User manual DIGITAL ANARCHY PSUNAMI

PSUNAMI WHAT IS PSUNAMI? Digital Anarchy Psunami is a plug-in for Adobe After Effects 4.0 or later, which simulates photorealistic oceans and skies. Psunami creates the illusion of real water and air by modeling the true physics of large-body water and atmospheric systems. This is accomplished by creating a genuine 3D environment within After Effects, with polygonal modeling, geometric displacement mapping, a 3D animatable camera, animatable light sources, and raytracing with reflections and texture mapping. Within this environment, you can fully animate the camera in three dimensions, precisely control waves and swells in the ocean surface, simulate haze and rainbows in the atmosphere, and animate two "suns" at once, for fine lighting control. Up to three still or animated image maps can be used to create your own skies, or to incorporate logos in the ocean surface with displacement mapping. 1 WHAT IS PSUNAMI? PSUNAMI Raytracing, the rendering technique Psunami uses to achieve its photorealistic results, is available in most of the professional 3D applications used for special effects production today. When a scene is rendered with raytracing, the computer shoots out virtual light rays from the camera's viewpoint, and traces the bends and bounces of these light rays around the scene back to the camera. If a light ray is visible to the camera, the surfaces illuminated by the ray are rendered in the final view. The renderer takes into account whether surfaces are reflective, translucent, or transparent, and alters the ray accordingly. If enough rays are sent out into the scene (potentially millions), the results can be highly realistic. Shadows, reflections, and refractions (the bending of the light ray through transparent surfaces) are calculated automatically as part of the scene, greatly increasing the realism. Raytracing is especially suitable for calculating objects and scenes with lots of reflective surfaces, like glass and water. As you might guess, calculating millions of rays can be a time-consuming process, and requires substantial computer horsepower to render frames in a reasonable time. Digital Anarchy Psunami has been specially optimized for speed in the After Effects environment, making it one of the fastest 3D raytracers available today. 2 PSUNAMI PSUNAMI PROPERTIES Parameters ­ or "properties", as they are referred to in Psunami ­ are organized into logical groups: RENDER OPTIONS, AIR OPTICS, and so on. You can open each group with the roll-down arrow next to the group name to access the category's properties, or collapse each group to free up screen space and reduce clutter. When you first apply Psunami to a layer in After Effects, the default property settings are used, in which the camera is positioned at an elevation of 10 meters over the ocean surface, facing east toward the sun, and angled down toward the water slightly. As with all After Effects plug-ins, you can return to these default settings at any time by clicking the Reset button next to the plug-in's name in the Effect Controls window. 3 PRESETS PSUNAMI PSUNAMI'S ABOUT BOX If you click the "About..." button next to the Reset button at the top of Psunami's Effect Controls window, the About box will open. In addition to the lovely underwater animation displayed in the About box, you can view Psunami's production credits, visit the Digital Anarchy web site by clicking on the Digital Anarchy logo, and also --this is the best part -- check out how long the last frame took to render. Psunami keeps track of your render times for each frame and displays the time for the last one in the Last Frame Render Time field. You can use this as a way to estimate how long any given Psunami animation will take to render by multiplying the Last Frame Render Time by the number of frames in your animation. Click anywhere in the About box to close it. PRESETS Psunami ships with a number of presets you can use as starting points for your own experimentation. When you first install Psunami, it creates a folder in the After Effects plug-ins folder called Atomic Presets. In that folder is a Psunami folder, and in the Psunami folder you'll find subfolders of preset categories, containing the actual presets. Your own presets and categories will be saved here as well. Be careful not to move or rename these folders, or you may not be able to load your presets. The first property group you will see is PRESETS. If the PRESETS roll-down arrow is not already down, click it to reveal the Presets control panel. The Presets Control Panel The Presets control panel lets you open and apply Psunami presets or collections of property settings; choose which properties will be affected when you apply a preset; organize your presets into categories; save, rename, and delete presets and categories; and reset selected groups of properties