# GeoMipTerrain

from pandac.PandaModules import GeoMipTerrain

Class : GeoMipTerrain
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

## Inheritance:

GeoMipTerrain: TypedObject
TypedObject: MemoryBase
MemoryBase:

## Methods of GeoMipTerrain:

GeoMipTerrain (Constructor)
clearColorMap
colorMap
generate
getBlockFromPos
getBlockNodePath
getBlockSize
getBruteforce
getClassType
getElevation
getFocalPoint
getMaxLevel
getMinLevel
getNormal
getRoot
hasColorMap
heightfield
isDirty
makeSlopeImage
setAutoFlatten
setBlockSize
setBruteforce
setColorMap
setFactor
setFar
setFocalPoint
setHeightfield
setMinLevel
setNear
setNearFar
update

## Methods of TypedObject:

getClassType
getType
getTypeIndex
isExactType
isOfType

## Constants in GeoMipTerrain:

AFMOff | (AutoFlattenMode)
AFMLight | (AutoFlattenMode)
AFMMedium | (AutoFlattenMode)
AFMStrong | (AutoFlattenMode)

GeoMipTerrain GeoMipTerrain::GeoMipTerrain(string const &name); Description:

clearColorMap void GeoMipTerrain::clear_color_map(void); Description: Clears the color map.

colorMap PNMImage &GeoMipTerrain::color_map(void); Description: Returns a reference to the color map (a PNMImage) contained inside GeoMipTerrain. You can use the reference to alter the color map.

generate void GeoMipTerrain::generate(void); Description: (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.

getBlockFromPos LVecBase2f GeoMipTerrain::get_block_from_pos(double x, double y); Description: 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.

getBlockNodePath NodePath const GeoMipTerrain::get_block_node_path(unsigned short int mx, unsigned short int my); Description: 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.

getBlockSize unsigned short int GeoMipTerrain::get_block_size(void); Description: Gets the block size.

getBruteforce bool GeoMipTerrain::get_bruteforce(void); Description: Returns a boolean whether the terrain is rendered bruteforce or not. See set_bruteforce for more information.

getClassType static TypeHandle GeoMipTerrain::get_class_type(void); Undocumented function.

getElevation double GeoMipTerrain::get_elevation(double x, double y); Description: 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();

getFocalPoint NodePath GeoMipTerrain::get_focal_point(void) const; Description: 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.

getMaxLevel unsigned short int GeoMipTerrain::get_max_level(void); Description: Returns the highest level possible for this block size. When a block is at this level, it will be the worst quality possible.

getMinLevel unsigned short int GeoMipTerrain::get_min_level(void); Description: 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.

getNormal LVector3f GeoMipTerrain::get_normal(int x, int y); Description: 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! Description: 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: LVector3f 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();

getRoot NodePath GeoMipTerrain::get_root(void) const; Description: 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.

hasColorMap bool GeoMipTerrain::has_color_map(void); Description: Returns whether a color map has been set.

heightfield PNMImage &GeoMipTerrain::heightfield(void); Description: Returns a reference to the heightfield (a PNMImage) contained inside GeoMipTerrain. You can use the reference to alter the heightfield.

isDirty bool GeoMipTerrain::is_dirty(void); Description: 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.

makeSlopeImage PNMImage GeoMipTerrain::make_slope_image(void); Description: 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.

setAutoFlatten void GeoMipTerrain::set_auto_flatten(int mode); Description: 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.

setBlockSize void GeoMipTerrain::set_block_size(unsigned short int newbs); Description: Sets the block size. If it is not a power of two, the closest power of two is used.

setBruteforce void GeoMipTerrain::set_bruteforce(bool bf); Description: 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.

setColorMap bool GeoMipTerrain::set_color_map(Filename const &filename, PNMFileType *type = ((void *)(0))); Description: 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.

setFactor void GeoMipTerrain::set_factor(float factor); Description: 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.

setFar void GeoMipTerrain::set_far(double input_far); Description: Sets the far LOD distance, at which the terrain will be rendered at lowest quality. This distance is in the terrain's coordinate space!

setFocalPoint void GeoMipTerrain::set_focal_point(LPoint2d fp); The focal point is the point at which the terrain will have the highest quality (lowest level of detail). Parts farther away from the focal point will have a lower quality (higher level of detail). The focal point is not taken in respect if bruteforce is set true. Description: 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.

setHeightfield bool GeoMipTerrain::set_heightfield(Filename const &filename, PNMFileType *type = ((void *)(0))); Description: 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.

setMinLevel void GeoMipTerrain::set_min_level(unsigned short int minlevel); Description: 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.

setNear void GeoMipTerrain::set_near(double input_near); Description: Sets the near LOD distance, at which the terrain will be rendered at highest quality. This distance is in the terrain's coordinate space!

setNearFar void GeoMipTerrain::set_near_far(double input_near, double input_far); Description: Sets the near and far LOD distances in one call.

update bool GeoMipTerrain::update(void); Description: 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.

getClassType static TypeHandle TypedObject::get_class_type(void); Undocumented function.

getType virtual TypeHandle TypedObject::get_type(void) const = 0; Derived classes should override this function to return get_class_type().

getTypeIndex int TypedObject::get_type_index(void) const; Description: Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. This is equivalent to get_type().get_index().

isExactType bool TypedObject::is_exact_type(TypeHandle handle) const; Description: Returns true if the current object is the indicated type exactly.

isOfType bool TypedObject::is_of_type(TypeHandle handle) const; Description: Returns true if the current object is or derives from the indicated type.