| Texture | Cloud | Fractal | Advanced | Render Tree Usage
Shader Type: Texture
Output: Color (RGB) value
Simulates a simple cloud with a roughly spherical topology. Based on a 3D fractal function that can be animated. Because of the method used to determine how close to the cloud’s silhouette we are, it is necessary to use this shader on objects of spherical shape, like spheres or other curved surfaces.
|
Name |
The shader’s name. Enter any name you like, or leave the default. |
|
Texture Space |
Defines the texture space the texture will be applied to. The projection can be defined per object or to all objects in the selection. Object Selection: When multiple objects are selected, defines whether changes are applied to all objects or a specific one. This control updates automatically as you select objects in the scene, as long as the property editor is not locked. Property Selection: Lets you choose a Texture Support. If no texture support has been defined, you can create one by clicking New. If a texture projection is already defined, you can edit it by clicking Edit. Edit: Opens the Texture Support property page for the defined texture projection. New: Defines the new texture projection to be created. You can choose from the following: • UV: Projects the texture along the U and V. • Planar XY: Projects the texture on X and Y coordinates only. • Planar XZ: Projects the texture on X and Z coordinates only. • Planar YZ: Projects the texture on Y and Z coordinates only. • Cylindrical: Projects the texture as though it is a cylinder wrapped around an object. • Spherical: Surrounds the object with a spherical mapping across the whole surface with some distortion. • Spatial: The texture is centered on the scene’s origin. • Cubic: Applies the texture onto the object by first assigning the object’s polygons to faces of a cube, and then projecting the texture onto each face by default. The layout of a cubic projection can be completely customized using the options in the Texture Support property editor. • Camera Projection: The texture is mapped relative to the camera’s center. In this coordinate system, the camera is the center of the “world,” with an up vector, looking toward the negative Z axis. The result resembles an image projected from a camera. The texture will move with the camera and will be affected by any scaling, rotation, and translation. • Unique Uvs (Polymesh): Applies a texture to polygon objects by assigning each polygon’s UV coordinates to its own distinct piece of the texture so that no two polygons’ coordinates overlap each other. • Advanced: Opens the Create Texture Support property page from which you can explicitly define a texture projection. |
Bump Mapping
|
Enable |
Switches bump mapping on or off. |
|
Use Alpha |
Will use the texture’s alpha channel to achieve a bump map. |
|
Factor |
Defines how “bumpy” the bump map will be. A negative value will invert the bump inward and a positive bump map factor will bump outward. |
|
Step |
Controls the U, V, and Z steps of a bump map. Use this parameter to “smooth” bumps or make them more jagged. |
|
Name |
The shader’s name. Enter any name you like, or leave the default. |
|
Clouds |
Defines the color of fractal clouds. |
|
Sky |
Defines the color used for the sky (constant background color). |
|
Include Alpha |
Calculates the alpha channel when rendering. |
|
Contrast |
Controls the contrast of the colors. 0 uses the average of the two colors, and no blending is attempted. This speeds up rendering a little. |
Copy Alpha to RGB
When activated, multiplies the RGB channels with the alpha channel by the factor define in the Alpha Strength parameter.
|
Alpha Strength |
Determines the factor by which the Alpha is multiplied with the RGB channels. |
|
Name |
The shader’s name. Enter any name you like, or leave the default. |
Fractal
|
Noise Type |
You can choose two noise functions to build the fractal: Perlin and Recursive. |
|
Level Decay |
The amplitude of decay of the fractal iterations, defined as the ratio of the amplitudes of two successive iterations. For values less than 1, successive iterations decrease in amplitude; for values greater than 1, they increase in amplitude and the fractal becomes unbounded. |
|
Frequency Multiplier |
The frequency multiplier for subsequent iterations. Fractal frequency is the inverse of scale. Doubling the frequency with the Frequency Multiplier is the same as scaling down the texture by a factor of 0.5. 1 = a sharp fractal texture with low detail; 2 = a more detailed and varying texture. |
|
Complexity |
The maximum number of noise iterations used when calculating the fractal. Works with Minimum Level in determining the complexity of the fractal. |
|
Level Minimum |
The minimum amplitude at which iteration will continue. Used to determine how often the noise function is called. This parameter can be used to control the amount of detail in the texture. |
|
Time |
Defines the time (seconds) used to animate clouds. |
|
Absolute |
When on, the fractal procedure uses a slightly different algorithm, which causes discontinuities in the fractal itself. This creates the impression of turbulence. |
Edge Transparency
Controls the transparency of clouds’ edges and/or centers. Although this creates more realistic clouds, it takes longer to render.
|
Enable |
Switches on the edge transparency parameters. |
|
Range |
Controls the abruptness of the change from the center of the cloud to the edge. If the value is small, the change is abrupt. |
|
Amplitude |
Defines the base amplitude of the fractal used to calculate the edge transparency. This parameter only applies to the amplitude of the first iteration; successive iterations may further increase the amplitude. |
|
Center Threshold |
Defines the average alpha value at the center of the cloud. |
|
Edge Threshold |
The corresponding value for the cloud’s edge (see the above parameter). |
|
Name |
The shader’s name. Enter any name you like, or leave the default. |
Alternate
|
U, V, Z |
Specifies whether every other copy of the repetition should be reversed so that the successive copies of the texture are alternated. |
Repeats
|
Texture Repeats |
Contains the repetition factor in X,Y, and Z. A value of 2, for example, shrinks the texture so that it fits twice in a [0..1] interval. |
UV Remap
|
Minimum, Maximum |
Determines the remapping of the texture image. For a 2D image, only X and Y are used. |
Color parameters can be connected to other textures or image processing shaders. A texture’s scalar parameters can be altered to create interesting effects by applying Texture Generator shaders to them. For example, the Contrast can be controlled with the Gradient Texture Generator shader.
A texture shader has limitless capabilities in a render tree. It can texture an object, be used as a camera or light projection, define bump or displacement maps, or be blended with any number of other textures to create any effect.
Autodesk Softimage v.7.5