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BoeingGuy

Specular Lighting and Fresnel Lens/Ramp Effect

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Forgive my ignorance and inexpertise at this particular area.I was reading through an article that said all the new graphics FSX has to offer. I came across bump mapping (I know what that is), and the two things mentioned in the title. What are those two things and how can I experience them in FSX?Thanks!

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Specular maps on aircraft models basically control the shininess of of things, but they allow control on a per pixel basis rather than a global setting in a material like FS9 had. So with a specular map you can have say a black nose hood be a lot less shiny and 'glinty' than say a polished aluminum part. They can also be used to change the colour of the hotspot where the sun actually hits an object, making it slightly yellow or blue or whatever. In a specular map the RGB colour channels control the colour and intensity of the hotspot highlights and the alpha channel controls how sharp or broad the hotspot is. As an example both an orange and an apple are specular but an orange has a broader and lower intensity hotspot whereas the polished apple is much more 'specular' with a brighter smaller hotspot. Specular maps are great because unlike bump maps they cause very little performance hit.Fresnel ramps are used to affect a material or texture based on the angle of incidence between your view and the direction each polygon in the object faces. If you're looking at a ball then a fresnel ramp could be used to change how the part of the ball directly facing you looks vs how its edges that are facing away from you are shaded. So you could have the parts of the ball facing away from you tinted blue, and the rest red for instance. They can also control translucency in the same way. You can achieve some really amazing effects with them.You'll find them used in most of the default aircraft as well as most addons.Hope that pre-morning coffee explanation makes sense haha.-mike

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Hi,Specular lighting is quite simple: it's a way to specify how a material reflects light and how the reflections would appear. The graphic developer usually have 2 parameters that together control the appearance of the specular reflections. For example, glass will have a very small and defined reflection, while plastic will be more diffuse but more subtle. Have a look here for an example:reflection-blur.jpgOn the x and y axes, you can see the effect of the two parameter combined. They use different terms here for the name of the parameters, but they are usually called Specular Level and Specular ExponentThe Fresnel/Ramp effect allows for reflection to change their appearance depening on the angle of observation. The Ramp is usually a gradient of colors (but can be black/white as well) used as a lookup table to modulate the colors with a different value for different viewpoint angles.Fresnel Ramp effects are very well suited, for example, to simulate water surfaces.

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