to the default settings without resetting all of them. 4 PSUNAMI PRESETS Note that the Presets control panel is divided into 3 panes: LOAD, SAVE, and RESET. You use the controls in the LOAD pane to load and apply presets, and to choose whether to apply all the property groups in the preset, or to apply selected groups of properties. To choose a preset, click on the Preset pop-up menu. You'll see a list of preset categories with sidearrows; drag down to a category to open the side-arrow submenu, then drag over to a preset to select it. To apply all the properties in the preset to your Psunami layer, choose All from the Property pop-up menu, then click the "Go!" button. Important: Your preset will not be applied until you click "Go!". To apply a single property group to your Psunami layer, leaving all other properties at their current settings, choose the desired property group from the Property pop-up, then click "Go!". You can choose other property groups to apply by simply selecting the groups and clicking "Go!" after each selection. The Preset Manager Once you've created your own Psunami settings that you'd like to save for later use, you use the Presets control panel to save and organize them. The SAVE pane in the Presets control panel lets you open the Anarchy Preset Manager, where you can save, copy, rename, and delete your own presets, as well as create, save, and delete your own categories. You can also use the Anarchy Preset Manager to rename and delete the default installed presets and categories, if you wish. 5 PRESETS PSUNAMI To open the Atomic Preset Manager, click on the "Options..." button in the SAVE pane of the Presets control panel. You'll notice three panes in the Anarchy Preset Manager window ­ Save Preset, Manage Categories, and Manage Presets. To save your preset, type a name for the preset, up to 31 characters long, into the Preset Name field, then choose a category into which to save the preset. To choose an existing category, select the category from the "...Into Category" pop-up menu. To save the preset into the existing category you just chose, click the Save button in the Save Preset pane. To create a new category, type the category name, up to 31 characters long, into the New Category field in the Manage Categories pane, then click the corresponding Save button. To save your preset into the new category you just created, select the new category from the "...Into Category" pop-up menu, then click the corresponding Save button. You can also use the Anarchy Preset Manager to copy, rename, and erase presets, and to erase categories. To erase new or existing categories, choose the category from the Erase Category pop-up in the Manage Categories pane, then click the corresponding Erase button. You'll get a warning that erasing a category also erases all the presets in the category. Think carefully before you click OK, because this operation is not undo-able. To erase a preset, select the preset in the Choose Preset pop-up menu, then click the Erase button in the Manage Presets pane. To copy a preset, select the preset in the Choose Preset pop-up menu, then click the Copy button. The preset will be duplicated into the same category where the original is located, with the default name PresetName1. To rename a preset, select the preset in the Choose Preset pop-up menu, then click the Rename button. You'll see a field pop up where you can type the new preset name. Click Save to change the preset name, or Cancel to cancel the name change. To exit the Anarchy Preset Manager and return to the Psunami Effect Controls window, click Done. Resetting Selected Properties The Presets control panel also lets you selectively reset Psunami property groups to their default settings. Once you've loaded a complete preset or one or more property groups from a preset, you may find it necessary to reset one or more of the altered property groups, especially if you're just trying out presets and don't like the results of a selected preset property group you've just loaded. You can always use the standard After Effects "Reset" button found in all Effect Controls windows, but this resets all properties in the effect to their default settings, which will wipe out other property group settings you may want to keep. The RESET pane lets you select individual property groups to reset. To reset a property group, select it from the Property pop-up menu in the RESET pane. All the properties in the property group will immediately be reset to their default values. Important: resetting a property group is undo-able. 6 PSUNAMI RENDER OPTIONS RENDER OPTIONS Psunami's RENDER OPTIONS control how the plug-in will display and render your scene. The RENDER OPTIONS let you render just the air, just the water, or both in your scene; display and render the final output version of your scene in two different qualities, or display a variety of grayscale and wireframe setup modes, grayscale depth maps, or light tracking dots for use with other plug-ins; control the amount of geometry Psunami generates; stretch or loop the animation time; and control the gamma and color scaling in your scene. Render What RENDER WHAT specifies which parts of your scene will be rendered and which will be replaced by a black (transparent) alpha channel. Both Air and Water Selecting Both Air and Water tells Psunami to fully render all the elements in your scene and keep the alpha channel fully white (opaque). The illustration below shows the results of RENDER WHAT set to Both Air and Water with the Psunami default settings ­ a normal render. 