If you're having trouble with frame rates and the effect is causing FS2002 to slow up, there are a couple of solutions, both of which require modifying the Snow.fx file (see below). Just remember that using these effects will naturally cause a reduction in frame rates because of the moving textures on the screen. The reduction can be significant on slower systems and is probably the reason why Microsoft did not use these special effects to the fullest extent in FS2002. When creating these effects I tried to use textures with low resolution and a minimum amount of detail. If you view these textures with Paint Shop or a similar program, you will see that they are plain and boring, but for good reason. My system specs are as follows:
Athlon AMD 1Ghz
Geforce Ti200, over clocked to 193/430
640MB SDRAM
I did most of the testing in desert areas (to reduce texture loading time) with little or no ground scenery around. Every time you make an adjustment to the effects file, you need to shut down and restart the sim and at times this can be tedious. I set my frame rate lock at 40 FPS, then at 20FPS. The result was the same. My frame rates with this effect hovered around 14 to 15 FPS. It would be nice if I could incorporate the snow into FS2002 without using the smoke system, but it's all I can think of for now.
WARNING:
Task switching and using the map view sometimes accelerate the accumulating snow. I have no idea why, but it creates an unrealistic blanket of white.
THE FLOATING TEXTURE PROBLEM:
First of all you should notice that the snow accumulation does not cover every square inch of the ground and what it does cover is very light. The reason for doing this was to avoid slower frame rates and unrealistic clutter on the ground. As a result, the effect is somewhat subtle.
The snowfall textures that are emitted by the effect are supposed to remain on the ground and never rise off the ground. The problem is the emitter assumes the textures will settle to the ground level where the plane is. The result is floating textures in areas of dramatic altitude changes. If the airport elevation is 500ft where the plane is sitting, and the terrain immediately surrounding the airport is 300ft, then the textures will still appear at 500ft floating 200ft above the surrounding terrain. This is not very noticeable when taking off from the airport because everything is still below you. It is, however, noticeable when descending into varied terrain where the ground level is constantly changing or dropping. My suggestion would be to turn the effect off after takeoff and turn it on again just before landing.
Two adjustments to the Snow.fx File:
Under the section [Emitter.0] or [Emitter.1] there is a line that says Rate=x,x that looks like this.
[Emitter.0]
x
x
Rate=200.00, 300.00
(Particles are emitted at this rate. The first number is the min., the second is the max.)
You can change the rate of particles emitted by reducing this range to,
Rate=100.00, 150.00
or variations of that.
The other adjustment is eliminating the snow falling from the sky (not the snow accumulation).
Eliminate the following SECTIONS
[Emitter.0], [Particle.0], [ParticleAttributes.0]
and rename the LINES
[Emitter.1], [Particle.1], [ParticleAttributes.1]
to
[Emitter.0], [Particle.0], [ParticleAttributes.0]
The Special Effects SDK describes these special effects and controllers for effects (not used in this version) as a powerful tool, with the only limitation being the impact on frame rates. Any texture (mostly transparent ones) can be modified and resized to create outstanding effects. The SDK is, for the most part, helpful in tutoring a beginner and I encourage everyone to experiment and create.
