GeoMipTerrain, meaning Panda3D GeoMipMapping, can convert a heightfield image into a 3D terrain, consisting of several GeomNodes. More...

#include "geoMipTerrain.h"

Inheritance diagram for GeoMipTerrain:

Public Types
enum	AutoFlattenMode { AFM_off = 0, AFM_light = 1, AFM_medium = 2, AFM_strong = 3 }

Public Member Functions
	GeoMipTerrain (const std::string &name)

	~GeoMipTerrain ()
	This will not remove the terrain node itself. More...

void	calc_ambient_occlusion (PN_stdfloat radius=32, PN_stdfloat contrast=2.0f, PN_stdfloat brightness=0.75f)
	Calculates an approximate for the ambient occlusion and stores it in the color map, so that it will be written to the vertex colors. More...

void	clear_color_map ()
	Clears the color map. More...

PNMImage &	color_map ()
	Returns a reference to the color map (a PNMImage) contained inside GeoMipTerrain. More...

virtual TypeHandle	force_init_type ()

void	generate ()
	(Re)generates the entire terrain, erasing the current. More...

LVecBase2	get_block_from_pos (double x, double y)
	Gets the coordinates of the block at the specified position. More...

const NodePath	get_block_node_path (unsigned short mx, unsigned short my)
	Returns the NodePath of the specified block. More...

unsigned short	get_block_size ()
	Gets the block size. More...

bool	get_border_stitching ()
	Returns the current stitching setting. More...

bool	get_bruteforce ()
	Returns a boolean whether the terrain is rendered bruteforce or not. More...

double	get_elevation (double x, double y)
	Fetches the elevation at (x, y), where the input coordinate is specified in pixels. More...

double	get_far ()
	Returns the far LOD distance in the terrain coordinate space. More...

int	get_flatten_mode ()
	Returns the automatic-flatten mode (e.g., off, flatten_light, flatten_medium, or flatten_strong) More...

NodePath	get_focal_point () const
	Returns the focal point, as a NodePath. More...

unsigned short	get_max_level ()
	Returns the highest level possible for this block size. More...

unsigned short	get_min_level ()
	Gets the minimum level of detail at which blocks may be generated by generate() or update(). More...

double	get_near ()
	Returns the near LOD distance in the terrain coordinate space. More...

LVector3	get_normal (int x, int y)
	Fetches the terrain normal at (x, y), where the input coordinate is specified in pixels. More...

LVector3	get_normal (unsigned short mx, unsigned short my, int x, int y)
	Fetches the terrain normal at (x,y), where the input coordinate is specified in pixels. More...

NodePath	get_root () const
	Returns the root of the terrain. More...

virtual TypeHandle	get_type () const

bool	has_color_map () const
	Returns whether a color map has been set. More...

PNMImage &	heightfield ()
	Returns a reference to the heightfield (a PNMImage) contained inside GeoMipTerrain. More...

bool	is_dirty ()
	Returns a bool indicating whether the terrain is marked 'dirty', that means the terrain has to be regenerated on the next update() call, because for instance the heightfield has changed. More...

PNMImage	make_slope_image ()
	Returns a new grayscale image containing the slope angles. More...

void	set_auto_flatten (int mode)
	The terrain can be automatically flattened (using flatten_light, flatten_medium, or flatten_strong) after each update. More...

void	set_block_size (unsigned short newbs)
	Sets the block size. More...

void	set_border_stitching (bool stitching)
	If this value is true, the LOD level at the borders of the terrain will be 0. More...

void	set_bruteforce (bool bf)
	Sets a boolean specifying whether the terrain will be rendered bruteforce. More...

bool	set_color_map (const Filename &filename, PNMFileType *type=nullptr)
	Loads the specified image as color map. More...

bool	set_color_map (const PNMImage &image)

bool	set_color_map (const Texture *image)

bool	set_color_map (const std::string &path)

void	set_factor (PN_stdfloat factor)
	DEPRECATED method. More...

void	set_far (double input_far)
	Sets the far LOD distance, at which the terrain will be rendered at lowest quality. More...

void	set_focal_point (const LPoint2d &fp)

void	set_focal_point (const LPoint2f &fp)

void	set_focal_point (const LPoint3d &fp)

void	set_focal_point (const LPoint3f &fp)

void	set_focal_point (double x, double y)
	Sets the focal point. More...