7 RENDER OPTIONS PSUNAMI Air Only Air Only renders only the atmosphere and light sources into the scene, with the water area replaced by black in the alpha channel (below left). This allows you to composite your own water or other imagery into the Psunami scene while using the sky generated by the plug-in. Water Only Water Only renders only the water in your scene, replacing the sky with black in the alpha channel (below right). Use the Water Only setting to composite your own skies into your Psunami scene. Air Only and Water Only are also useful for isolating the air and water for individual post processing. In other words, if you want to change the sky color or add a glow to the water, you can render two passes of your Psunami scene, one set to Air Only and the other set to Water Only, then composite both together into the scene as separate layers. You can then apply filters to each layer to affect the water and air separately. Water Only to Max Distance Finally, Water Only to Max Distance renders only the water, just as in the Water Only option, but in this case the water is rendered only to the maximum distance, as shown in the top left illustration on the following page. You set the maximum distance with the MAX DISTANCE slider. 8 PSUNAMI RENDER OPTIONS One use for Water Only to Max Distance is to allow you to composite your own layer into the water in a Psunami scene. To do this, duplicate your Psunami layer, and call it "Max Distance Layer" or something similar. Set this layer's RENDER WHAT option to Water Only to Max Distance, and set the MAX DISTANCE value very low. If you're using the default Psunami values, a MAX DISTANCE setting of 0.1 or less is a good starting point. Position the Max Distance Layer above the original Psunami layer, and composite your own layer between the Psunami layers. Your layer will appear in the midground, with the foreground water from the Max Distance Layer matching the background water in the original layer (top right). Water Only to Max Distance is also useful for eliminating the bright line you sometimes see at the horizon when rendering using Water Only, as in the Water Only illustration on the preceding page. With Psunami's default settings, using Water Only to Max Distance cuts off the extreme far range of the water layer, removing the bright horizon line, as seen below. Note that Psunami's RENDER WHAT options apply only to Wireframe, Texture, Realistic, Too Realistic, and Depth Map RENDER MODES. They have no effect when you're in the Grayscale and Light Tracking modes. 9 RENDER OPTIONS PSUNAMI Render Mode The RENDER MODE settings control how your Psunami scene will be displayed and rendered. Some RENDER MODES are intended to be used only as setup aids, while others are used to generate source layers for additional effects like depth of field blurs and lens flare tracking. Normally, you'll use the Grayscale (Icons) and Grayscale (No Icons) modes to set up your camera and image map positions and keyframes, and to test parameter changes in waves and swells. Wireframe mode is used for quickly previewing your camera and water motion and displacement maps, while the Texture (No Geometry) mode is useful for testing lighting, coloration, and image map placement. You use Light Tracking mode to create tracking images for lens flares and light source replacement, and Depth Map mode to generate grayscale depth maps for depth of field and other z-buffer effects. Finally, Realistic and Too Realistic modes are what you'll use to actually render your final image or animation, with Too Realistic, the slowest RENDER MODE, normally reserved for underwater scenes. Grayscale (Icons) Grayscale (Icons) tells Psunami to display an overhead view of the grayscale image map it uses to generate the water in your scene and to display representations of your camera and image map positions, as shown on the following page with Psunami's default settings. Psunami works by generating 3D geometry from the same data set that is used to generate this grayscale image. Psunami calculates data representing the surface of the water, and then generates a single polygon, or flat 3D object, for each bit of data. Polygons