OverFlow Tutorial
By: Jim Marten
2. Open Particle Storm2.
3. Click on Simulation in the Items view, and set Stop Time to 10 s.
4. Set OverSampling to 3. This will slow down the simulation speed, but will make the collisions much more accurate.
Rename the Particle Group for this simulation. Also, designate the amount of particles for the simulation, and create the .lwo file for the group.
5. Click on the Particle Group named Pgroup in the Items view.
6. Rename it to OverFlow.
7. Set the Number of Particles to 750.
8. Click on the File Requester button-
- Choose the directory you would like to have your .lwo and .psm files stored
- Type "OverFlow" for the name.
9. Right click on OverFlow in the Items view under Particle Groups, and select Create Effect Object.
The collision parameters for the cup
Create the Collision Objects for the simulation. Create a Cup the particles will fill, and create a Floor for the particles to fall onto.
10. Right click on Controllers in the Items view and select Collision.
11. Change the name of the newly created Collision Object to “Cup”.
12. For Shape Type, select LW Object. Click on the File requester button, and select the SquareCup.lwo from the objects directory in the OverFlow tutorial directory.
13. Parent the Position of the object to the Layout item SquareCup.lwo by right clicking on Position, then selecting SquareCup.lwo from the drop down list.
14. Parent the Scale of the object to the Layout item SquareCup.lwo by Right clicking on Scale, then selecting SquareCup.lwo from the drop down list.
15. Change the Elasticity value to 0%. We do this so the particles don’t bounce around too much inside the object. The Particle Field will already cause the particles to bounce around, so we don’t need them to bounce off the cup.
16. Set the Roughness to 5%. This puts a little bit of drag on the particles as they are climbing over the top of the object, rather than just skating over it like the object was made of ice. 17. Again, right click on Controllers in the Items view and select Collision.
18. Change the name of the newly created Collision Object to “Floor”.
19. For Shape Type, select LW Object. Click on the File requester button, and select the Cube.lwo from the objects directory in the OverFlow tutorial directory.
20. Parent the Position of the object to Cube.lwo by right clicking on Position, then selecting Cube.lwo from the drop down list.
21. Change the Elasticity value to 0%.
22. Set the Roughness to 5%. This puts a little more drag on the particles after they land on the object, to keep them on the object, rather than just sliding over the edge.
Set up the emitter that will dispense the particles.
23. Click on the Fountain Controller.
24. Set Birth Rate to 200 particles/sec, so the particles are emitted slowly.
25. Set Position- X: 0; Y: 0.75; Z: 0.
26. Set Orientation- Heading: 0 deg; Pitch: 90 deg; Bank: 0 deg.
27. Set Scale- X: 0%; Y: 0%; Z: 0%.
28. Set Minimum Speed to .1 m/s and Maximum Speed to .2 m/s.
The Particle Field parameters
Adding a Particle Field will cause the particles to react with each other and give more of a liquid type effect.
29. Right click on Controllers in the Items view and select Particle Field.
30. Change the Happy Radius to .08 m. This is the distance that dictates when particles will repel each other. When 2 particles come close to each other, they will repel each other if their Happy Radii come in contact. Increasing this value will make the particles want to stay farther away from each other.
31. Decrease Attract Strength to .8.
32. Set both Attract and Repel Falloffs to 4.
33. We only want Particle Field to affect the particles after they’ve fallen into the cup, so we want to use a Bounding Shape. Turn Bounding Shape on and open the parameters by clicking on the red triangle next to the Bounding Shape property.
34. Set Shape Type to Box.
35. Set Scale- X: 400%; Y: 30%; Z: 300%. This creates a box that will be tall enough to encompass the cup, and long and wide enough to cover the whole floor.