void	set_focal_point (NodePath fnp)

bool	set_heightfield (const Filename &filename, PNMFileType *type=nullptr)
	Loads the specified heightmap image file into the heightfield. More...

bool	set_heightfield (const PNMImage &image)
	Loads the specified heightmap image file into the heightfield. More...

void	set_min_level (unsigned short minlevel)
	Sets the minimum level of detail at which blocks may be generated by generate() or update(). More...

void	set_near (double input_near)
	Sets the near LOD distance, at which the terrain will be rendered at highest quality. More...

void	set_near_far (double input_near, double input_far)
	Sets the near and far LOD distances in one call. More...

bool	update ()
	Loops through all of the terrain blocks, and checks whether they need to be updated. More...

Public Member Functions inherited from TypedObject
	TypedObject (const TypedObject &copy)=default

TypedObject *	as_typed_object ()
	Returns the object, upcast (if necessary) to a TypedObject pointer. More...

const TypedObject *	as_typed_object () const
	Returns the object, upcast (if necessary) to a TypedObject pointer. More...

int	get_best_parent_from_Set (const std::set< int > &) const

int	get_type_index () const
	Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. More...

bool	is_exact_type (TypeHandle handle) const
	Returns true if the current object is the indicated type exactly. More...

bool	is_of_type (TypeHandle handle) const
	Returns true if the current object is or derives from the indicated type. More...

TypedObject &	operator= (const TypedObject &copy)=default

Static Public Member Functions
static TypeHandle	get_class_type ()

static void	init_type ()

Static Public Member Functions inherited from TypedObject
static TypeHandle	get_class_type ()

static void	init_type ()
	This function is declared non-inline to work around a compiler bug in g++ 2.96. More...

Additional Inherited Members
Public Attributes inherited from TypedObject
	get_type

Detailed Description

GeoMipTerrain, meaning Panda3D GeoMipMapping, can convert a heightfield image into a 3D terrain, consisting of several GeomNodes.

It uses the GeoMipMapping algorithm, or Geometrical MipMapping, based on the LOD (Level of Detail) algorithm. For more information about the GeoMipMapping algoritm, see this paper, written by Willem H. de Boer: http://flipcode.com/articles/article_geomipmaps.pdf

Definition at line 36 of file geoMipTerrain.h.

Constructor & Destructor Documentation

◆ ~GeoMipTerrain()

GeoMipTerrain::~GeoMipTerrain ( )

inline

This will not remove the terrain node itself.

To have the terrain itself also deleted, please call remove_node() prior to destruction.

Definition at line 47 of file geoMipTerrain.I.

Member Function Documentation

◆ calc_ambient_occlusion()

void GeoMipTerrain::calc_ambient_occlusion	(	PN_stdfloat	radius = `32`,
		PN_stdfloat	contrast = `2.0f`,
		PN_stdfloat	brightness = `0.75f`
	)

Calculates an approximate for the ambient occlusion and stores it in the color map, so that it will be written to the vertex colors.

Any existing color map will be discarded. You need to call this before generating the geometry.

Definition at line 371 of file geoMipTerrain.cxx.

References PNMImage::gaussian_filter(), PNMImage::get_gray(), PNMImageHeader::get_maxval, PNMImage::make_grayscale(), PNMImage::set_maxval(), and PNMImage::set_xel().

◆ clear_color_map()

void GeoMipTerrain::clear_color_map ( )

inline

Clears the color map.

Definition at line 444 of file geoMipTerrain.I.

References PNMImage::clear().

◆ color_map()

PNMImage & GeoMipTerrain::color_map ( )

inline

Returns a reference to the color map (a PNMImage) contained inside GeoMipTerrain.

You can use the reference to alter the color map.

Definition at line 64 of file geoMipTerrain.I.

◆ generate()

void GeoMipTerrain::generate ( )

(Re)generates the entire terrain, erasing the current.

This call un- flattens the terrain, so make sure you have set auto-flatten if you want to keep your terrain flattened.

Definition at line 401 of file geoMipTerrain.cxx.

References NodePath::attach_new_node(), NodePath::node(), and PandaNode::remove_all_children().

Referenced by update().

