vtContourConverter Class Reference

Public Member Functions
vtGeode *	Setup (vtTerrain *pTerr, const RGBf &color, float fHeight)
	Setup to generate geometry directly on a terrain. More...
bool	Setup (vtTerrain *pTerr, vtFeatureSetLineString *fset)
	Setup to generate line features. More...
void	GenerateContour (float fAlt)
void	GenerateContours (float fAInterval)
void	Finish ()

Detailed Description

This class provides the ability to easily construct contour lines on a terrain. It does so by calling the QuikGrid library to generate contour vectors, then converts those vectors into 3D line geometry draped on the terrain.

Here is an example of how to use it:

vtContourConverter cc;
cc.Setup(pTerrain, RGBf(1,1,0), 10);
cc.GenerateContours(100);
cc.Finish();

Or, you can generate specific contour lines:

vtContourConverter cc;
cc.Setup(pTerrain, RGBf(1,1,0), 10);
cc.GenerateContour(75);
cc.GenerateContour(125);
cc.GenerateContour(250);
cc.Finish();

If you keep a pointer to the geometry, you can toggle or delete it later:

vtContourConverter cc;
vtGeode *geode = cc.Setup(pTerrain, RGBf(1,1,0), 10);
[...]
geom->SetEnabled(bool);    // set visibility
[...]
pTerrain->GetScaledFeatures()->RemoveChild(geom);
geom->Release();       // delete

Member Function Documentation

void vtContourConverter::Finish

(

)

Finishes the contour generation process. Call once when you are done using the class to generate contours.

void vtContourConverter::GenerateContour

(

float

fAlt

)

Generate a contour line to be draped on the terrain.

Parameters

fAlt	The altitude (elevation) of the line to be generated.

void vtContourConverter::GenerateContours

(

float

fInterval

)

Generate a set of contour lines to be draped on the terrain.

Parameters

fInterval

The vertical spacing between the contours. For example, if the elevation range of your data is from 50 to 350 meters, then an fIterval of 100 will place contour bands at 100,200,300 meters.

vtGeode * vtContourConverter::Setup	(	vtTerrain *	pTerr,
		const RGBf &	color,
		float	fHeight
	)

Set up the class to create geometry on a terrain.

Parameters

pTerr	The terrain you will generate the contour lines on.
color	The colors of the generated lines.
fHeight	The height above the terrain to drape the lines. Generally you will want to use a small offset value here, to keep the lines from colliding with the terrain itself.

Returns

A geometry node which contains the contours.

bool vtContourConverter::Setup	(	vtTerrain *	pTerr,
		vtFeatureSetLineString *	fset
	)

Set up the class to create line features on a terrain.

Parameters

pTerr	The terrain you will generate the contour lines on.
fset	The featureset to receive the polylines.

Returns

True if successful.