36. We want the particles to sit in the bottom of the cup, then slowly fill it up. In order to do this, we envelope the Bounding Shape Y Position so it starts at the bottom of the cup, and slowly moves its way up to the top of the cup. This activates Particle Field on the particles that the Shape moves over. As the particles repel each other, the cup is gradually filled with particles. Open the Position Parameter and under Y, select Envelope from the drop-down list (rather than Constant). Click on Edit Envelope, then load OverFlowPF.env.
Add a Force Field to pull the particles towards the center of the cup and cause them to dribble down the side of the cup.
37. Right click on Controllers in the Items view and select Force Field.
38. Set Shape to Line so we have a line going through the middle of the cup.
39. Set Strength to –1.7 N. This will pull the particles towards the middle of the cup.
40. Set Y Value of Orientation to 90 deg.
41. We only want the Force Field to affect the particles in a specific area, so we will set up a Bounding Shape. Turn Bounding Shape on.
42. Click on the arrow next to Bounding Shape to open the parameters for this property. 43. Select Box for Shape Type.
44. Set Scale- X: 40%; Y: 18%; Z: 40%. This will scale the box down to the size of the area we want the Force Field to be active in.
45. Click on the arrow next to the Position parameter. Set the Y Position to 0.32 m. This will position the bounding box right at the top of the cup.
Add Drag to put a damper on the particle's movement and stop them from bouncing around violently in the cup. This also helps prevent the particles from shooting away from the cup when they climb over the edge.
46. Right click on “Controllers” in the Items view and select Drag.
47. The only thing we need to do with this Controller is increase the Drag Coefficient to 20. This will put lots of drag on the particles and slow them down considerably.
48. Record the simulation by returning to frame 0, pressing Record, then Play, and letting it run to the end. This may take quite a bit of time, due to the number of calculations necessary for both Particle Field and the Collision Objects.
49. Go back to Layout, and load the OverFlow-Render.lws scene. This scene moves the Floor object down .02m to compensate for the HyperVoxels effect.
50. Add your created OverFlow.lwo object, and apply the Particle Storm Displacement Map Plug-in to it.
51. Click on Options, then click Load PSM File, and load your created OverFlow.psm file.
52. Close the Particle Storm Displacement Map Plug-in panel.
53. Add the HyperVoxels(Particles) Displacement Plugin. Click on Options, and Select ParticleStorm from the drop down list. Make sure none of the Particle Information boxes are selected.
54. Go to the Effects Panel, and Select the HyperVoxels Pixel Filter Plug-in.
55. Go to the Options Panel:
- In the Objects drop-down list, select OverFlow.lwo, then click the Activate button.
- Click on the Presets button and select the green flubber preset.
- Under Size Parameters:
- Select Absolute Sizing Mode.
- Set Particle Size to .05, and Size Variation to 30%.
- Under HyperTexture Options:
- Select HyperTexture Fractal Bumps
- Affect: Geometry
- Frequencies:4; Scale: 70%; Amplitude:100%; Filter: Sine2; Gain: -35; Bias: 30
56. Go to the Objects Panel and select OverFlow.lwo. Open the Options panel for the HyperVoxels Displacement Map plug-in and ensure once again that the Particle Information boxes are not selected.
57. Move the Scrub bar to frame 150 and Render that frame.
Quick Tip:
To create a volcano type effect, make the following changes to your Particle Storm2 project:- Deactivate Force Field and Drag by right clicking on them in the Controllers sub-tree, and selecting Activate/Deactivate.
- Select the OverFlow particle group, and rename it and its Effect File Base to Volcano.
- Change the Number of Particles to 500.
- Create a new .lwo file the same way you did in the first section of the tutorial.
- Select the Fountain controller
- Change the Birth Rate to 1200 particles/sec, and the Y position to .2m.
- Select Particle Field and open the Affected Particles Property. Select Envelope from the drop-down list.
- Click on Edit Envelope, then load the VolcanoPF.env from the OverFlow Tutorial directory.
- Under the Bounding Shape Position, remove the Envelope from the Y Position and make it a Constant .2m.
- Record the simulation.