Some new WIP images

Discussion in 'News & Notifications' started by 88mphTim, Jul 19, 2011.

  1. K Szczech

    K Szczech Registered

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    Well, static ambient o0cclusion on buildings etc. can be done in rFactor, but on the other hand - there are no tools that would let you do it.

    An artist would need to put such greyscale ambient textures on a model:
    [​IMG]
    An then put actual textures on it.

    In GMT files used by rFactor, each texture has it's own mapping (own UV set) and I think it's obvious that you need to use different UV for main texture and for ambient map.
    Unfortunately, neither 3D studio nor Blender, nor 3Dsimed can do that (even if rFactor can).

    On some smaller objects you can just darken main texture near corners and under roofs. It's far from perfect, but still better than entirely flat shading of interiors.
    This is how it's done with cars - ambient occlusion is added to car's texture.

    No.
    Amount of ambient light received by given object is controlled by "proximity of other objects" that may cover the main source of ambient light - the sky.

    So it's not about having some texture on an object, it's about knowing where other objects are. So no texture tricks will give you dynamic ambient occlusion or anything near it.
    Only static ambient occlusion can be done using textures, because if objects do not move, artist will know which parts will be darker.
     
  2. simfan

    simfan Registered

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    Looking at this image I'm sure that there is no ambient occlusion for now.
    Marked places should be darker.

    [​IMG]
     
  3. Alex Sawczuk

    Alex Sawczuk Member

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    There is clearly ambient occlusion there. Just rather light.
     
  4. Alex Sawczuk

    Alex Sawczuk Member

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    You can easily do it in 3ds Max, it's possible to do it with some shaders in default rf. I've done it a lot elsewhere too ;)
     
  5. Alex Sawczuk

    Alex Sawczuk Member

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    It would be pointless having a separate light map or ao maps on cars, as especially on the car body everything is mapped uniquely. It'd be a waste of shader operations.
     
  6. K Szczech

    K Szczech Registered

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    Yes. Although it's hard to tell if it's really some form of ambient occlusion or is it just texture that was manually darkened by artist.

    Yeah, 3DS MAX probably can, but .3ds file format cannot support multiple UV sets, and 3DSimEd does not support .max file format AFAIK.

    But of course you can just use vertex colors instead of ambient texture.

    Not really.
    Proper shadowing equation is like that:

    pixelColor = (colorMap * diffuseLighting + specularMap * specularLighting) * shadowMap + colorMap * ambientMap * ambientLight

    Note that shadowmap affects diffuse and specular lighting only and ambient map affects ambient lighting only.

    Some games still make the mistake of doing it like that:
    pixelColor = colorMap * (diffuseLighting + ambientLight) + specularMap * specularLighting
    And then they darken previously rendered scene where shadows and ambient occlusion is.

    That's incorrect, because you will still be able to see, for example, specular reflections inside a shadow or have directional/specular lighting weakened where ambient occlusion is.
     
    Last edited by a moderator: Jul 22, 2011
  7. dragon

    dragon Registered

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    Again, no announcement fulfilled a movie?
     
  8. mclaren777

    mclaren777 Registered

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    I'm eagerly hitting F5 every 30 minutes hoping for some videos. :)
     
  9. YoShImUrA

    YoShImUrA Registered

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    Thanks for answering, Tim. Although I agree with your point, how many times you've been blinded in the morning/afternoon/evening by driving towards the sun (no sunglasses to wear) and this intense light prevents you from being able to properly watch the road or the other cars in front? that is what I was talking about that it would be great to have in some kind of way for dawn/dusk racing... =)
     
  10. sg333

    sg333 Registered

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    Tim said no ETA on the last page

    Tim, are we talking hours/days/weeks for the new video??? :D
     
  11. Alex Sawczuk

    Alex Sawczuk Member

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    You should be using the proper tools. 3dsimed is useless if you want to do anything properly.
     
  12. MaXyM

    MaXyM Registered

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    Yeas, that's why he write own tools ;)
     
  13. mianiak

    mianiak Registered

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    Getting a bit off topic here, but for the record, Dave put a paste uv co-ords button in simed, if you have to use .3ds, save duplicate models with all different uv's, you can then copy and paste them to the desired layer in simed.

    Back on topic, so ambient occlusion would be a mix of shadow, reflected light, ambient light and direct light? I see why this wouldn't work with just a bump map (just when I thought I was getting an understanding of how shaders work dynamically :D ). I wonder how the real time reflection will play in this. If you have a building with a white path out the front it should light up the front of the building more so than if it were a black path yes? If that's the case and if that is possible to do, then you really don't need an ambient occlusion shader cause the environment will generate its own.
     
  14. 88mphTim

    88mphTim Staff Member

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    As I said in a previous post there really is never one light source. Light bounces and this occludes shadowing.

    The photo of the manikin someone posted, if there was truly one light source, the shadow on the face would have been an absolute black because the light from the sun wouldn't reach it, but it does because it bounces off objects. The most direct route being sun - face - back of hand - back onto the face ontop of the shadow.
     
  15. 88mphTim

    88mphTim Staff Member

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    There may have just been some texturing for what you're seeing. I don't think it's in yet.....
     
  16. 88mphTim

    88mphTim Staff Member

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    A week maybe. :)
     
  17. MaXyM

    MaXyM Registered

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    imo ambient occlusion is result of presence of ambient light. Not multiply-times reflected direct one.
     
  18. 88mphTim

    88mphTim Staff Member

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    That's what ambient light is. When you're outside on a sunny day it certainly isn't any other light source than the sun is it? :)
     
  19. MaXyM

    MaXyM Registered

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    Yes, sun is one and only light source. But ambient occlusion is affected by sunlight dispersed by the atmosphere rather than reflected

    In other words, day is bright because the sky is 'shining'. Not because sun is reflected by trees, buildings, your hand etc
     
    Last edited by a moderator: Jul 22, 2011
  20. 88mphTim

    88mphTim Staff Member

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    I think we're both saying the same thing actually. I think both types of reflected light have big roles to play in lighting our surroundings, but it's important to know that anything a human looks at is always pretty close to some other object (usually ourselves), and our skin, our clothes, really affect what we see. If you make a cone shape out of non-reflective black card, lay on the ground to minimise the light getting in and look up into it, I guarantee you can see inside the cone. This will be the light bouncing off your face lighting inside the cone.
     

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