are the fundamental building blocks of 3D geometry. These polygons are attached edge to edge and laid down in a flat grid called a polygonal mesh. Then each polygon is displaced upward in 3D space away from the mesh, coinciding with the lightness of the grayscale pixels--the lighter the pixel, the higher the displacement. The edges of the polygons remain attached to each other, so the effect is like a flat rubber surface pushing upward or rolling downward. As you animate the water, which Psunami does through its PRIMARY WAVES and SWELLS controls, the polygons move up and down, deforming the mesh surface accordingly. When the correct lighting and reflection properties are added by Psunami's raytracing engine, the result is a realistic simulation of a water surface. Since Grayscale (Icons) is a direct representation of the pixels used to generate your water geometry, you can think of this as a top-down view of your ocean scene. You can also see your camera from overhead, represented by a red square with two lines extending from it, and a large trapezoid, as seen in the top left illustration on the following page. The red dot is the camera head, and the trapezoid is the camera's field of view ­ the ocean area you see in Wireframe, Texture, Realistic, Too Realistic, and Depth Map RENDER MODES. 10 PSUNAMI RENDER OPTIONS You can change the camera's position with the camera's X EAST-WEST and Y NORTH-SOUTH controls, and the camera icon will update its position in the Grayscale window--left and right for changes in x, and up and down for changes in y. North is at the top, and East is to the right. Changes in elevation will be noticeable as a change in the "short" side of the trapezoid--try it out to see. Grayscale (Icons) mode renders quickly, so you can use it to preview the motion in camera animations. Grayscale (Icons) mode will also display any image maps you've added to your scene (top right). Displacement maps display as blue frames with a grayscale thumbnail of the image (the grayscale also represents the amount of displacement); Texture maps display as an empty green frame; Displace + Texture maps display as yellow frames with a grayscale thumbnail of the image map. While you can't directly position image maps or the camera in the Grayscale (Icons) RENDER MODE view, you can see and render position changes you make with the IMAGE MAP and CAMERA position controls. Grayscale (No Icons) Grayscale (No Icons) displays the same grayscale image as Grayscale (Icons), but without the camera and image map icons, as the top left illustration on the following page shows. Grayscale (No Icons) was designed for you to render just the grayscale image or movie for use as a displacement map with After Effects' Displacement plug-in or with another 2D or 3D application. If you have image maps applied as displacement maps, you will also see those images without their color frames in the Grayscale (No Icons) view. Otherwise it's identical to the Grayscale (Icons) RENDER MODE. Tip: Use the COLOR MIN SCALE and COLOR MAX SCALE controls to fine-tune a grayscale render. 11 RENDER OPTIONS PSUNAMI Wireframe Wireframe RENDER MODE displays the ocean geometry as only the outlines of the polygons which form the mesh grid used to create the ocean surface (However, be aware that the polygons in this mode do not scale with the actual polygons that make up the mesh). LIGHT, AIR OPTICS, and OCEAN OPTICS settings are all ignored, along with image maps used as textures. The polygons are rendered as aliased white outlines against a black background (top right). Note that Wireframe mode also renders lights as single white dots so you can check light position changes, and adds a series of white dots on the horizon line (the wireframe itself does not extend to the horizon). You can use these horizon dots as references for motion tracking in After Effects or elsewhere. For example, you can motion track these dots in After Effects and derive the position and rotation of a bobbing camera in Psunami, then apply the track data to another layer so it can appear to be part of the Psunami scene. If you do use Wireframe RENDER MODE for motion tracking in After Effects, you'll get the best results if you choose a dot at one end of the horizon for position tracking, and another dot on the opposite end of the horizon for rotation tracking. Wireframe's main purpose is to give you a reasonably fast way to see a camera animation, or to preview how changes in PRIMARY WAVES and SWELLS will affect the geometry mesh. Wireframe gives you an accurate representation of the true position of the camera in relation to the moving waves, which is essential when you're animating the camera close to the surface. Because Wireframe mode isn't raytraced, but only drawn in aliased lines, it's much faster to render than the only other RENDER MODES which show you true geometry, Realistic and Too Realistic, so it's much easier to tell if your camera accidentally goes underwater, for example. 