
    [/TR]
    [TR]
    [TD]6[/TD]
    [TD]Marbles Map[/TD]
    [TD]2[/TD]
    [TD]Rubber debris off racing line[/TD]
    [TD]Mask for marbles RGB[/TD]
    [/TR]
    [TR]
    [TD]7[/TD]
    [TD]Reflection Map[/TD]
    [TD]4[/TD]
    [TD]Placeholder cubemap[/TD]
    [/TR]
    [/TABLE]

    View attachment 20146
    View attachment 20147
    View attachment 20148
    View attachment 20149


    What you do in your moddeling program is up to you. But i think it's useful to make shader that resembles the end result. But you don't have too!!! Material name and UV's are the only thing that's needed.

    I've used a simple phong shader and plugged in a mix node that mixes the three textures (difuse, multi and race groove) they are all multiplied like you can do with photoshop layers. Those 3 are the UV sets, channels i want to visually see.
    UV 3 is just a copy of UV2. So Bump map and spec map i didn't had to assign them.
    View attachment 20151

    Just the basics are needed. So you can visually see the 4 UV sets, channels, mappings...

    View attachment 20150
     
  12. Woodee

    Woodee Registered

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    I'll try using the new editor in 3dsmax to see if I can get the same layout.
     

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