Unigine.LandscapeFetch Class
This class is used to fetch data of the Landscape Terrain Object at a certain point (e.g. a height request) or check for an intersection with a traced line. The following performance optimizations are available:
- For each request you can engage or disengage certain data types (albedo, heights, masks, etc.). When the data type is engaged, you can obtain information via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
- Both fetch and intersection requests can be performed asynchronously when an instant result is not required.
The workflow is as follows:
- Create a new LandscapeFetch object instance.
- Set necessary parameters (e.g. which data layers are to be used, whether to enable holes or not, etc.).
- To get terrain data for a certain point call the fetchForce() method providing coordinates for the desired point.NoticeYou can also fetch terrain data asynchronously via the fetchAsync() method.
- To find an intersection of a traced line with the terrain call either the intersectionForce() method or the intersectionAsync() method, if you want to perform an asynchronous request.
Usage Example#
Source code (C++)
// creating a fetch object and setting necessary parameters
LandscapeFetchPtr landscape_fetch = LandscapeFetch::create();
landscape_fetch->setUses(0);
landscape_fetch->setUsesHeight(true);
landscape_fetch->setHolesEnabled(true);
landscape_fetch->setBicubicFilterHeight(true);
// ...
// getting terrain data for a point at (100, 100) and printing the height value
if (landscape_fetch->fetchForce(Vec2(100, 100)))
Log::message("Terrain height at the specified point is: %f", Scalar(landscape_fetch->getHeight()));Asynchronous Operations Example#
Source code (C++)
// creating a fetch object and setting necessary parameters
LandscapeFetchPtr landscape_fetch = LandscapeFetch::create();
landscape_fetch->setUses(0);
landscape_fetch->setUsesHeight(true);
landscape_fetch->setHolesEnabled(true);
landscape_fetch->setBicubicFilterHeight(true);
// ...
// making an asynchronous fetch request for a point at (100, 100)
landscape_fetch->fetchAsync(Vec2(2.05f, 2.05f));
// ...
// checking if our asynchronous fetch request is completed and printing the height value
if (landscape_fetch->isAsyncCompleted()) {
Log::message("Terrain height at the specified point is: %f", Scalar(landscape_fetch->getHeight()));
}LandscapeFetch Class
Properties
vec3 Position#
Returns the coordinates of the fetch/intersection point.
float Height#
Returns the height value at the point.
vec3 Normal#
Returns normal vector coordinates at the point.
Notice
To get valid normal information via this method, engage normal data for the fetch/intersection request.
vec3 Tangent#
Returns tangent vector coordinates at the point.
Notice
To get valid tangent information via this method, engage normal data for the fetch/intersection request.
vec3 Binormal#
Returns binormal vector coordinates at the point.
Notice
To get valid binormal information via this method, engage normal data for the fetch/intersection request.
vec4 Albedo#
Returns albedo color information at the point.
Notice
To get valid albedo color information via this method, engage albedo data for the fetch/intersection request.
bool IsIntersection#
Returns a value indicating if an intersection was detected.
int Uses#
Returns the current state of flags engaging/disengaging certain data types for the fetch/intersection request.
set
Sets multiple flags engaging/disengaging certain data types for the fetch/intersection request.
set value -
Combination of data engagement flags to be set.
bool IsUsesHeight#
Returns a value indicating if heights data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point). This option is enabled by default.
set
Sets a value indicating if heights data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point). This option is enabled by default.
set value -
true to engage height data in the fetch/intersection request, false - to disengage.
bool IsUsesNormal#
Returns a value indicating if normals data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
set
Sets a value indicating if normals data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
set value -
true to engage normals data in the fetch/intersection request, false - to disengage.
bool IsUsesAlbedo#
Returns a value indicating if albedo data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
Notice
Enable this option to get albedo information for the point.
set
Sets a value indicating if albedo data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
Notice
Enable this option to get albedo information for the point.
set value -
true to engage albedo data in the fetch/intersection request, false - to disengage.
bool IsBicubicFilterHeight#
Returns a value indicating if bicubic filtering for height texture is enabled.
