CompuServe Thread

\exit Hi David, How strange. I don't believe I've ever paid much attention to a humpback whale before – never even created an underwater scene I don't think. After viewing your images and posting my message about 4-5 a.m., I had to be somewhere at 9:30 still very much asleep, still thinking about your fine images, and what jumps out at me when I visted their bathroom ? A huge sculpture of an adult & baby humback whale attatched to a coral reef. Very strange feeling. Anyway: >>I'll be picking up the flock routine when I get to the reef scene to do schooling fish. What's your opinion on it? How much control do you have over the movement of the objects and is there a complexity limit on the mesh used as the master particle? While I have very limited experience with any of the IPAS stuff and 3DS in general, I will attempt to answer your questions: I have mixed feelings about it. While initially disappointed that it did not actually perform collision detection (neither specific nor interactive), I have found it to be useful after doing about a dozen tests or so. As long as the particles are small and/or don't come too close to the camera you're o.k.. Of course, you can set up the anim and render a simplified flic test over & over, changing parameters as neccessary until you get something in which no surface penetration happens to be visible (very tedious). I had to do this with the couple of fish anim tests that I referred to using projector lights, etc.. An underwater scene with other elements viewed at close range is probably one of the more difficult applications to set up utilizing this routine. (I believe schools of fish tend to have less vertical motion than birds in flight, bees, etc.. – that sort of thing) Specifically, the particles must be a single object (any elements attatched, no heirarchy), can be texture mapped, and all particles combined cannot exceed 64k faces. There are many (almost too many) parameters to control flocking characteristics, speed, turn speed, chaos, ground/ceiling repulsion, etc.. Beware that the particles can "escape" the bounding cube in some situations, though. A rather handy feature is it's ability to "set the clock backward" by assigning a negative start frame which lets the motion develop a bit before the start frame. You can also have control to allow network rendering which actually is pretty tricky with any time-based procedural animation, as a given frame can not be calculated without knowing all particle positions/vectors, etc. from a previous frame. Also, most interesting flocking simulations require several hundred frames minimum to be effective, epecially fish from my experiments. You can achieve many different patterns, including straight-line migratory types with a LOT of experimentation. Particles can only rotate around the pitch & yaw axes, and orienting a recognizable object to seed the flock can be tricky, again, especially with fish (if the camera is down there with them above and below as opposed to "looking up" only at birds, etc.. All things considered, it's probably worth the hundred bucks. It would be *VERY* nice if the particles could have a simple heirarchy and cyclic motion such as wings flapping, fish undulating, etc.. CD would be nice too of course, but very "expensive" w/r/t devolpment & rendering time. For schools of fish, keyframed animation with transformed instances MIGHT be easier/quicker for relatively brief shots of the fish. For longer scenes or birds, bees, etc., it's very handy. I hope this has been of some help, rather than confusing. Tell you what, I'll try to upload a small, simple flic (50-60 frames) from the first test I did which also shows the bubbles, caustic projections, some fish etc. if you won't laugh and I can make the following disclaimers:<g> * NONE of the elements' motion/timing, etc. are nearly worked out (first test). * No texture mapping * No antialiasing * No other elements in scene * The dolphin geometry was done in a few minutes and it's anatomy/motion is not valid * There are a few fish flocked briefly in the scene, but it can get much better. * etc., etc., etc…… This was only a first test actually for the projector light and for the "swimming out of fog" effect; I just threw in the other stuff while I was at it. They're not ideal either, but you'll get the idea. Even with all of this simplification, and only 240×180, it' will still probably be half a megabyte or more. I'll try to make it as small as possible. Take a look if interested. W/R/T the Bubble.axp, I've found it difficult to control precisely, such as bubbles coming out of the blowhole (is that right ?) of a moving whale, dolphin, etc.. Mainly due to the fact that a shaping object must be a closed loop when brought into the editor (then used as a path in K/F). Have you had good results from this sort of thing ? Do you know anything about the Blackbox bubble.axp as it relates to this ? The "unroll mesh" IPAS will do the trick I believe, properly implemented.