VRML Script Tutorial
VRML Interactive Tutorial
Let there be Light
Materials with Colored Lights
VRML File Structure
Drawing: Shape node
Hierarchical Node Structures
Defining and Instancing Nodes
Defining Levels of Detail
Events in VRML
Let the Music Play
Adding Realism to the world
Information about your world
Definition for Auxiliary Nodes
The ElevationGrid node specifies a grid of points, each with a used defined
height. This node is useful to create meshes, see Lighting,
or to build a terrain.
An ElevationGrid is built in the XZ plane, starting from the origin and
expanding in the positive direction of the axes. The shape of an ElevationGrid
is defined by the following fields:
xDimension: the number of points in the grid along the X axis.
zDimension: the number of grid points in the Z axis.
xSpacing: the distance between two adjacent points in the X axis direction.
zSpacing: the distance between two adjacent points in the Z axis direction.
height: a list of floating point values specifying the height for each
point in the grid. The points are ordered left to right and top to bottom.
The other fields for this node are:
The color field defines a Color
node. This node defines a list of colors to apply to the faces. The color
is optional, the default values being applied if the field is not specified.
If a Material node is specified
the default color is the emissive color from this node. Note that both
the default emissive color and background are black, so if no color is
specified and the default background is used you won't be able to see the
The colorPerVertex is a boolean field which defines how the colors
are applied. The meaning is similar to the IndexedLineSet
texCoord specifies a TextureCoordinate
There are 2 normal fields which have the same meaning than the color fields
but applied to normals. The normal
field defines a Normal node.
The ccw field specifies if the points which define a face are present
counterclockwise, TRUE, or clockwise or unknown order, FALSE. A face has
two sides and sometimes it is important to know which is the front side,
and which is the back side. So let's assume you're defining s single face
perpendicular to the Z axis and ccw is TRUE. If the face is defined
counterclockwise then the front side is the side facing you. Otherwise
the back side is facing you. If ccw is FALSE then the opposite occurs.
The solid field determines if the browser should draw both sides
of a face or just the front side. VRML assumes by default, solid is
TRUE that the faces in an IndexedFaceSet form a solid shape. In this case
there is no need to draw the back sides of each face. If solid is
FALSE then the browser will draw both sides of each face.
The convex field specifies if the faces being defined in coordIndex
are convex or not. VRML can only draw convex faces. When presented
with concave faces, the browser splits the face into smaller convex faces.
This is a time consuming task. If you are sure that all your faces are
convex then setting this field to TRUE tells the browser not to worry splitting
the faces, and therefore saving time. The creaseAngle specifies
an angle threshold. If two adjacent faces make an angle bigger than the
creaseAngle then you'll see clearly where the two faces meet, the edge
linking the two faces is sharp. Otherwise the edge linking the two faces
will be smooth.
height [ ]
The following figure depicts the grid built using this node using a list
of heights with all elements equal to 0.0.