Shader group

The Shader group adds a special effects shading to the mesh. This set of controls creates shading from composition lights set by After Effects or Trapcode Lux. Mir supports up to up to eight Point lights and unlimited Ambient lights. If a Spot light is used, Mir will respond as if it were a Point light.

Using lights. Using the Shading modes requires an After Effects light in the composition to be visible. Once a light has been added, Mir can add special effects shading. The mesh will become illuminated and respond to characteristics of the composition lights.

One way to add color to the Mir mesh is to add colored Point lights of varying intensities to your composition. Mir responds to where the light is positioned in the composition as well, so changing the distance relative to the plane will affect how Mir is lit. Lights of varying colors may be implemented to create multicolored effects.

Shader pop-up

The Shader is an important part of how the polygon mesh is visually rendered and its response to composition lights and the camera. The three Shader options determine how the mesh appears as a textured material, and its response to composition lights. Each Shader option has an optimal combination with certain Material settings and Blend modes, and we suggest those combinations below. Other settings can be used, of course, if a certain look is desired.

There are three Shader options. We describe them briefly here, and in more detail in the next section.

- Flat: Polygon surfaces appear flat. The edges of the polygonal faces appear harder and sharp. They are more ‘step-like’ compared to the more gentle slopes of the other Shader modes.
- Phong: Polygons are rendered as a smooth surface.
- Density: Polygons are rendered with density or a perceived thickness to the material, which creates a thin film-like material that responds to the angle of the composition camera.

NOTE: When enabling Ambient Occlusion, Shader should be set to Phong or Flat, Blend to Off and DepthBuf On.

Shader> Flat mode

Flat gives a flat shading that shows the polygons clearly, and is great for creating abstract backgrounds and geometric design elements. When you set to the Shader to Flat mode, the polygonal faces that make up the Mir planar mesh are accentuated and give a less smooth, more geometric appearance.

Like the Phong mode, you should have the Blend turned Off and DepthBuf to On for best results. You may add some texture to the Flat Shader mode by using the Nudge Color control found in the Material group. Ambient Occlusion may also be used with the Flat mode to add depth and shading. In order to fully see the effects of Phong and Flat shading, at least one Point light should be created in the composition.

Shader> Phong mode

The Phong Shader mode will render the polygonal mesh as a smooth surface.

With the Material controls, you can add reflective highlights and adjust the shadow falloff. This is useful for creating more solid forms that have a smooth, organic feel to them. The Blend mode should be switched Off and the DepthBuf should be switched On for best results.

Shader> Density mode

This mode is good for creating nebula-like and semi-transparent looks.

When the Density shader is enabled, polygons that face the camera head-on become more transparent and polygons that face the camera at an angle become more opaque. The layers of the mesh build on each other to make it more opaque dependent on how many polygons are overlapping in that view. This is similar to how Form works when it uses a lot of particles.

The Super Add mode is useful when there are very bright lights in the scene that cause colors to become gray-ish. When activating the Super Add mode, Mir uses HDR calculations to reveal the real colors in the gray areas. However, activating the Super Add mode sacrifices the alpha channel.

Set Blend to Add or Super Add and set DepthBuf to Off for best results. DepthBuf doesn’t work well with the Density Shader, so it should be off in this mode.

Draw pop-up

The Draw mode decides what kind of primitive is making up the mesh. Draw options create different looks for the mesh.

There are four Draw modes.

- Fill: Default setting. The polygons that make up the mesh render as filled in on all sides.
- Wirefame: Turns the polygons of the mesh into a wireframe skeleton of the plane. In this mode you can use the Line Size controls to increase the width of the lines in the wireframe. Higher numbers will create thicker lines. When changing to Wireframe mode, you may want to change to a reduced Geometry setting.
- Points: Render polygons as a point cloud. This mode is very similar to Trapcode Form, but Mir renders these Points much faster using the GPU. Use the Point Size to increase the size of the points that make up the plane, and adjust how large the points appear.
- Front Fill, Backwire: Creates a mesh that has a Fill texture on its front and a Wireframe Texture on its back side.

Top left to right, Fill mode and Wireframe mode.
Bottom left to right, Point mode and Front Fill mode.

Line Size

Specify the size of lines for the Wireframe mode. Active when Draw> Wireframe or Draw> Front Fill, Backwire is selected. Use the Line Size controls to change the size of the lines in the wireframe in those modes.

Point Size

Specify the size of points for the Points mode. Active when Draw> Points is selected. Use the Point Size control to adjust how large the points appear in Points mode.

Blend pop-up

Blend Mode sets the way the polygons that overlap are blended together.