12 PSUNAMI RENDER OPTIONS Texture (No Geometry) Texture (No Geometry) is Psunami's default RENDER MODE, and the one you see when you first apply the plug-in, as shown in the illustration on page 7. In a 3D environment like Psunami's, the program has to keep track of each and every one of the potentially thousands of polygons in a typical scene, texturing and reflecting rays from the surface of each polygon as the settings in the scene dictate. This is where much of Psunami's processing overhead takes place, and is a significant contributor to longer render times. Texture (No Geometry) RENDER MODE is designed to let you set up camera motion, light positions and settings, water coloration, and image maps without the overhead of manipulating all those polygons. In Texture (No Geometry) RENDER MODE, Psunami renders the ocean surface as a single flat plane, and then applies wave and ripple information as a bump map. Bump mapping is a common 3D rendering technique that uses the grayscale values in an image to shade the surface of an object during rendering, simulating the highlights and shadows that would be created by real geometry intersecting the light rays in the scene. In other words, the pixels in the rendered surface are shaded lighter or darker according to the light or dark pixels in the bump map, creating the illusion of a threedimensional surface. Image maps used as displacement sources will also contribute to the bump map shading, letting you test the positioning of displacement maps in the scene -- althought the effect is subtle. Since Psunami doesn't have to process the polygons, Texture (No Geometry) RENDER MODE renders significantly faster than the Realistic modes. One disadvantage of Texture (No Geometry) RENDER MODE is, of course, that it doesn't render true geometry. What looks like a three-dimensional surface is only a render illusion created by the shading. As a result, the ocean surface remains perfectly flat, even when you've placed the camera right above the water (below). 13 RENDER OPTIONS PSUNAMI What this means is that if you're animating an ocean flyover and you want to get down close to the water, don't assume that if the camera appears to stay above water in Texture (No Geometry) mode, it will also be above the water in the Realistic modes. In fact, using the same settings that produced the image on the preceding page, setting RENDER MODE to Realistic produced the image below. The image is mostly black, because the camera is actually below the water. In this case, you would have to go back into your CAMERA settings and adjust the camera position to keep it above the water surface (unless you want the camera to go underwater, that is.) So, feel free to use Texture (No Geometry) to setup your lighting and texturing, but be sure to test camera positions and animations in Realistic or Wireframe modes before your final render. Light Tracking Light Tracking renders only the positions of LIGHT 1 and LIGHT 2 in your Psunami scene, ignoring all the other elements in the scene. Lights render as small white circles identically in the RGB and alpha channels, as shown in the illustration below. 14 PSUNAMI RENDER OPTIONS Light Tracking is intended to be used with Puffin Design's Knoll Lens Flare Pro to automatically apply a flare effect to the sun. LENS FLARE RECIPE: To use Light Tracking mode with Lens Flare Pro, set the parameters in your Psunami layer to your liking, then duplicate the layer. You should only enable one light source when using Light Tracking mode with Lens Flare Pro; if you enable both light sources, Lens Flare Pro will average the position of the two light dots and place a single flare equidistant between them. Set the second layer's RENDER MODE to Light Tracking, and precompose this layer, choosing the option to move all attributes into the new composition. You must precompose the layer before Lens Flare Pro can use it as a tracking source. Name the layer "Light Track Source" or something similar, and turn off its video by clicking on the layer's eye button. Apply Lens Flare Pro to the first layer, and set the Location Layer to the Light Track Source precomp. Lens Flare Pro will automatically track the white point in the Light Track layer's alpha channel, so your lens flare will follow the sun as it moves across the sky. Just remember to update the settings in both layers if you want to change your animation properties. Realistic Realistic RENDER MODE is the setting you'll normally use for rendering your final Psunami scene. Realistic mode renders the full ocean geometry based on your property settings, so that your ocean surface is realistically displaced upward in true 3D space (below left). As mentioned in the section above on Texture (No Geometry) RENDER MODE, placing the camera near the water surface in Realistic mode lets you see correct surface displacement in 3D space, even at the horizon line (below right). Realistic RENDER MODE also enables Psunami's full physics-based render engine, with optically accurate atmospheric imaging, haze, and rainbows. For more about atmospheric settings, see the section on AIR OPTICS. 