Hey guys! Smartpipe I have updated recently so if you haven't gotten the new version (it has a much higher resolution pipe) i suggest you try it. The pipes come in many different colors so you can select by family. The new version pf smartpipe tells you the family number when you select it in the library. I recently discovered that you can create custom named families and I wish that I had done this, I will be away from my main computer all summer and even so bryce 5 no longer works with OSX so no fixes there until i get 5.5a.

Anyhoo in the bottom of bryce there is the animation section. Hit the round white targer looking button in the lower right corner and the animation panel changes to the selection panel. Click and hold the square that looks like a gradient and go to select by family. Select the family that matches the color of smartpipe (make take a few tries because I didn't rename the families) and it will select the metaballs of that pipe only. That's why it comes in 8 colors, so you can have 8 different textured pipes without too much hassle.

Bryce paths have built in constraints and the can cause weird defects at extreme angles. Hold "T" "C" or "B" and then drag a point on the pipe to adjust the Tension (twist), Continuity (harshness), and Bias (left/rightness) of the curve around that point. This way it is much easier to be precise about positioning. Bryce paths always have one weird point that doesn't behave, you just gotta live with it :)

Zenith accurately boosts the saturation and contrast of the light to give realistic daylight without huge render times. It GREATLY improves the look of light through transparent objects as well as tree shadows. Disable the sun, and make sure your materals have little to no ambience. (Adjust ambience by decreasing/increasing shadow intensity in the skylab, and/or add small values of reflection to your materials). Create the zenith object (basic is fine from 45 degrees up to noon, use high res if you want better shadows at sunset/sunrise angles) and point it using the arrow. If it's too bright, your materials are too bright. The contrast of the light gives you a broader spectrum of materials to play with (100% is about 5 times brighter than 50% diffuse, as opposed to the usual twice as bright) so if you control your materials well, you can get a very realistic effect.

This scene uses both zenith and smartpipe in default render quality. Notice how the reflectivity of the brick material gives some life to the shadows. The bricks are two different mayang brick textures, one used for the terrain map, and the other I modified for use as the color map. Zenith does a good job here od capturing those very subtly soft shadows of the flowers against the brick.
I'll repost this as a FAQ.