◆ get_block_from_pos()

LVecBase2 GeoMipTerrain::get_block_from_pos	(	double	x,
		double	y
	)

inline

Gets the coordinates of the block at the specified position.

This position must be relative to the terrain, not to render. Returns an array containing two values: the block x and the block y coords. If the positions are out of range, the closest block is taken. Note that the VecBase returned does not represent a vector, position, or rotation, but it contains the block index of the block which you can use in GeoMipTerrain::get_block_node_path.

Definition at line 327 of file geoMipTerrain.I.

◆ get_block_node_path()

const NodePath GeoMipTerrain::get_block_node_path	(	unsigned short	mx,
		unsigned short	my
	)

inline

Returns the NodePath of the specified block.

If auto-flatten is enabled and the node is getting removed during the flattening process, it will still return a NodePath with the appropriate terrain chunk, but it will be in a temporary scenegraph. Please note that this returns a const object and you can not modify the node. Modify the heightfield instead.

Definition at line 311 of file geoMipTerrain.I.

◆ get_block_size()

unsigned short GeoMipTerrain::get_block_size ( )

inline

Gets the block size.

Definition at line 195 of file geoMipTerrain.I.

◆ get_border_stitching()

bool GeoMipTerrain::get_border_stitching ( )

inline

Returns the current stitching setting.

False by default, unless set_stitching has been set.

Definition at line 471 of file geoMipTerrain.I.

◆ get_bruteforce()

bool GeoMipTerrain::get_bruteforce ( )

inline

Returns a boolean whether the terrain is rendered bruteforce or not.

See set_bruteforce for more information.

Definition at line 86 of file geoMipTerrain.I.

◆ get_elevation()

double GeoMipTerrain::get_elevation	(	double	x,
		double	y
	)

Fetches the elevation at (x, y), where the input coordinate is specified in pixels.

This ignores the current LOD level and instead provides an accurate number. Linear blending is used for non-integral coordinates. Terrain scale is NOT taken into account! To get accurate normals, please multiply this with the terrain Z scale!

trueElev = terr.get_elevation(x,y) * terr.get_sz();

Definition at line 282 of file geoMipTerrain.cxx.

◆ get_far()

double GeoMipTerrain::get_far ( )

inline

Returns the far LOD distance in the terrain coordinate space.

Definition at line 282 of file geoMipTerrain.I.

◆ get_flatten_mode()

int GeoMipTerrain::get_flatten_mode ( )

inline

Returns the automatic-flatten mode (e.g., off, flatten_light, flatten_medium, or flatten_strong)

Definition at line 299 of file geoMipTerrain.I.

◆ get_focal_point()

NodePath GeoMipTerrain::get_focal_point ( ) const

inline

Returns the focal point, as a NodePath.

If you have set it to be just a point, it will return an empty node at the focal position.

Definition at line 146 of file geoMipTerrain.I.

◆ get_max_level()

unsigned short GeoMipTerrain::get_max_level ( )

inline

Returns the highest level possible for this block size.

When a block is at this level, it will be the worst quality possible.

Definition at line 187 of file geoMipTerrain.I.

◆ get_min_level()

unsigned short GeoMipTerrain::get_min_level ( )

inline

Gets the minimum level of detail at which blocks may be generated by generate() or update().

The default value is 0, which is the highest quality.

Definition at line 178 of file geoMipTerrain.I.

◆ get_near()

double GeoMipTerrain::get_near ( )

inline

Returns the near LOD distance in the terrain coordinate space.

Definition at line 290 of file geoMipTerrain.I.

◆ get_normal() [1/2]

LVector3 GeoMipTerrain::get_normal	(	int	x,
		int	y
	)

Fetches the terrain normal at (x, y), where the input coordinate is specified in pixels.

This ignores the current LOD level and instead provides an accurate number. Terrain scale is NOT taken into account! To get accurate normals, please divide it by the terrain scale and normalize it again, like this:

LVector3 normal (terr.get_normal(x, y)); normal.set(normal.get_x() / root.get_sx(), normal.get_y() / root.get_sy(), normal.get_z() / root.get_sz()); normal.normalize();

Definition at line 317 of file geoMipTerrain.cxx.

Referenced by make_slope_image().

◆ get_normal() [2/2]

LVector3 GeoMipTerrain::get_normal	(	unsigned short	mx,
		unsigned short	my,
		int	x,
		int	y
	)

inline

Fetches the terrain normal at (x,y), where the input coordinate is specified in pixels.