Notice
For best accuracy this setting should match the same setting for the Object Landscape Terrain.
set
Sets a value indicating if bicubic filtering for height texture is enabled.
Notice
For best accuracy this setting should match the same setting for the Object Landscape Terrain.
set value -
true to enable bicubic filtering for height texture, false - to disable it.
bool IsBicubicFilterNormal#
Returns a value indicating if bicubic filtering for normals texture is enabled.
Notice
For best accuracy this setting should match the same setting for the Object Landscape Terrain.
set
Sets a value indicating if bicubic filtering for normals texture is enabled.
Notice
For best accuracy this setting should match the same setting for the Object Landscape Terrain.
set value -
true to enable bicubic filtering for normals texture, false - to disable it.
float PrecisionBegin#
Returns the current start precision value used for intersection detection requested by intersectionForce() and intersectionAsync() methods. Intersections are detected with a variable precision, starting from lower value and ending up with a higher one.
Notice
Normally there's no need to modify this value. In case of intersection detection errors you can try tweaking start and end precision values for optimum balance, but be careful as it may significantly affect performance and accuracy.
set
Sets a new start precision value to be used for intersection detection requested by intersectionForce() and intersectionAsync() methods. Intersections are detected with a variable precision, starting from lower value and ending up with a higher one.
Notice
Normally there's no need to modify this value. In case of intersection detection errors you can try tweaking start and end precision values for optimum balance, but be careful as it may significantly affect performance and accuracy.
set value -
Start precision for intersection detection as a fraction of maximum precision in the [0; 1] range. The default value is 0.5f. Maximum precision is determined by the Engine on the basis of the data of your Landscape Terrain.
float PrecisionEnd#
Returns the current end precision value used for intersection detection requested by intersectionForce() and intersectionAsync() methods. Intersections are detected with a variable precision, starting from lower value and ending up with a higher one.
Notice
Normally there's no need to modify this value. In case of intersection detection errors you can try tweaking start and end precision values for optimum balance, but be careful as it may significantly affect performance and accuracy.
set
Sets a new end precision value to be used for intersection detection requested by intersectionForce() and intersectionAsync() methods. Intersections are detected with a variable precision, starting from lower value and ending up with a higher one.
Notice
Normally there's no need to modify this value. In case of intersection detection errors you can try tweaking start and end precision values for optimum balance, but be careful as it may significantly affect performance and accuracy.
set value -
End precision for intersection detection as a fraction of maximum precision in the [0; 1] range. The default value is 1.0f. Maximum precision is determined by the Engine on the basis of the data of your Landscape Terrain.
bool IsAsyncCompleted#
Returns a value indicating if async operation is completed. As the operation is completed you can obtain necessary data via get*() methods.
bool IsHolesEnabled#
A value indicating if checking for terrain holes in the fetch/intersection request is enabled. this option is enabled by default. when disabled terrain holes created using decals are ignored.
set
Sets a value indicating if checking for terrain holes in the fetch/intersection request is enabled. This option is enabled by default. When disabled terrain holes created using decals are ignored.
set value -
true to enable checking for terrain holes in the fetch/intersection request, false - to disable it.
Members
LandscapeFetch ( ) #
The LandscapeFetch constructor.float GetMask ( int num ) #
Returns information stored for the point in the detail mask with the specified number.Notice
To get valid detail mask information via this method, engage mask data for the fetch/intersection request.
Arguments
- int num - Number of the detail mask in the [0; 19] range.
Return value
Value for the point stored in the detail mask with the specified number.void SetUsesMask ( int num, bool value ) #
Sets a value indicating if data of the specified detail mask is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).Notice
Enable this option to get detail mask data for the point.
Arguments
- int num - Detail mask number in the [0; 19] range.
- bool value - true to engage data of the specified detail mask in the fetch/intersection request, false - to disengage.
bool IsUsesMask ( int num ) #
Returns a value indicating if data of the specified detail mask is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).Notice
Enable this option to get detail mask data for the point.
Arguments
- int num - Detail mask number in the [0; 19] range.
