REFLECTING AND REFRACTING VIDEO POST EFFECTS
A 3D Studio Max Tutorial
by Jarek Dukat
http://www.nautilus.com.pl/jarek

This tutorial will show you how to reflect and refract Video Post effects like lens flares and glow. Techniques shown here can also be used also with other Video Post effects. Remember that only effects which are applied using Material Effect channel can be reflected/refracted.

REFLECTING LENS FLARES

Question about rendering reflected lens flares is one of the most often asked on newsgroups. You must know that reflecting lens flares doesn't occur in nature. But if so many people want to reflect flares, here's a few words about doing this.

Standard MAX 2 flares (LensFX) cannot be reflected. But it is possible with RealLensFlare (RLF) plugin. It has very many nice features, one of them is HighLight. This is a LensFlare but applied on object's surface, and only when the surface is bright enough. It can be applied via Material Effect channel, so it can also be applied on reflected/refracted surfaces. Here's how to setup a flare using HighLight instead of LensFlare:
First make an object that will cast the flare. It must be geometrical object, for example a small sphere. The object should be very small, the smaller the better, but it must be visible on rendered picture. You can turn off shadow casting for this object. Now prepare a material for it: diffuse, ambient and specular colors white (you can lock these colors in material editor so you have to modify only one color then). Use maximum Self Illumination (100). Also change Material Effect channel of this material to 1 or other value different than 0.
Now create the RLF HighLight helper object, and adjust it's properties. In Global Settings you should increase Min Intensity from 0 to 1 (or other non-zero value). Don't forget to setup channel thru which effect will be applied - you must use Material Channel. By default HighLight has only Star filter turned on, you should turn on more filters to make nice flare.
There is one more setting you must adjust so the highlight always appear on the object. In RLF options (they are available when you click Render icon under Scanline renderer settings, or in Video Post after you add RealLensFlare image filter event. You must decrease HighLight Face Intensity to 0, in other case HighLight effect won't appear or can appear just on a few frames during animation.

And now about object reflecting flares: its material must have raytraced reflection! Only Raytrace map and Raytrace material has ability to reflect Material Effect channel. Objects that has Flat Mirror used for Reflection slot or Raytraced material with non-raytraced reflections won't reflect material effects, so also Video Post filters won't be reflected.

If your materials and HighLight settings are all OK, your flare should be reflected like the one on sample picture below:

GLOW BEHIND TRANSPARENT OBJECTS

General rules of applying glow (and other Video Post effects too) behind transparent objects are same as above method for reflecting effects. But this time you don't need plugins - standard Lens Effect Glow from MAX 2 uses effect channels, so when applied via Material Effect channel it can be reflected and refracted. So, when you want to see Video Post effect from behind other objects you must use Raytrace map or material. Remember that if you apply Thin Wall Refraction or Auto Reflect/Refract map for Refraction slot it won't pass Material Effects channel and Video Post effects won't be applied behind transparent objects.
When using standard material with transparency: Increase material's opacity to 100, and apply Raytrace map for Refraction slot, and adjust Refraction Map Amount to appropriate value: 100 means that object is 100% transparent, 0 means no transparency.
When using Raytrace material: Adjust transparency amount in Basic Parameters and remember to turn on Raytraced Refractions in Raytracer Controls.
In both cases you will have to adjust Raytrace IOR (Index Of Refraction). This setting defines how much light rays going thru transparent raytraced object are dissorted. If you want no dissorted rays set it to 1.0.

Now just apply some Video Post effect via Material Effect Channel and that's it, done :). Below you can see a simple example of glowing objects behind other transparent object.

HIGHLIGHTS ON WATER SURFACE

Now in the end a few words about effect from picture below:

This is nothing else than a RLF HighLight. It was made using Automatic HighLight, but it can also be made using RLF HighLight helper or Lens Effect Highlight that is build in MAX 2 (but LensFX effect is less configurable and quality is not as good as RLF's). HighLight's settings are almost default and this is not reflected flare effect.

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