15 RENDER OPTIONS PSUNAMI Too Realistic (RTM) Too Realistic (RTM) (RTM stands for Read The Manual, by the way) is Psunami's most precise and realistic RENDER MODE, and its most render-intensive. The illustration below shows a frame rendered in Too Realistic RENDER MODE with the default settings. One thing you'll immediately notice is that this Too Realistic image is considerably darker than the Realistic image with the same default settings shown on page 15. You can adjust this, if you want, with the GAMMA SCALE property in the RENDER OPTIONS, discussed in greater detail below. A GAMMA SCALE setting of 0.65 or so should compensate for Too Realistic mode's darker renders. Realistic RENDER MODE'S image quality is good enough for most situations. However, sometimes you need the greater render precision of Too Realistic mode, especially when you place the camera underwater looking up towards the surface. The illustration below left shows an underwater scene rendered in Realistic mode. This scene uses Psunami's default settings, with the exception of the camera, which is placed at an elevation of ­20 meters (that is, 20 meters below the water surface), looking up at an angle of 45°. The image is nice and smooth but not particularly realistic. The illustration below right shows the same image with the same settings, but in Too Realistic RENDER MODE. 16 PSUNAMI RENDER OPTIONS The shading and contrast in the image look more realistic, but you'll also notice a good deal of aliased artifacting in the image at the edges of the lighter areas. This is the Read The Manual part ­ you must increase the resolution of the ocean surface mesh to get photorealistic imagery in Too Realistic RENDER MODE. We'll go into more detail about this in the section on PRIMARY WAVES, but for now all you need to know is that you increase the resolution or fineness of the ocean mesh with the FINE GRID SIZE control in the PRIMARY WAVES property group. To increase the resolution of the mesh, set the FINE GRID SIZE to a lower value, which decreases the spacing between the polygons in the mesh, thereby increasing the overall number of polygons. The illustration below shows an image rendered with the same settings as the bottom right illustration on the preceding page, except with a FINE GRID SIZE of 0.2 (the value used in the bottom right illustration on the preceding page is 0.4, the default). You now see a much more realistic ocean surface with finer detail and smoother edges in high contrast areas. You can increase the mesh detail even further to increase the smoothness of the final render, but be aware that you're also increasing the number of polygons Psunami has to process, which will increase your render times significantly. That's why this mode is called Too Realistic ­ we feel that many Psunami users will find that the increased realism in the final image won't be worth the extra render time. You'll have to decide that for yourself. 17 RENDER OPTIONS PSUNAMI Depth Map Depth Map RENDER MODE lets you render your scene as a grayscale depth map, also known as a "z-buffer image". As the illustation below indicates, areas near the camera are rendered darker than areas farther away from the camera. In other words, the closer a wave is to the camera, the darker it will render in the Depth Map image. By itself, this isn't all that useful, but Depth Map mode's real purpose is to create source layers for specialized effects processing of your Psunami images. One use of depth maps is as a source for After Effects' Compound Blur filter, to simulate a film camera's depth of field defocusing. The Compound Blur effect blurs images based on the grayscale values of a source layer, with darker areas in the source layer causing less blur in the final image than lighter areas. You can use the grayscale values in the Depth Map image to progressively blur a Psunami image, so that areas of the image farther from the camera are blurrier or less in focus than areas closer to the camera. To use Depth Map mode with After Effects' Compound Blur filter, set the wave parameters in your Psunami layer as desired, then duplicate the layer. Name the layer "Depth Map Source" or something else appropriate. Set the Depth Map layer's RENDER MODE to Depth Map, and adjust the COLOR MIN SCALE and COLOR MAX SCALE sliders. You'll find these sliders at the end of the RENDER OPTIONS property group. We'll discuss COLOR MIN AND MAX SCALE in more detail below, but normally they're used to adjust the saturation and contrast ranges of the colors in your Psunami scene. In Depth Map RENDER MODE, however, you use the COLOR MIN AND MAX SCALE sliders to set the range, in meters, within which the Depth Map will render its grayscale values. In other words, COLOR MIN SCALE sets the distance from the camera where the Depth Map image will begin to transition from black to gray. Areas between the COLOR MIN SCALE and COLOR MAX SCALE values will render progressively through 256 shades of gray, from black to white. Areas "outside" of the COLOR MIN SCALE value will render black, and areas "outside" of the COLOR MAX SCALE values will render white. 