CompuServe Thread

Hi Jonas: I just finished downloading the file you sent me. Thanks a lot! <Are you saying that there are no sphere's in the scene? Are you creating hide keys for the water particles to help delineate their shape? > The explanation you are interested in follows this "how I did it note": ————————————————————– The "continous looping" was done with AniPro. On a whim I decided to see what it would look like without spheres. Continuing w/Ani-Pro I removed three yellow spheres. The water that flowed over the spheres, being transparent, picked up some color from the spheres. I corrected that also. The color shifting I did, was discussed in the description of "AniPro Secret #3 (Fire 16). There is no further discussion in the animation itself. Another example of color shifting, (I think all three animations use the same palette) can be seen in 3GA54.ZIP, "Negative friction": <From the description : " … Look carefully at the fire under the water, it's simply a clone of that same water. Merely, "water of a different color." … > ————————————————————— Back to your question. That animation was generated with a script for a particle system. I'll be uploading a script for "A Simple Particle System" as soon as I get some feedback from my "beta-testers" {hint!!!}. You are hereby sworn to secrecy (until the final version is ready) and I am E-mailing you a copy. The description of "ASPS" is attached. In it is explained how the collisions are handled. There is no need for ANY 3ds objects to exist, other than the fact that keys are created for them. The motion of the objects is just the way the script shows you the values it has computed. It could just as well not tell you (a "compute only" script), or just print them: ; Detailed Description ; ~~~~~~~~~~~~~~~~~~~~ ; This script implements a simple particle system with one body and several ; particles. You need to provide objects for the particles and the body. The ; name of the particles should be "Part…". The name of the body should be ; "Body…". ; ; The script computes the position and velocity for each of the objects once ; per frame. It tells 3ds where to place the objects by creating position ; keys. ; ; The body can only be placed on the x-axis, and can only move along that ; axis. Its initial position and velocity are set by: Body_x_pos = 120000: Body_x_vel = -20000: ; You can place the particles in their initial positions yourself, or have ; the script place them in random positions within a box centered at the ; origin. The choice is made with: Place_part$ = "YES": ; and the size of the particle-box is specified by: Box_edge_x = 12000: Box_edge_y = 12000: Box_edge_z = 12000: ; The initial velocity for the particles along the x-axis (the velocity ; along the y and z directions is always initialized to 0) is set by: Part_x_vel = 0: ; You can control which particles are visible with: Show_part$ = "ALL": ; You can specify either "ALL" or "POS." If set to "POS," only particles ; with positive X-velocity are displayed. ; ; Collisions between the body and the particles are handled with a field ; that surrounds the body. Particles near the surface of the body experience ; a force away from its center. The magnitude of the field increases, ; without bounds, toward the center of the body. This approach produces a ; soft "surface." The strength of the field is set by: Field = 4*10^14: ; The values used above result in the body crashing into the particles and ; creating a symmetrical explosion. The fact that the objects do not ; interact between frames, was used to make the explosion symmetrical. ; Values were chosen that result in the body landing exactly in the middle ; of the particles on frame six and to be too far away to significantly ; affect them at all other times. ; ; When the particles suddenly find themselves inside the body/field, the ; result is explosive. Note, however, that the result is not very accurate. ; A particle could end at the center of the body, an event that should ; require a collision at infinite speed. To simulate the collision more ; accurately, the speed of the body should be ; decreased; the slower, the better. ; To use other values experiment with the values of the parameters. ; You'll be surprised at the large number of effects that can be ; achieved with a particle system, even one as simple as this one. ; ; ; The following values were used for "SPRAY.ZIP" ; ; Body_x_pos = -13000 ; Body_x_vel = 0 ; ; Place_part$= "YES" ; Box_edge_x = 20000 ; Box_edge_y = 300 ; Box_edge_z = 300 ; ; Part_x_vel = -1000 ; Show_part$ = "POS" ; ; Field = -2*10^12 ; ; The following values were used for "BLOW.ZIP": ; ; Body_x_pos = 3000 ; Body_x_vel = 0 ; ; Place_part$= "NO" ; Box_edge_x = 1 ; Box_edge_y = 10000 ; Box_edge_z = 10000 ; ; Part_x_vel = 0 ;Show_part$ = "ALL" ; ; Field = 2*10^11 ;

<I wish the water occupied more of the screen. > Every now and them someone (Ara Gregorian comes to mind) wants bigger animations. Fortunately you guys let me know, because I also get requests for smaller animations. Just recently, I received a request (by E-mail so I won't mention names) for uploading smaller TSE-generated animations (which was directly responsible for some of the water in "Water!" being removed). What I upload is mostly the result of feedback. You'll see more water! Ed K