Forum: Poser - OFFICIAL


Subject: SWieg was wanting a waterfall

skee opened this issue on Aug 18, 2000 ยท 8 posts


skee posted Fri, 18 August 2000 at 11:37 PM

I hope this image comes through. In an AVI file you will get a sharper water look. It was done with one texture and 2 onesided sq. If you want the texture and the details let me know. I will post it here. skee

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rwilliams posted Sat, 19 August 2000 at 7:06 AM

Please do! That is amazing. Very nice.


Jaager posted Sat, 19 August 2000 at 9:45 AM

There is just one thing about this sort of animation: The force of gravity is 32 feet per second per second. It is an acceleration factor - it is continuous ,but at 1 sec it falls 16 feet and 48 feet at 2 seconds. An interesting animation problem. The effect shown here is as though the water was flowing down a sheet of glass, with friction resisting acceleration. This is not to say that this is not nicely done. It is.


skee posted Sat, 19 August 2000 at 11:04 AM

Jaager, this is an antimated gif if you would like for me to sent you the avi file so you can see it in real action, it's only 40meg and with poser you can speed up the fall rate of one of the sufaces. Thanks for the information. skee

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Jaager posted Sat, 19 August 2000 at 2:52 PM

Thanks, but I am still at 43-48 thru my ISP. It is a little large. Cox says they will have the cable lines set around Dec. I did enjoy having the Think about the physics of falling water. That sort of thing is often so poorly taught that fascinating phenom are made boring. I was thinking about what the water must do to cover an ever increasing area as it falls - a sheet that is pulled ever thinner, until it breaks into globules. The globules stretched and shaped by friction with the air ever smaller until it hits bottom or reaches an equilibrium with its internal attractive force.


jeffheater posted Sat, 19 August 2000 at 3:38 PM

Jaager, are you saying the motion should speed up as it gets closer to the bottom? I guess that would add some more realism to it, but hard to get in a gif. skee- Great work, 40megs must have taken some render time, was it all done in poser?


Jaager posted Sat, 19 August 2000 at 5:30 PM

Yes, that is how it works. Real difficult to animate, I should think. If you were to do it, you would need to set it up as proportions (%) of the total distance per frame, and that % would increase with each frame, nothing about it is constant (except the rate of increase). If you did 10 frames per sec - the distance a water drop fell would be greater than the last in each frame and I think Calculus would be needed to work out what each % would be. You could not divide 16 feet by 10 and use that increment in each frame for the first second of fall. I do not remember how the equation is set up , but objects fall 16 feet the first second, an additional 32 feet the 2nd second for a total of 48 feet. Lets see, you can only do the calc as arthmatic in steps. I think at 1 second the velocity is 32 ft/sec, at second 2 it is 64 ft/sec, what? at second 3 it is 96 or 128 ? The velosity continuouly increases until the resistance of air forces an equilibrium. In a vacuum, it increases until the factor of its inertia becomes significant. A V2 was at 0 velosity at apogee and something like 2000 mph when it hit the ground and not because of its engine. If it had enough mass, it would not even need explosives to cause a lot of damage. Force = mass times velocity times velocity. Small rock from space moving really fast cause impart a lot of force.


schnaps posted Sun, 20 August 2000 at 1:46 PM

I was just wondering if anyone got anything out of these "physics" lessons. I could have used a simple explanation such as...things fall faster the longer they fall, instead of 3/4 of a page of details. Just wondering if I am the only one.