18 PSUNAMI RENDER OPTIONS COMPOUND BLUR RECIPE: If you're using Psunami's default values, a COLOR MIN SCALE of 20 and a COLOR MAX SCALE of 100 are good starting points. Then precompose the Depth Map Source layer, choosing the option to move all attributes into the new composition. You must precompose the layer before Compound Blur can use it as a blur source. Turn off the video for the precomp layer. Apply Compound Blur to the original layer, and set the Blur Layer to the Depth Map Source precomp. Set the MAXIMUM BLUR to a relatively low value like 2 for best results. You should see a reasonably convincing depth of field blur (below left). Just remember to update the settings in both layers if you want to change your animation parameters. You can also use Psunami's Depth Map RENDER MODE to help you composite your own layers into the Psunami scene. As mentioned above, you can set RENDER WHAT to Water Only to Max Distance in order to composite another layer into the Psunami ocean by rendering two layers, one in Air and Water mode and the other in Water Only to Max Distance mode. You then use the alpha channel in the Water Only to Max Distance layer to mask the Air and Water layer, then insert your own layer in between the two Psunami layers. This technique is reasonably fast and easy to use, but isn't very flexible, especially when you're trying to control the edge of the foreground layer for a smoother composite. It also requires two different Psunami layers with different settings, which makes it that much slower to work with. COMPOSITING RECIPE: The Depth Map compositing technique is a little more complicated, but much more flexible, and only requires one full Psunami layer. This is how it works. First, set up your Psunami scene to your liking. You can work with unrendered layers and precomps if you choose, of course, but as long as you don't need to change your original Psunami layer, you'll find it much faster to work with this technique if you prerender the Psunami layer in Realistic mode as a lossless movie and import it into its own comp. Using the same basic Psunami settings, render another version of the Psunami scene in Depth Map mode as a lossless movie. If you're using Psunami's default settings, COLOR MIN/MAX SCALE values of 20 and 40 are a good starting point. Your Depth Map image should look something like the illustration above right. 19 RENDER OPTIONS PSUNAMI COMPOSITING RECIPE (cont.): If you haven't made a new comp yet, do so, and drag in your Realistic Psunami movie and the Depth Map movie. Duplicate the Realistic layer, and arrange the layers so that the Depth Map movie is on top. Select the Depth Map movie and apply After Effects' Threshold filter, which you'll find in the Adjust submenu in the Effect menu. The Threshold filter takes grayscale images and turns them into high contrast black-and-white images, based on the Level property in the Threshold filter. Grayscale pixels with values above the threshold level will be set to white; pixels below the threshold level will be set to black. Try a Level setting of about 85, which will give you an image something like the illustration below left. We're going to use this image as a Luma Track matte to mask the foreground layer over the background layer. To do this, first make sure the Depth Map layer is directly above the foreground Realistic layer in the Timeline. Switch the Timeline controls from Switches to Modes, and choose Luma Inverted Matte from the Track Matte pop-up for the foreground Realistic layer. This will switch off the video for the Depth Map layer, and mask the foreground layer in the shape of the Depth Map black and white area. By applying the track matte in Luma Inverted Matte mode, we tell After Effects to use the grayscale values in the Depth Map for masking, and to invert the Depth Map so that the foreground is opaque and the background transparent. You won't see a change at this point, since we're masking a layer onto itself. Next, bring your midground layer into your composition, and place it between the foreground and background Realistic layers. You should see the foreground layer intersecting the midground layer, with the background layer behind the midground layer, as in the illustration below right. 20