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    Question about dynamic lighting

    I have a question about dynamic lighting. In particular, it is about two settings: Light Brightness and Light Radius and how the interrelate (I’m at work, so forgive me if this isn’t exact wording, but if you worked with this, you know what I mean.)

    Does changing the brightness change the light’s perceived (as seen by the players) radius, as it would in real life (e.g.: a dimmer light has a smaller area [radius] of effect whereas a brighter one would have a greater one)? Or, rather, does changing the light’s brightness simply increase or decrease its luminescence within the pre-defined radius setting?

    Or, to put it another way… Let’s assume that you have a brightness setting of 64 and a radius of 64, so you have a particular look -- an area of effect the players see, if you will. Now change the brightness setting to 128. Question is, does changing this setting mean that the light’s effect will now exceed the area of effect that is “seen” by the players, even though the radius is still 64? Or, does changing the brightness (but not the radius) simply mean that it will be brighter within the pre-defined radius?

    #2
    Brightness = brightness
    Radius = radius

    A 10 second test could have told you that.

    Comment


      #3
      Not to be (too) dense...

      (And yes, I'll test it when I get home. The question just now occured to me at work.)

      So increasing the brightness DOES NOT, then, increase its actual visible radius in game (as it would in Real Life[tm]) -- it simply increases the luminosity within the predefined radius. Right?

      Actually, "visible radius" still may not be an accurate desciptor -- considering that you may be able to see the source from clear across the map...

      A better way of putting it is that the distance a light's impact has on its surroundings (shadows cast, how it reflects off surfaces, etc.) is strictly definied by its radius, regardless of its brightness setting, as defined in UEdit. Right?

      Comment


        #4
        Originally posted by PapaBear
        A better way of putting it is that the distance a light's impact has on its surroundings (shadows cast, how it reflects off surfaces, etc.) is strictly definied by its radius, regardless of its brightness setting, as defined in UEdit. Right?
        Exactly. Basically, the radius determines the limit of where a given light source is taken into account when calculating the lightmaps and other lighting effects.

        There is also a limit on how many light sources are taken into account when making some calculations (vertex lighting on static meshes has, I think, a limit of 6 light sources affecting each vertex). So it's possible for some lights to have no effect even on a mesh within their radius.

        Comment


          #5
          I always assumed brightness = intensity.

          Comment


            #6


            OK, I'm home so I did a little test. I set up a small map with a series of columns (8 in all), put a single light source in it, and simply changed its brightness, and not its radius (which I kept at 64).

            I also had all my graphic settings set to their highest.

            At a brightness of 64, you easily see 1 and 2, and you could barely see 3 and not 4 at all.

            At 512, you can 1, 2 and 3, with 4 barely lit.

            In the image, the brightness is set to 1024, and you can see 1, 2, 3, and 4 clearly.

            Now setting this above 1024 didn't make a lot of difference (other than making the objects that were already illuminated brighter), and at no time was column number 5 (or greater) visible.

            So...

            The radius does, indeed, limit the effect the light has things, unlike real life (RL). In RL, a brightness of 2048 (or 4096, as I also tried) would have "lit up" columns 5 through 8.

            However, there is an apparent "real life" effect when you take the lower brightnesses into account, within the defined radius. I.E.: #4 wasn't lit at all when the brightness was set to 64, and it was when the brightness was set to 512. I do suspect that the light was having some impact on #4 at the 64 brightness setting -- it just wasn't apparent to me due to its "dimness". It is also possible that my Radeon 9800Pro video card couldn’t render anything meaningful to my eye in terms of visibility.

            Wouldn't it be cool, then, if we could set the radius to, say, zero and let the light's brightness determine the radius of its effect? I say zero, because I can still see circumstances where limiting a light's radius, regardless of its brightness setting, can be useful and beneficial.

            Of course, I'm not a programmer, nor a low-level hardware geek. So while I suspect this can be done on a programming level, I don't know if the programming would be overly complicated or if today's (user level) hardware can support such a thing.

            Thanks for putting up with my rambling this morning.

            Comment


              #7
              No, the lighting system is good how it is. :bulb:

              Just use the radius and brightness in conjunction with each other. Lighting in UEd is not that difficult.

              Comment


                #8
                Originally posted by PapaBear
                Wouldn't it be cool, then, if we could set the radius to, say, zero and let the light's brightness determine the radius of its effect?
                If you were happy to wait 3 days for a map to build, perhaps. If all the lights have infinte falloff (the effective falloff determined by the brightness), then there's nothing to determine a cutoff point, so the build process would have to raytrace from every light in the map to every surface and object.

                Comment


                  #9
                  Well dynamic lighting is all fine and good, but i cant seem to make it work in my maps or on my vehicle.....

                  Trying the different styles and effects, strobe, pulsate, flicker, and rotor dont seem to work for me, my dynamic projectors dont light up correctly, is this a UT2004 problem, or (more likely) a me problem?

                  Comment


                    #10
                    DaJMasta,

                    The light styles and effects have been disabled - sort of - what has actually happened is that they've changed from the simple dynamic lightmaps of UT to more detailed, but pre-calculated, lightmaps - which means that the light actors can do whatever they want, but it will never show the effects in game because the lighting was fixed when the map was built. There are a couple of ways around it, by replacing the lights with either TriggerLights or Emitters (which work because they still have their own dynamic raytracing code), but even then they still don't support the full range of effects.

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