Terrain - Surface

The Surface dialog for terrains specifies how the data surface that defines the terrain should be visualized. Includes options such as the texture used for the surface, the color determined by the elevation, the level of details computed and the size of the data set in view.

Surface Dialog Controls

	Palette	Choose from preset color gradients that will be used to color the surface based on the elevation value.
$images\btn_theme_apply.gif$	Apply	Apply the chosen palette to terrain.
$images\btn_theme_reverse.gif$	Reverse	Reverse the colors used in the values box from high to low.
$images\btn_theme_interpolate.gif$	Interpolate	Change the colors used in the values boxes by interpolating between the top and the bottom boxes. A quick way of creating smooth gradients of colors or sizes.
$images\btn_theme_lighten.gif$	Lighten	Lighten all colors in the values boxes. Each click of the Lighten button lightens the colors a bit more.
$images\btn_theme_darken.gif$	Darken	Darken all colors in the values boxes. Each click of the Darken button darkens the colors a bit more.
$images\btn_theme_grayscale.gif$	Grayscale	Convert all colors in the values boxes to grayscale.
$images\btn_open.gif$	Load from File	Load a previously saved palette from an XML file.
$images\btn_save.gif$	Save to File	Save this palette to an XML file.
	Texture	The texture applied to the surface, such as a variety of stone or other textures.
	Details	Choose a level of detail to be computed, from Full to Lowest. Higher levels of details will require more computation and will result in slower display within the terrain window.
	Display	The number of tiles to show in the terrain window. Terrains are subdivided into a smaller number of square tile regions, with each tile being 32 x 32 pixels. Operating with a larger number of tiles will increase the apparent extent of the surface in view in the terrain window. Increasing the number of tiles will slow down operation.
	Z scale	Factor to apply in rendering height. A value of 0.50 will render heights half as high as their elevation values would suggest. A value of 2.00 renders heights twice as high.
	Walls	Show the terrain with vertical "walls" at the edges of the terrain.
	Wireframe	Show the terrain as a wireframe mesh instead of as a continuous surface.
	Preview	Check this box to show the effect of options in the terrain window as they are altered.

Choose a collection of options, using Preview if desired to see the effects and then press OK to apply them to the terrain window.

$images\btn_theme_apply.gif$ When choosing a new palette, don't forget to press the Apply button to load the values from that palette.

Keyboard Shortcuts for Z Scale in Terrain Windows

With the focus on the terrain window we can use the following keyboard shortcuts to modify Z scale.

Page Up	Increase Z scale by .01
SHIFT-Page Up	Increase Z scale by .10
Home	Set Z scale to 1.0
Page Down	Decrease Z scale by .01
SHIFT-Page Down	Decrease Z scale by .10

Examples

$images\sc_terrain_texture_01.gif$

$images\sc_terrain_texture_02.gif$

Textures: The upper image has no texture applied. The bottom image has a rough surface texture applied. Textures can provide a greater sense of reality.

$images\sc_terrain_tiles_01.gif$

$images\sc_terrain_texture_02.gif$

$images\sc_terrain_tiles_02.gif$

Display: The three images above show an increasing number of tiles. The first image has the least number of tiles and shows terrain only in the foreground. The middle image adds more tiles, so the displayed terrain extends further towards the horizon. The last image has the greatest number of tiles used and so extends even further to the horizon. Tiles are square pieces of terrain that are 32 x 32 pixels in extent.

$images\sc_terrain_texture_02.gif$

$images\sc_terrain_details_01.gif$

Details: This setting specifies what percentage of the data set is used to render the 3D terrain. The upper image uses Full details while the lower image uses Lower details. Lower Details settings will display faster but will simplify the terrain by using fewer data points from the terrain data set. Note how the lower image is an interpolated approximation to the upper image.

Palettes are a sequence of colors that are applied to the 3D surface depending on the elevation of the surface. Manifold provides numerous preset palettes.

$images\sc_terrain_texture_01a.gif$

The palette used in the illustrations above will color the surface in a series of green colors from a lighter green to a green brown in higher elevations and then finally to a brighter green at the highest elevations.

$images\sc_terrain_texture_01.gif$

Most of the terrain visible in these illustrations, like the screen shot above, is at elevations lower than the dark brown band and is therefore colored in the lower two bands.

$images\sc_terrain_palette_01a.gif$

Palette colors can be changed at will. For example, we can double click into the green color well just before the brown well and change it to bright yellow.

$images\sc_terrain_palette_01.gif$

The result in the terrain window will be that terrain elevations from 1464 to 1922 will be colored bright yellow.

$images\sc_terrain_palette_02a.gif$

Different palettes may have greater or fewer divisions and color wells. Although many palettes are available to color terrains in a realistic way, some palettes are designed for use with purely abstract data.

$images\sc_terrain_palette_02.gif$

These may be applied to terrains for otherworldly effects, or simply to color-code data shown in the terrain window.

Wireframe

$images\sc_terrain_surf_dialog_all.gif$ $images\sc_terrain_surf_dialog_wire.gif$

The Wireframe option shows the terrain as a wireframe mesh instead of as a solid surface. The colors of the wires will be taken from the palette color and texture for that part of the surface.

Walls

$images\sc_terrain_surf_dialog_all.gif$ $images\sc_terrain_surf_dialog_nowalls.gif$

The Walls option turns on vertical panels that "close in" the area underneath the terrain and provide greater orientation when the terrain is seen from far away.