INDEX

### NVIZ - Surfaces

Use Surface panel options to manage surfaces to be drawn. The top half of the panel contains options for drawing style. The bottom half is used to add and delete surfaces and change attributes on the current surface. After options are set, click on Surface in the Movement panel to see the results.

### Surface Panel

Grid Resolution
  sets number of cells between grid lines when drawing wire grids (in both fast display mode and Draw mode). A larger grid resolution number produces a more sparse grid.

Poly Resolution
  sets number of cells to be used as dimensions of each polygon drawn when drawing polygons. Each drawn polygon actually represents (Poly Res x Poly Res) cells.

Current Surface Only
  Option changes effect currently selected surface only.

All Surfaces
  Option changes effect all surfaces.

Surface Style
  Polygon
    draw surface using filled polygons (most realistic).
  Wire
    draw surface with a wire mesh. This differs from the mesh drawn in fast display mode in that hidden lines are not drawn.
  Wire/Poly
    draw surface as polygons, but with wire mesh draped over it.

Shading
  Gouraud
    smooth shade surface to blend individual cell colors together.
  Flat
    Surfaces are drawn with flat shading. One color for each of the two triangles that form a cell. The surface will appear faceted.

Current
  displays name of currently selected surface. Pressing the left mouse button over the name causes a menu of all available surfaces to appear. A new current surface can be selected from this menu.

New
  Load a new surface. This button pops up a Change Attribute window (see below) which allows the selection of a new map or constant for a surface.

Delete
  Delete current surface. This merely unloads surface data. nviz will not change any files that exist in your GRASS database.

No Zeros
  do not draw surface where elevation data values are zero. The second No Zeros toggle causes areas where the color values are zero not to be drawn.

Wire Color
  Select a wire color for current surface with a Select Color popup (see below).

Position
  change x, y, and z position of current surface using Position Surface popup window (see below).

Draw Current
  render only the current surface using the given rendering parameters.

The rest of the buttons on this panel control attributes of the current surface. The current value of that attribute appears to the right of the attribute button. Clicking on an attribute button pops up a Change Attribute window (see below) which allows the selection of a new map or constant for that attribute.

Topography
  Map or constant which controls elevation (z values) of surface.

Color
  Map or constant which controls surface color.

Mask
  Map or constant which controls which areas of surface are drawn.

Transparency
  Map or constant which controls transparency level of surface (all opaque is default).

Shininess
  Map or constant which controls shininess (reflectivity) of surface material.

Emission
  Map or constant which controls light emitted from surface.