This ignores the current LOD level and instead provides an accurate number. Terrain scale is NOT taken into account! To get accurate normals, please divide it by the terrain scale and normalize it again!

Definition at line 508 of file geoMipTerrain.I.

◆ get_root()

NodePath GeoMipTerrain::get_root ( ) const

inline

Returns the root of the terrain.

This is a single PandaNode to which all the rest of the terrain is parented. The generate and update operations replace the nodes which are parented to this root, but they don't replace this root itself.

Definition at line 157 of file geoMipTerrain.I.

◆ has_color_map()

bool GeoMipTerrain::has_color_map ( ) const

inline

Returns whether a color map has been set.

Definition at line 436 of file geoMipTerrain.I.

◆ heightfield()

PNMImage & GeoMipTerrain::heightfield ( )

inline

Returns a reference to the heightfield (a PNMImage) contained inside GeoMipTerrain.

You can use the reference to alter the heightfield.

Definition at line 55 of file geoMipTerrain.I.

◆ is_dirty()

bool GeoMipTerrain::is_dirty ( )

inline

Returns a bool indicating whether the terrain is marked 'dirty', that means the terrain has to be regenerated on the next update() call, because for instance the heightfield has changed.

Once the terrain has been regenerated, the dirty flag automatically gets reset internally.

Definition at line 230 of file geoMipTerrain.I.

◆ make_slope_image()

PNMImage GeoMipTerrain::make_slope_image ( )

Returns a new grayscale image containing the slope angles.

A white pixel value means a vertical slope, while a black pixel will mean that the terrain is entirely flat at that pixel. You can translate it to degrees by mapping the greyscale values from 0 to 90 degrees. The resulting image will have the same size as the heightfield image. The scale will be taken into respect – meaning, if you change the terrain scale, the slope image will need to be regenerated in order to be correct.

Definition at line 348 of file geoMipTerrain.cxx.

References get_normal(), PNMImage::make_grayscale(), and PNMImage::set_xel().

◆ set_auto_flatten()

void GeoMipTerrain::set_auto_flatten ( int mode )

inline

The terrain can be automatically flattened (using flatten_light, flatten_medium, or flatten_strong) after each update.

This only affects future updates, it doesn't flatten the current terrain.

Definition at line 96 of file geoMipTerrain.I.

◆ set_block_size()

void GeoMipTerrain::set_block_size ( unsigned short newbs )

inline

Sets the block size.

If it is not a power of two, the closest power of two is used.

Definition at line 204 of file geoMipTerrain.I.

◆ set_border_stitching()

void GeoMipTerrain::set_border_stitching ( bool stitching )

inline

If this value is true, the LOD level at the borders of the terrain will be 0.

This is useful if you have multiple terrains attached and you want to stitch them together, to fix seams. This setting also has effect when bruteforce is enabled, although in that case you are probably better off with setting the minlevels to the same value.

Definition at line 459 of file geoMipTerrain.I.

◆ set_bruteforce()

void GeoMipTerrain::set_bruteforce ( bool bf )

inline

Sets a boolean specifying whether the terrain will be rendered bruteforce.

If the terrain is rendered bruteforce, there will be no Level of Detail, and the update() call will only update the terrain if it is marked dirty.

Definition at line 74 of file geoMipTerrain.I.

◆ set_color_map()

bool GeoMipTerrain::set_color_map	(	const Filename &	filename,
		PNMFileType *	ftype = `nullptr`
	)

inline

Loads the specified image as color map.

The next time generate() is called, the terrain is painted with this color map using the vertex color column. Returns a boolean indicating whether the operation has succeeded.

Definition at line 403 of file geoMipTerrain.I.

References PNMImage::read().

◆ set_factor()

void GeoMipTerrain::set_factor ( PN_stdfloat factor )

inline

DEPRECATED method.

Use set_near/far instead. Sets the quality factor at which blocks must be generated. The higher this level, the better quality the terrain will be, but more expensive to render. A value of 0 makes the terrain the lowest quality possible, depending on blocksize. The default value is 100.

Definition at line 242 of file geoMipTerrain.I.

