Working with Procedural Textures

Working with procedural textures is just like working with regular textures. You select them the same way, and they can be displayed in the same way. They do take longer to display however (because each pixel is computed instead of loaded from memory).

To define a material with a procedural texture

1. From the Settings menu's Rendering submenu, choose Materials.
   The Material Editor dialog box opens.


2. From the Material menu, choose New.
   If the Palette Tree is not displayed, the New Material dialog box opens. If the Palette Tree is displayed, a new entry appears in the palette. In both cases, focus is on the default material name.


3. Key in a name for the new material (and click OK if entering the name in the New Material dialog box).


4. In the Material Editor dialog box, click on the Pattern map or Bump map icon as required.
   The Open Image File dialog box opens.


5. Use the controls in this dialog box to select the procedural texture file. Procedural textures have the extension “.pma” (procedural MDL application) and are stored in the “...\program\MicroStation\mdlsys\textures” folder.


6. Click the Open button.
   The Map Editor opens with the procedural texture loaded. It appears also in the display area of the Material Editor dialog box.


7. (Optional) To preview the application of the procedural texture to a surface or solid, select Material > Preview Element or click the appropriate icon, in the Material Editor dialog box, than identify and accept the element.


8. Make any adjustments required to the settings.


9. Select Palette > Save (or Save As), or click the Save icon, to save the palette file with the new material.

Editing material definitions with procedural textures

Any of the standard parameters that can be edited for standard textures also can be edited for procedural textures. This is done in the Map Editor dialog box.

In the wood material, for example, various wood patterns can be created simply by changing the size of the material in any combination of the x, y, and z axes. When the size of the wood material definition is changed in this way, the grain still aligns correctly at each edge.

Doubling the value in the Size X field, relative to those for Y and Z, stretches the pattern of the wood grain along the x-axis.

Doubling the value in the Size Y field, relative to those for X and Z, stretches the pattern of the wood grain along the y-axis.

Editing procedural texture values

In addition to the standard parameters, each procedural texture has its own specific parameters that you can edit. For example:

• The sample procedural texture, Wood, has parameters that determine the wood's base color and ring color.

  Procedural Texture Values dialog box for sample Wood procedural texture. Here, as well as the values in the list box, you can change, individually, the wood's Base Color and Ring Color

• The sample procedural texture, Marble, has parameters that determine the appearance of the veins in the marble.

  Procedural Texture Values dialog box for the sample Marble procedural texture. Changing these values alters the appearance of the material in the rendered image.

For this procedural texture, the degree of “Complexity” and the “Vein Tightness” or sharpness of the veins can be altered. Thus, it is possible to produce a range of marble materials, with different colors and vein structure, from the single marble procedural texture.

Simply by changing these two values, you can alter the appearance of this material. This is in addition to the Size X, Y, and Z fields in the Define Materials dialog box.

Changing “Compexity” to 1.0 produces a smoother vein.

Changing “Vein Tightness” to 1.0 produces a sharper, more clearly defined, vein.

To edit a material definition with a procedural texture

1. In the Material Editor dialog box, with the material palette that contains the material open, select the material from the Material option menu.


2. (Optional) To adjust the standard parameters, use the controls in the Material Editor dialog box.


3. Click the Pattern map, or Bump map icon.
   The Map Editor dialog box opens. The title bar indicates the material name.


4. Use the controls in the Map Editor dialog box to adjust procedural texture-specific parameters.


5. From the Material Editor dialog box's Palette menu, choose Save.
   or
   Click the Save Palette icon in the Material Editor dialog box.

Tool tips help

Each procedural texture has tool tip help, which includes information on the parameters, and how they affect the appearance of the material. If you hover the pointer over the settings, a tool tip displays with information on the setting.

Orientation of procedural textures

Procedural textures, by default, are computed relative to the minimum extent of each element, or to the origin of its cell, if any. Where a model is constructed from a number of separate surfaces, then these should be grouped, before applying a procedural texture.

A simple way to do this, is to create a cell of the required surfaces. They will then be processed as a single element.

If left ungrouped, the procedural texture is applied relative to the origin of each surface individually. In other words, there would most likely be mismatches of the texture at any edges.

Where a model consists of a number of separate surfaces, the procedural texture may not match correctly at the edges.

Where a model is a single entity, such as a solid, or a cell, then the procedural texture is applied correctly, and matches along the edges.