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The Environment panel's toolbar contains the following items:
| Button | Function |
|---|---|
| Undo/Redo | These two drop-down lists hold the history of actions which have been executed in the Environment panel. They are cleared when a new document is opened. |
| Presets List | This drop-down provides a list of environment presets which have been stored previously. To remove a particular preset, click the red X next to its name in the list. |
| Add Preset | Click this button to store the current settings as a new environment preset. |
| Load .SKY File | Click this button to load a Maxwell .SKY file from your file system. |
| Save .SKY File | Click this button to save the current environment as a Maxwell .SKY file. |
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Following is a summary of what effects the various parameters contained in this panel have on the rendered environment. For a more detailed discussion of these parameters, see Physical Sky.
| Parameter | Description | |
|---|---|---|
| Intensity | This is used to artificially increase or decrease the brightness of the physical sky. | |
| Planet Reflectance | This controls the percentage of light reflected from the planet surface back into the atmosphere. | |
| Ozone | This defines the amount of ozone gas in the atmosphere, measured in the centimeter-height of a column of atmosphere. The default value is 0.04. | |
| Water | This defines the amount of water vapor in the atmosphere. It is measured in centimeters, in the same way as ozone. | |
| Turbidity Coefficient | This defines the concentration of particles in the atmosphere. A value of 0.0 means a perfectly clear sky (in which case the next three parameters won’t have any effect). 0.01 is a good value for low turbidity, e.g. a sky containing very few aerosols, which will appear almost clear. 0.04 is a good medium value and 0.3 is a fairly high value: Raising the turbidity coefficient in sunset situations will darken the sky. By lowering the camera's EV, it is possible to create an interesting sky. | |
| Wavelength Exponent | This defines the average size of the particles in the atmosphere. The particle size influences which wavelengths of light are absorbed and which are scattered. Higher values than the default will increase the saturation of the sky, until gradually it turns first green and then orange. | |
| Reflectance | This refers to the albedo of the aerosols, or the rate of energy scattered and absorbed by the aerosols. | |
| Scattering Asymmetry | This controls the anisotropy of atmospheric particles; that is, in which direction most of the light will be scattered. Positive values will produce a halo effect around the sun, brightening the area around it. |
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When the Image Based environment type is selected, environmental lighting in Maxwell will be provided by the specified HDR image, which will be mapped onto a virtual dome which encompasses the scene.
By default, Image Based environment in the plugin uses its Use Background for all mode. In this mode, the settings specified in the Background Channel panel will be applied to all four of Maxwell's Image Based channels: Background, Illumination, Reflection, and Refraction. If it is necessary to use different HDR images and/or settings in one or more of these channels, simply switch the Mode to Use Separate Channels.
It will now be possible to enter different HDRI, Scale, Offset, and Intensity values for each Image Based channel. Any channel that remains disabled when the scene is rendered will use whichever environment type is specified in the Disabled parameter. While each channel has its own Intensity value, there is also a global Intensity modifier value, which affects all channels together. When Interpolate is enabled, a bicubic interpolation will be applied to the pixels of assigned HDR images; this can be useful when the images being used are of a resolution low enough for pixelation to be visible in the image.
Each channel has a drop-down which allows for setting the source for that channel. Possible channel sources are:
| Source | Function |
|---|---|
| HDRI | The channel uses an HDR image file. |
| Active Sky | The channel uses the sky type specified in the Active Sky drop-down. |
| Background | The channel uses the same values as those defined for the Background channel. |
| Disabled | The channel is completely disabled. |
Each also has Scale, Offset, and Intensity values. Scale and Offset allow the image to be stretched and translated along the U an V axes, while Intensity increases or decreases the brightness of the image. Additionally, the Background channel has a Screen Map mode, in which the HDRI is mapped flat against the image plane, rather than being projected from a sphere encompassing the scene.
As a convenience, it is possible at any time to Copy all parameters from one channel to the others.
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