Animating the Sand Level with Slice Modifiers

Creating a Realistic Hourglass

Creating the Sand Build-Up

 

Autodesk 3ds Max Tutorials >  Modeling Tutorials > Creating a Realistic Hourglass > 

Animating the Falling Sand

Particle systems create effects that would be too laborious to make using geometry.

Create the particle system:

1. Continue from the previous lesson or open sands_of_time3.max from the \tutorials\hourglass directory.
2. Select the sand in upper globe object in the viewport. Make sure you see its name in the Name field, then right-click and choose Hide Selection.

   This hides the sand.

3. On the menu bar, choose Create > Particles > Snow.
4. In an empty area of the Perspective viewport, click and drag outward to create a Snow emitter.

   The emitter specifies where the particles are generated.

   

   Snow emitter

5. Play the animation and watch the snow particles in the viewport.

   

   Play the snow system animation.

6. On the toolbar, click the Select And Move button, and then enter in the Coordinate Display:
   • X=0
   • Y=0
   • Z=30
   TipTo quickly set the X and Y axis coordinates to 0, right-click the spinner arrows.

   The Snow emitter moves to the correct location at the neck, separating the top and bottom chambers of the hourglass.

7. On the Modify panel > Parameters rollout, in the Emitter group, set the Width and Length values of the emitter to 1.5.

   

   Snow particle system falling through the neck

Create space warps:

You can use space warp objects to control the particles in various ways. You'll create two different space warps: Gravity and UDeflector. Gravity gives you better control over the particles' downward motion, and UDeflector will prevent the particles from passing through the bottom of the hourglass.

1. On the menu bar, choose Create > Space Warps > Forces > Gravity.
2. In an empty area of the viewport, click and drag outward to create a Gravity space warp.

   The placement of the space warps is not important; you can put them anywhere in the scene.

3. On the menu bar, choose Create > Space Warps > Deflectors > UDeflector. In an empty area of the viewport, click and drag outward to create a UDeflector.
4. In the Basic Parameters rollout, in the Object-Based Deflector group, click Pick Object, then in the viewport click the bottom plate (ChamferCyl02) of the hourglass.
5. In the Particle Bounce group, set Bounce to 0. This lets the particles “collect” on the UDeflector.
6. Select the Snow emitter in the viewport.
7. On the toolbar, click the Bind To Space Warp button, and then drag from the Snow emitter to the Gravity space warp.

   

   Binding the Snow emitter to the Gravity space warp

8. Repeat the process for the UDeflector, binding the Snow emitter to the UDeflector.

Adjust the appearance:

1. Click the Play button to play the animation.

   You'll change the appearance of the snowflakes so that they look like falling sand.

2. Stop the animation. Select the Snow emitter in the Modify stack, then in the Parameters rollout, enter these settings in the Particles group:
   • Viewport Count: 375
   • Render Count 888
   • Flake Size:0.8
   • Speed:0.5
   • Variation:0.5
     WarningIn general, it is not a good idea to increase the Viewport Count very much. This can seriously slow down 3ds Max. If you do increase the Viewport Count, don't use the spinner to do so. If you inadvertently set the spinner to a very high amount, you could incur a long wait. Always enter the values using the keyboard or number keys.

   Next you'll make an adjustment in the Timing group.

3. In the Timing group, turn off Constant. Set Life to 60 and Birth Rate to 1.0.

   

   The snow is under control.

Animate the falling sand:

1. With the Snow emitter selected, open the Material Editor (if it isn't already open), and select the Sand material, then click Assign Material To Selection.
2. Right-click the viewport and choose Unhide All, and then play the animation.

   

   Sand made from particles and animated Slice modifier

   To make the effect of the particles disappearing, you'll animate the Birth Rate of the particles.

3. In the animation controls section, near the lower-right corner of the interface, click the Time Configuration button. On the Time Configuration dialog, in the Animation group, set Length to 120. Click OK.
4. Click the Auto Key button to activate it, then with the Snow emitter selected, move the time slider to frame 102.

   In the Parameters rollout, change the Birth Rate to 0.0. This stops the particles emitting at frame 102, since the birth will stop.

   The particles that were already emitted will continue to fall.

   Next you'll move backwards in time to where the sand in the upper chamber is getting smaller and the stream in the lower chamber needs to be stronger.

5. Move the time slider to Frame 86, and set the Birth rate to 6.0.

   This ensures a solid fall of sand at this frame.

6. Move backwards to Frame 78, and set the Birth rate to 5.9.

   This keeps the falling sand falling.

7. Move backwards to Frame 15, and set the Birth rate to 6.9

   This adds momentum to the falling sand.

8. Move backwards to Frame 0, and set the Birth rate to 5.0.

   This keyframe starts the fall of the sand while the sand level drops in the upper chamber.

9. Move the time slider forward in time to frame 106 and set the Birth rate to 1.

   This will allow you to set a key at frame 106. Once the key is set you'll change its values using the track bar right-click menu.

10. On the track bar, select the key at frame 106, right-click and choose Snow01: Birth Rate from the list.
11. In the Snow01 Birth Rate dialog, change the Value to –52 and set the In and Out tangents to Smooth.
    NoteThe tangent settings, which determine the relative motion immediately before and after the key, are represented by the large graph buttons at the bottom of the dialog. These buttons act as flyouts; click and hold on a button, and then drag to the new setting. The Smooth tangents are shown in the following illustration.

    

    This works to end the stream of falling sand.

12. Turn off the Auto Key button and then play the animation.

    The sand descends, the stream falls in concert with the sand in the upper chamber.

    

    Sand falling at frames 15, 86 and 120

    If you had any trouble, you can open sands_of_time4.max to see the file with the correct settings. It's easy to miss a step or make a mistake and not get the correct results.

13. Save your work as MyHourglass6.max.

Next you'll use an animated hemisphere to create the sand building up in the bottom of the lower chamber.