◆ set_far()

void GeoMipTerrain::set_far ( double input_far )

inline

Sets the far LOD distance, at which the terrain will be rendered at lowest quality.

This distance is in the terrain's coordinate space!

Definition at line 273 of file geoMipTerrain.I.

◆ set_focal_point()

void GeoMipTerrain::set_focal_point	(	double	x,
		double	y
	)

inline

Sets the focal point.

GeoMipTerrain generates high-resolution terrain around the focal point, and progressively lower and lower resolution terrain as you get farther away. If a point is supplied and not a NodePath, make sure it's relative to the terrain. Only the x and y coordinates of the focal point are taken in respect.

Definition at line 108 of file geoMipTerrain.I.

◆ set_heightfield() [1/2]

bool GeoMipTerrain::set_heightfield	(	const Filename &	filename,
		PNMFileType *	ftype = `nullptr`
	)

Loads the specified heightmap image file into the heightfield.

Returns true if succeeded, or false if an error has occured. If the heightmap is not a power of two plus one, it is scaled up using a gaussian filter.

Definition at line 619 of file geoMipTerrain.cxx.

References PNMImage::copy_header_from(), PNMImageHeader::get_color_space, PNMImageHeader::get_x_size(), PNMImageHeader::get_y_size(), PNMImageHeader::read_header(), and PNMImage::set_read_size().

◆ set_heightfield() [2/2]

bool GeoMipTerrain::set_heightfield ( const PNMImage & image )

inline

Loads the specified heightmap image file into the heightfield.

Returns true if succeeded, or false if an error has occured. If the heightmap is not a power of two plus one, it is scaled up using a gaussian filter.

Definition at line 373 of file geoMipTerrain.I.

References PNMImage::get_color_space().

◆ set_min_level()

void GeoMipTerrain::set_min_level ( unsigned short minlevel )

inline

Sets the minimum level of detail at which blocks may be generated by generate() or update().

The default value is 0, which is the highest quality. This value is also taken in respect when generating the terrain bruteforce.

Definition at line 168 of file geoMipTerrain.I.

◆ set_near()

void GeoMipTerrain::set_near ( double input_near )

inline

Sets the near LOD distance, at which the terrain will be rendered at highest quality.

This distance is in the terrain's coordinate space!

Definition at line 263 of file geoMipTerrain.I.

◆ set_near_far()

void GeoMipTerrain::set_near_far	(	double	input_near,
		double	input_far
	)

inline

Sets the near and far LOD distances in one call.

Definition at line 252 of file geoMipTerrain.I.

◆ update()

bool GeoMipTerrain::update ( )

Loops through all of the terrain blocks, and checks whether they need to be updated.

If that is indeed the case, it regenerates the mipmap. Returns a true when the terrain has changed. Returns false when the terrain isn't updated at all. If there is no terrain yet, it generates the entire terrain. This call un-flattens the terrain, so make sure you have set auto-flatten if you want to keep your terrain flattened.

Definition at line 439 of file geoMipTerrain.cxx.

References generate(), NodePath::node(), and PandaNode::remove_all_children().

The documentation for this class was generated from the following files:

panda/src/grutil/geoMipTerrain.h
panda/src/grutil/geoMipTerrain.cxx
panda/src/grutil/geoMipTerrain.I

Public Types

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ~GeoMipTerrain()

Member Function Documentation

◆ calc_ambient_occlusion()

◆ clear_color_map()

◆ color_map()

◆ generate()

◆ get_block_from_pos()

◆ get_block_node_path()

◆ get_block_size()

◆ get_border_stitching()

◆ get_bruteforce()

◆ get_elevation()

◆ get_far()

◆ get_flatten_mode()

◆ get_focal_point()

◆ get_max_level()

◆ get_min_level()

◆ get_near()

◆ get_normal() [1/2]

◆ get_normal() [2/2]

◆ get_root()

◆ has_color_map()

◆ heightfield()

◆ is_dirty()

◆ make_slope_image()

◆ set_auto_flatten()

◆ set_block_size()

◆ set_border_stitching()

◆ set_bruteforce()

◆ set_color_map()

◆ set_factor()

◆ set_far()

◆ set_focal_point()

◆ set_heightfield() [1/2]

◆ set_heightfield() [2/2]

◆ set_min_level()

◆ set_near()

◆ set_near_far()

◆ update()