There are four Blend modes:

- Off: Turns blending off. Generally the Blend mode should be set to Off when using Flat and Phong shading to produce the best results. When Ambient Occlusion is enabled, Blend should be set to Off, since Ambient Occlusion can be seen best that way.
- Normal: Performs regular composite operation. This is of limited use in Mir but provided as a creative option.
- Add: Default setting. Adds polygons to each other so intensity increases as many polygons are overlaid. This mode has the tendency to create white highlights in the lighting scheme where two intense lights overlap each other. Useful with the Density shader.
- Super Add: Renders everything on black background and made to work very well with Density shader. The Super Add mode does not need to be used if the lights are over 100%. If colored lights are turned up to a very high intensity and become super bright, the surface of Mir may start to look gray and washed out. Use the Super Add blend mode to bring these colors back

> NOTE: The Alpha channel of the Mir layer will become disabled when the Blend mode is set to Super Add. This means that the rendered output can display some HDR-like features, even in 8 and 16 bpc modes.

DepthBuf pop-up

Shows which pixels are on the front of the Mir mesh. Doesn’t display the pixels behind the mesh.

- Off: The default mode. This parameter doesn’t work well with the Density Shader, which is the default Shader option, so should be off in that mode.
- On: Checks which pixels are in front and doesn’t show the pixels behind them. When enabling Ambient Occlusion, DepthBuf should be set to On.

Density Affect

One of two Density parameters. When they are turned to 0, the shader becomes graphic and will 'add' onto itself to create bright highlights. When the Density Affect is turned up, it stretches out the fractal, the higher this is turned up, the more transparent the material will be.

Normal Affect

One of two Density parameters. At higher values, the more the material is facing the camera, the more transparent it becomes. This can be used to mimic the way a thin material would behave. Adjusting the Amplitude in combination with this control to create an interesting 'x-ray' look.

Multisample

Sets the number of sample points per pixel and is an anti-aliasing tool. Turn this control up to get rid of jagged edges around the Mir mesh. Keep in mind that the higher the setting, the more memory and render time will be required.

IMPORTANT: Because of the render issue, we highly recommend that you turn multisampling down to a low setting when you first set up the mesh.

NOTE: Different video cards support different levels of multisampling. Mir will only let this be set as high as the card allows it. A most cards can handle it set to 8, but some cards may be able to support 32.

Ambient Occlusion pop-up

Provides shadowing of inset polygons that are obscured by the mesh around it, which is useful to add depth. All modes except Off take the same amount of time to render. When set to Off, there will be no ambient occlusion on the mesh, which reduces VRAM usage and increase render speed.

There are five Ambient modes:

- Off: No Ambient Occlusion. This reduces VRAM usage and increases render speed
- On: Smooth (not noisy) AO, but can contain artifacts. When turned on, AO analyzes how embedded a polygon is in relation to the other polygons around it.
- Dither 1: A dithered AO.
- Dither 2: A dithered AO. This is the most accurate mode of the three Dither settings.
- Dither 3: A dithered AO.

Working with AO controls

There are four Ambient Occlusion (AO) controls, and all work best when kept at lower settings. Some banding artifacts occur at when these settings are turned up on higher levels. You can use the Dither settings under the Ambient Occlusion pop-up to get rid of these bands, but keep in mind some noise effects occur within the Dither modes as well, which may not be desirable. You can also adjust the Ambient control found under the Material group to adjust how the AO responds, as well as combining it with the effects of other composition Point lights.

When using AO, the Shader should be set to Phong or Flat, the Blend mode to Off and DepthBuf On. This shading technique works with the Ambient lights set up in your composition. Adjust the intensity of these lights for different results.

Left to right, Ambient Occlusion is off and on.

AO Intensity

The strength of AO. Turn up the AO Intensity to add strength to the Ambient Occlusion and darken the shaded areas more. Keeping the AO Intensity low can prevent the banding issues while still adding a dimension of depth to the Material, so it should be kept at an absolute minimum to reduce artifacts and noise.

AO Radius

Changing the AO Radius control will affect the size of the AO effect. The higher the value the larger the shadow. The AO Radius is the one exception under these controls and works best when set at a higher number.

AO Lift

Lifts the sampling a little off the surface to reduce self-occlusion and other artifacts. The AO Lift control can be used to brighten the shadows created in the Ambient Occlusion mode. Setting AO Lift all the way down to 0 may create self Occlusion, so this control should be kept at 0.2 or higher to avoid this.

AO Scale

Scales the AO calculation. A higher value reduces the AO effect. AO Scale acts as an inversion AO Intensity, but is generally not needed to adjusted beyond its default setting.