In This Tutorial We Are Going to Look at an Interesting Method of Creating the Spray Off

Wake Spray-

In this tutorial we are going to look at an interesting method of creating the spray off a wake from a boat or a buoy in the water.

As this one takes quite a bit of set-up prep work and I wish to focus this tutorial on the creation of the particles I will be providing you a file to start with that contains all the necessary elements used in the creation of this particle system. It can be downloaded here:

http:\\tutorials.diclementi.com/wake_start.max

Inside you will find quite a few things created for you this time. A Sphere to stand in for our buoy, a plane with an animated wave and noise modifier on it to simulate waves in the water. You will find a curved shape in front of the sphere which we will use for our particle emitter, it has been made un-renderable in the object parameters. You will find a Gravity, a Wind, a UDeflector which has been assigned to the water, and you will find a plane diagonally facing up which we will use to set the speed of the splashes and spray.

If you are uncertain as to how I created any of these items I recommend starting with a tutorial aimed more at beginner skills rather than this one.

Once you have opened the file we can jump right into Particle View by hitting 6 on your keyboard or finding Particle View in the Graph Editors menu at the top of your screen.

As always we will first drag and drop an empty flow from the depot list at the bottom of Particle View and place it in the empty light grey stage area. Then select the Title bar of the box that is created for you named PF Source 001 and adjust its settings to the right in the command panel.

This might also be a good time to add a couple of 0's in the Particle Amount upper limit field as well just to make sure you can see all of your particles in the viewport.

Next, drag and drop a Birth operator from the depot to the empty light grey stage area below the PF source 001 box we just created and adjust its settings to the right as well. Remember to connect the blue node from the first box to the empty circle node on top of the second box labeled Event 01.

We want our "buoy" to make splashes and wakes for the entire animation as though it happens all the time, so I started with a negative value so particles are already on the screen before frame 0, and I carried it through to the end of my timeline which should be set to 300 for you already.

I am also starting with 1000 in my amount field, but I know for a fact that this will more than likely be closer to 10,000 once I am finished. I just don't want to cause my computer any unnecessary stress until we are finished!

This is also a great time to select your Display operator and change it to lines and maybe a light blue or white color so you can see the directions of our splashing.

Next, we want to use the silly looking curved object floating in front of our buoy sphere as our emitter, so I will add a Position Object operator between the birth and the Display.

Using the By List button find the object which I have named "Emitter" in your scene.

The shape of this object gives us a starting point for our particles that is slightly wider than our sphere but follows the shape fairly well.

In order to create it I simply copied some of the polygons from my sphere shape around the middle to a new object.

Now, we want our particles to spawn in this shape, but we want them to immediately be coming from the water and not directly from the floating shape above the sphere.

So next we will add a Lock/Bond test operator to the Event 01 box at the end.

This is a very interesting operator that helps us to limit the movement of our particles to or through a surface.

Use the By List button and select the Water object in your scene.

Check the Lock to Surface Radial button, and mark Animated Surface and Snap to Surface.

Then check the Restrict to Surface check box under the Position Lock/Bond settings.

Set the force to 0.0% as we don't want them stuck, just restricted to the surface.

Do the same thing for the force% in the Rotation settings farther down as well.

This will make our particles leap directly from the emitter object to the surface of the water. Next we need to spawn some splashes as our buoy moves forward through the waves.

Add a Spawn operator below the Lock/Bond we just created and adjust its settings to the right in the command panel.

The default of Once is fine, and go ahead and mark the Delete Parent box.

then tell the original particles to spawn 3 offspring before moving into the next Event.

Next, we will define our splashes. Drag and Drop a Speed by Surface operator from the depot to the empty light grey stage area below the Event 001 box, and connect the blue node from the Spawn operator we just made, to the new empty circle node in the Event 002 box we have created.

Set your speed to a number that gives you whatever height you wish your splashes to be, I have chosen 45 with a variation of 8. The higher this number the higher your splashes will be.

Use the By List button to add the "speed controller" plane in the scene. This one is diagonally tilted upwards to send our particles slight forward and up just like a splash would happen in front of a moving boat.

You can increase your Divergence slightly to get a more random look to your splash.

