Texture Object

description

Controls how a Bitmap object is applied to polygons, ParticleBursts, ImageLayers, and any other K-3D objects that utilize Bitmap objects.

creator: Shead Data Processing
version: 1.00
interface:

texture_ui1.gif (2747 bytes)

Bitmaps: Used to select an existing Bitmap object for use by this Texture, or create a new Bitmap object.

Left / Right / Top / Bottom: Controls left, right, top, and bottom indexes into the selected Bitmap, respectively.

texture_ui2.gif (2330 bytes)

Use alpha channel: This Texture will use the selected Bitmap’s alpha channel to control the underlying polygon’s transparency, if Transparency is enabled for rendering.

Use luma only:

Use full-size bitmap: If you are using a large (greater than 256 x 256) bitmap and your system doesn’t have a lot of RAM, turning this option on can speed up rendering (but decreases the quality of the texture).

Perspective Projection: When enabled, textures render properly when their polygons are turned "edge-on" to the Camera. Can be disabled for Textures being used by LensFlares, ImageLayers, ParticleBursts, etc. for an increase in rendering speed.

Texture antialiasing: Toggles texture antialiasing.

restrictions: None.
use:

Create a new Texture object by double clicking on "Texture" in the Object Toolbox, or by selecting the "--- new Texture ---" item in the "Texture" pulldown in a ParticleBurst, ImageLayer, or other object. The Texture dialog will open. Under most circumstances, the first action you’ll want to perform is to select a Bitmap object for use by this Texture. Go to the "Bitmaps" tab in the Texture dialog, and, in the Bitmap pulldown, either select the name of an existing Bitmap object, or select "--- new Bitmap ---", which will create a new Bitmap.

Once you have selected a Bitmap for use with this Texture, you can use the X1 / X2 / Y1 / Y2 indices to control how much of the Bitmap will be used. They represent percentages of the total width and height of the Bitmap, i.e. 0.0 represents the left or top edge of the Bitmap, and 1.0 represents the right or bottom edge. A value of 0.5 would represent the center of the Bitmap. The default values for X1, X2, Y1, and Y2 select the entire bitmap, as shown graphically below:

texture_sample1.gif (4444 bytes)

If you wanted to use just the upper-left-hand quadrant of a Bitmap, you would use values of 0.5 for X2 and Y2, and leave X1 and Y1 at 0.0, as below:

texture_sample2.gif (5485 bytes)

Finally, you can use values for X1, Y1, X2, and Y2 that are outside the range 0.0 - 1.0, enabling you to tile the Bitmap. For example, values of 0.0 for X1 and Y1, and values of 2.0 for X2 and Y2 would create 4 copies of the Bitmap, tiled in the following fashion:

texture_sample3.gif (4673 bytes)

Also consider that you can use negative values for any of the indices, and that you can "flip-flop" the indices to mirror a Texture. Since all of the indices are ControlChannels, you can animate them over time to create zoom and pan effects with the Texture. Finally, you can use the Tile / Clamp Horizontal and Tile / Clamp Vertical controls to select the behavior of a tiled Bitmap. By default, Tile Horizontal and Tile Vertical are selected, causing indices outside the range 0.0 - 1.0 to tile the Bitmap as in the above example. If Clamp Horizontal or Clamp Vertical are selected, the Bitmap edge pixels will be repeated, instead.

Now that you’ve selected a Bitmap and defined how much of it will be used, you’re ready to select options for this Texture, located on the "Type" tab. If this Texture is going to be applied to polygons, you can set Type to either "Normal", causing the Texture to be applied to polygons like a layer of paint, or "Environment", causing the Texture to be applied to polygons like perfectly reflective chrome. If this Texture is going to be used by some other type of object instead, you can ignore Type.

tips: None.

 

questions or comments on this site? contact webmaster@k-3d.com

K-3D and the contents of this website copyright © 1995 - 1998 Shead Data Processing. all rights reserved.
Blue Moon Rendering Tools and BMRT copyright © 1990-1997 Larry I. Gritz. all rights reserved.
The RenderMan ® Interface Procedures and RIB Protocol are copyright © 1988, 1989, Pixar. all rights reserved.
RenderMan ® is a registered trademark of Pixar.all other copyrights and trademarks are the property of their respective owners.