Simulating Water with MetaParticles

MAX has eight standard particle types available to the Super Spray system. It also allows you to assign MetaParticles and instanced geometry to the Super Spray system. MetaParticles are particles that cling and regroup based on their distance from each other, creating a more fluid-like effect. For our animation, let’s try MetaParticles.

1.  Close the Particle Generation rollout and open the Particle Type rollout. In the Particle Types and Standard Particles sections, you can see that currently we have Triangle standard particles. Check MetaParticles and render the perspective viewport again. Your render should look something like Figure 11.31.

FIGURE 11.31  Render of particle system with MetaParticles

Now that we have something more fluid, let’s adjust other Super Spray settings to get the effect we want.

2.  Right-click an empty area of the Modify tab. From the shortcut menu, select Basic Parameters. In the Particle Formation section, set the Off Axis value to 5, the first Spread value to 16.5, the Off Plane value to 40, and the second Spread value to 180. You may want to take some time to play with these parameters to see their effects before setting them to these values. Render to check out their effect; it should look like Figure 11.32.

3.  Set the Percentage of Particles to 50. This is the percentage of the particles that will appear in the viewport. It won’t affect the rendering output; it just makes the viewport display faster.

To make the water burst out of the faucet, let’s adjust the particle speed.

FIGURE 11.32  Our particle system is looking more like water.

4.  In the Particle Motion section of the Particle Generation rollout, set the Speed to 1". This is the distance the particles travel in a frame. Set the Variation to 50 to create variations in emission speed between particles up to 50 percent. Under Particle Timing, set Display Until to 136 so that the particles will remain visible until frame 136. Set Life to 42. This is the lifespan of each particle from the time of creation. Since the particles began at frame 94, they will remain visible throughout our animation.

5.  Save your file as faucet_8.max.

Merging the Faucet with the Rest of the Scene

It’s time to place the faucet animation into the bathroom scene created by the rest of the team. The scene is set up with a camera, lights, and materials ready for our use.

1.  Open bathroom.max from the CD.

2.  Under the File pull-down menu, select Merge. In the browser, choose faucet_8.max—either the file you just created or the version on the CD—and click Open. A Merge dialog box appears, listing the items in the faucet file. Click All and then click OK. The faucet appears in the scene.

3.  Make the Camera view active and render it; it’ll look like Figure 11.33. Save as waterburst_1.max.

FIGURE 11.33  Our faucet, merged into the bathroom scene

Applying Materials to the Faucet

Now we will apply materials to the faucet, using some of the materials assigned to other parts of the scene.

1.  Open waterburst_1.max from the CD or continue working on your scene.

	2. Select the faucet_loft and press M to open the Material Editor. Click the sample sphere that contains the material named Brass. Click the Assign Material to Selection button.
	3. Now we have to create a material for the water. Select an unused sample sphere (the second slot) and click the Get Material button. In the Browse From area of the Material/Map Browser, check Mtl Library. Locate the Ground_Water material from the 3dsmax.mat library; double-click it to place it into the unused sample slot. Close the Material/Map Browser.

4.  Using Select By Name, select the Super Spray object in the scene. Click the Assign Material to Selection button to assign the Ground_Water material to the Super Spray.

5.  Go to frame 100 and render the Camera view, which should look something like Figure 11.34.

FIGURE 11.34  What’s bursting from this faucet?!

Well, it looks a bit more like putty than water. Let’s adjust some parameters in the material to make it appear a bit more realistic.

6.  In the Material Editor, rename the Ground_Water material Water Blob in the field beneath the sample spheres. Under Anisotropic Basic Parameters, click the Ambient color swatch and choose a bright cyan. Watch the sample slot as you change the values. The Ground_Water material should begin to brighten up. (If you would like to use exact RGB values, enter the following values: Red=18, Green=224, and Blue=255.)

7.  Without closing the Color Selector, click the Diffuse color swatch. Choose a sky blue (or enter Red=11, Green=126, and Blue=207). Click the Specular color swatch and set it to pure white (Saturation=0, Value=255). Close the Color Selector.

8. Water is transparent, with the transparency greater in the middle than at the edges. So: Set the Opacity to 25. Click the Background button to turn on a checkered background in order to see the transparency effect. In the Extended Parameters rollout, check In under Falloff for Advanced Transparency and set the Amount to 41. This gives us our decrease in transparency towards the edges. Click the Filter color swatch and choose a very pale sea-green color (or enter Red=200, Green=241, and Blue=238).

	TIP Filter color is great for creating bubbles and glass with many hues, and for casting tinted shadows that vary in density relative to the object’s transparency and filter color.

9.  Go to Frame 98 and render the Camera view, which looks something like Figure 11.35. Save your file as waterburst_2.max.

Synchronizing the Animations

You may have noticed that the bathroom scene contains an animation of the water tap on the right turning on and off. The faucet begins to turn on at frame 10 and is open until frame 35. We will synchronize our water burst with this animation by moving the Displace animation and altering some timing values of the particles.

1.  Open waterburst_2.max or continue working with your current scene.

FIGURE 11.35  That’s more like it!

2. Using Select by Name, select the Displace01. Open the Track View and, in the lower left corner, click the Zoom Selected Object button. The Track View hierarchy should display the Displace01 track. Open its hierarchy to display the keys in its Position track.

3. Let’s move the whole range of animation to a new location. Select the first key. Using the Move Key tool, drag your cursor over the middle of the Position range bar above the keys. Drag the range to begin at frame 35, when the tap is fully open. Watch the time value of the first key change from 0 to 35 as you drag. The Displace effect will now begin at frame 35 and end at frame 135. Close the Track View.

4.  Now we need to adjust the timing of the particle system so that the water comes out of the faucet 35 frames later. Using Select by Name, select the SuperSpray01. In Modify Ø Particle Generation, set Emit Start to 129 and Emit Stop to 130 (35 frames later).

5.  We want the whole animation to be 180 frames. Click the Time Configuration button and set the Length to 180.

6.  In the Modify tab of the particle system, set Display Until to 181 and set Life to 52 to ensure that the particles will remain visible until the end of the animation. Save the file as waterburst_3.max.

© 2000, Frol (selection, edition, publication)