You can also change your display to your liking, I have put mine right back to lines and a light blue color.

Now we will tell the splash to return to the water, as what goes up must certainly come back down again!

Add a Force operator below the Speed by Surface we just created and add both our Gravity and our Wind to the Space Warps list using the By List button.

I recommend taking a closer look at the settings I have made for the Gravity and Wind on your modify tab outside of particle view to get a better idea of how they work.

I am using the Wind for the turbulence only, and the Gravity to pull them gently back to the water's surface.

You can adjust either of these to your liking.

Now we will add a Delete operator below the Force so our particles don't last forever.

We want to give the particles enough life span to find the surface again, but not too long so they continue falling forever and lag our computers to death. Set the By Particle Age delete to a Life Span that works for your splashes.. I have chosen 60 with a variation of 10.

Then add a Rotation to the list below the delete so all our particles aren't heading the same direction.

The Default setting of Random 3D works just fine for us.

Finally when drops of water hit the surface again we want to allow them to bounce back up a bit giving a more realistic secondary splash effect to our particles. So Add a Collision operator to the bottom of the Event 002 box.

Use the By List button to add the UDeflector from the scene to the Deflectors list ... The UDeflector is just set at its default value of 1.0 in the Bounce.

The Default of collides / Bounce works just fine for this one.

Next, we want our splashes to settle back on the top of the water and leave a white foamy bunch of particles in its wake.

So drag and drop a Speed operator from the Depot, to the empty light grey stage area below the Event 002 box. Then connect the blue node from the Collision we just created to the empty circle node in our new Event 003 box.

Set your speed at whatever value gives you the effect you want. I find that 60.0 with a variation of 10 pushes my particles away from the sphere at a distance to my liking.

Set the Dropdown in Direction to Icon Center Out, so the particles don't shoot down, but all around the sphere.

You can give them a bit of divergence to liven things up a little as well, I have chosen 10.

Now we need to make sure these new particles stay on the surface for a bit and trail behind the object. So add a new Lock/Bond operator below the Speed we just created in Event 003.

Use the By List button to add the Water to the Lock On Objects list

Mark Lock to Surface, Animated Surface, and Snap to Surface again like before.

Check the Restrict to Surface box as well.

Set your Force % to 0.0

Try playing with the Drop Down menu here to get some different effects out of your particles. The Dampening field lets you set resistance like Air/Fluids ...

I would set my Resistance and Speed Unit rather slow for this one, unless you want them dead stopped or moving like rockets across the surface of the water ... you may find you don't need these ones, or that you get a good effect by raising them if your object doesn't move a lot in the water.

Set the Force in Rotation to 0.0 as well.

Your particles will now stay on the surface and trail behind the buoy. Now all we have to do is make them vanish after a little bit of time to work like real wake spray.

Add an Age Test operator below the Lock/Bond 002 that we just made.

Set it to whatever length of time you want the wake to exist. I have chosen 120 Life, with a variation of 10. If your buoy doesn't move through the water like a boat, then shortening this might look better, vice a verse for a faster moving boat.

This will check the particles and upon reaching an age of 120 frames give or take 10, the Age Test operator sends them on to the next event through the blue node it came with.

Drag and Drop a Delete operator into the empty light grey stage area below the Event 003 box, and connect the blue node from our Age Test to the empty circle node in our new Event 004 box.

The Default value of All is fine for this one, our Age Test is doing the calculations for us this time.

That's it! You have created a wake splash for your Spheroid buoy! Try manipulating it to fit different objects that sit on the water ... ducks, boats, buoys, shark fins, etc.

Try increasing the original Birth value to 10,000 or so... give or take whatever you like.

Add a Shape to your particles in the PF Source box, I recommend a 3D Tetra very small with perhaps a 35% variation ... then a Material Static and texture the particles to look like what droplets of water similar to what we did in the Splash tutorials.

Turn on Motion Blur so the jagged edges of your shape don't show up in your render, just like we did in the Splash tutorial as well!

If you would like to see a preview animation of this effect in full action you can see a movie clip here:

http:\\animation.diclementi.com/wakespray.mov

I hope you enjoyed this one!

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