sky_base
A sky_base material is used for the sky objects.
States
In the States tab you can set rendering passes and available options. Enabling some of the states activates additional textures and parameters in the Textures and Parameters tabs respectively.
The states divide into 2 groups: Passes and Options.
Possible values for all the other passes:
| GUI name | XML name | Description |
|---|---|---|
| None | none | Material is not rendered during the pass. |
| Default | default | Material is rendered during the pass. |
Possible values for a Background option:
| GUI name | XML name | Description |
|---|---|---|
| None | disabled | A background texture is not used. |
| One texture | single | One background texture is used. |
| Two textures | double | Two background textures are used. |
All the other options can be either enabled or disabled by ticking the respective boxes.
The states available for this kind of materials are listed below.
Passes
Passes specify during which rendering pass the material should be rendered. They are modified in the Passes field of the States tab.
| GUI name | XML name | Description |
|---|---|---|
| Ambient | ambient | Ambient rendering pass. Specifies, how the material should be rendered during the Ambient light pass for the opaque objects. The actual opacity or transparency of the material depends solely on the set blending options. |
| Light world | light_world | World lights rendering pass. Specifies, if the material should be rendered illuminated by the World light sources during the light and shadows rendering passes. |
Options
The following options are set in the Options field of the States tab.
| GUI name | XML name | Description |
|---|---|---|
| Background | background | Enables a cube map texturing of the sky sphere. This option allows to use static sky images, for example, to create a night sky with stars. |
| Clouds | clouds | Specifies if the procedural clouds will be rendered. |
| Soft interaction | volume |
Provides a proper interaction of volumetric clouds with other objects (required if Up sample box is checked). It lessens the clouds color depending on their position relative to the object:
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Textures
Clouds Textures
The following textures create textured sky sphere clouds and are modified in the Clouds field of the Textures tab.
The color of the textured sky sphere is calculated in three steps:
- The upper layer of the clouds, Clouds 01, is computed:
- For the first layer, two texture transformations (Clouds 0 and Clouds 1) are summed.
- Mask 0 is multiplied by the Threshold 01, modulating the strength of masking.
- The mask is subtracted from the textures transformation sum.
- The color intensity of the resulting Clouds 01 layer is computed by multiplying it by the Clouds 01parameter value.
- The lower layer of the clouds, Clouds 23, is computed in the same way:
- For the second layer, two texture transformations (Clouds 2 and Clouds 3) are summed.
- Mask 1is multiplied by the Threshold 23, modulating the strength of masking.
- The mask is subtracted from the textures transformation sum.
- The color intensity of the resulting Clouds 23 layer is computed by multiplying it by the Clouds 23 parameter value.
- The rendered clouds are adjusted by the Sphere value that controls the influence of atmospheric scattering on the clouds.
Additional Textures
These textures are present depending on the Background option selected.
| GUI name | XML name | Description | Channels |
|---|---|---|---|
| Background 0 | background_0 | A cube map for texturing the sky sphere with a static texture | RGBA. |
| Background 1 | background_1 | A second cube map for texturing the sky sphere with a static texture | RGBA. |
Parameters
In the Parameters tab you can set or modify base and additional parameters.
Parameters of different types are set in different ways:
- expression - vector values can be set either in the field near the parameter or in the dialog window opened when double clicking this field
- slider - the value can be set either by smoothly moving the slider of the scroll box or manually in the box near the parameter (if required, the value bigger than maximum one for the slider can be set)
- color - the color can be chosen in the dialog window, activated after double clicking the color field
The parameters available for this kind of materials are listed below.
Transform Parameters
Textures transformation parameters are modified in the Transform field of the Parameters tab.
| GUI name | XML name | Type | Description |
|---|---|---|---|
| Sphere | sphere_transform | expression | Transformation of the sky sphere:
|
| Volume | volume_transform | expression | Transformation of the volumetric clouds mask. |
| Noise | noise_transform | expression | Transformation of the volumetric noise texture. |
| Mask 0 | mask_0_transform | expression | Transformation of the mask texture mask_0. |
| Mask 1 | mask_1_transform | expression | Transformation of the mask texture mask_1. |
| Clouds 0 | clouds_0_transform | expression | First transformation of the cloud texture clouds_01. |
| Clouds 1 | clouds_1_transform | expression | Second transformation of the cloud texture clouds_01. |
| Clouds 2 | clouds_2_transform | expression | First transformation of the cloud texture clouds_23. |
| Clouds 3 | clouds_3_transform | expression | Second transformation of the cloud texture clouds_23. |
Volume Parameters
Volume parameters control the appearance of volumetric clouds. They are modified in the Transform field of the Parameters tab.
| GUI name | XML name | Type | Description |
|---|---|---|---|
| Color 0 | volume_color_0 | color | Volume color of the volumetric clouds |
| Color 1 | volume_color_1 | color | Shadowed volume color of the volumetric clouds |
| Multiplier | slider | volume_01_scale | Color multiplier for the volumetric clouds:
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| Scattering | slider | volume_scattering | Coefficient controlling the influence of atmospheric scattering on the volumetric clouds:
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| Turbulence | slider | volume_turbulence | The size of noise applied to the volumetric clouds:
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Clouds Parameters
Clouds parameters control the appearance of textured sphere clouds. They are modified in the Clouds field of the Parameters tab.
Sphere Parameters
Sphere parameters are modified in the Sphere field of the Parameters tab. Backgroud 0 and Background 1 parameters are present only if Background option is set to One Texture or Two Textures mode respectively.
Soft Interaction Parameters
Interaction parameter is present only if Soft interaction option is enabled and is modified in the Soft interaction field of the Parameters tab.
| GUI name | XML name | Type | Description |
|---|---|---|---|
| Interaction | volume_scale | slider | Depth factor that controls the volumetric clouds dispersal depending on their position relative to the object (see Volumetric interaction description):
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Shadow Parameters
Shadow parameter controls the appearance of shadows from clouds and is modified in the Shadow field of the Parameters tab.
| GUI name | XML name | Type | Description |
|---|---|---|---|
| Multiplier | shadow_scale | slider | Darkness of shadows cast from clouds to the surface beneath:
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