Return value
true if data of the specified detail mask is engaged in the fetch/intersection request; otherwise, false.bool FetchForce ( vec2 position ) #
Fetches terrain data for the point with the specified coordinates in forced mode. You can use the fetchAsync() method to reduce load, when an instant result is not required.Arguments
- vec2 position - Two-component vector specifying point coordinates along X and Y axes.
Return value
true if terrain data was successfully obtained for the specified point; otherwise, false.bool IntersectionForce ( vec3 p0, vec3 p1 ) #
Performs tracing along the line from the p0 point to the p1 point to find an intersection with the terrain in forced mode. You can use the intersectionAsync() method to reduce load, when an instant result is not required.Arguments
- vec3 p0 - Line start point coordinates.
- vec3 p1 - Line end point coordinates.
Return value
true if an intersection with the terrain was found; otherwise, false.void FetchAsync ( vec2 position, bool critical = false ) #
Fetches terrain data for the point with the specified coordinates in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the fetchForce() method.Arguments
- vec2 position - Two-component vector specifying point coordinates along X and Y axes.
- bool critical - true to set high priority for the fetch task, false - to set normal priority.
void IntersectionAsync ( vec3 p0, vec3 p1, bool critical = false ) #
Performs tracing along the line from the p0 point to the p1 point to find an intersection with the terrain in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the intersectionForce() method.Arguments
- vec3 p0 - Line start point coordinates.
- vec3 p1 - Line end point coordinates.
- bool critical - true to set high priority for the intersection task, false - to set normal priority.
static void FetchForce ( LandscapeFetch[] fetches, vec2 position ) #
Fetches terrain data for the point with the specified coordinates in forced mode. You can use the fetchAsync() method to reduce load, when an instant result is not required.Arguments
- LandscapeFetch[] fetches - List of fetch requests to be completed.
- vec2 position - Two-component vector specifying point coordinates along X and Y axes.
static void IntersectionForce ( LandscapeFetch[] fetches, vec3 p0, vec3 p1 ) #
Performs tracing along the line from the p0 point to the p1 point to find an intersection with the terrain in forced mode. You can use the intersectionAsync() method to reduce load, when an instant result is not required.Arguments
- LandscapeFetch[] fetches - List of fetch requests to be completed.
- vec3 p0 - Line start point coordinates.
- vec3 p1 - Line end point coordinates.
static void FetchAsync ( LandscapeFetch[] fetches, vec2 position, bool critical = false ) #
Fetches terrain data for the point with the specified coordinates in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the fetchForce() method.Arguments
- LandscapeFetch[] fetches - List of fetch requests to be completed.
- vec2 position - Two-component vector specifying point coordinates along X and Y axes.
- bool critical - true to set high priority for the fetch task, false - to set normal priority.
static void IntersectionAsync ( LandscapeFetch[] fetches, vec3 p0, vec3 p1, bool critical = false ) #
Performs tracing along the line from the p0 point to the p1 point to find an intersection with the terrain in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the intersectionForce() method.Arguments
- LandscapeFetch[] fetches - List of fetch requests to be completed.
- vec3 p0 - Line start point coordinates.
- vec3 p1 - Line end point coordinates.
- bool critical - true to set high priority for the intersection task, false - to set normal priority.
void Wait ( ) #
Waits for completion of the fetch operation. As the operation is completed you can obtain necessary data via get*() methods.static void Wait ( LandscapeFetch[] fetches ) #
Waits for completion of the specified fetch operations. As the operations are completed you can obtain necessary data via get*() methods.Arguments
- LandscapeFetch[] fetches - List of fetch requests to be completed.
IntPtr AddStartCallback ( StartDelegate func ) #
Adds a callback function to be called on fetch completion. The signature of the callback function must be as follows:Source code (C#)
void fetch_start_callback();You can set a callback function as follows:
Source code (C#)
AddStartCallback(()
=> fetch_start_callback());Example: Setting a fetch start callback function:
Source code (C#)
class AppWorldLogic : WorldLogic
{
/*...*/
// callback function implementing certain actions to be performed on beginning of the fetch process
private void FetchStart()
{
// insert your specific handling code here
}
/*...*/
public override bool Init()
{
// setting the FetchStart() function to handle beginning of the fetch process
LandscapeFetch lf = new LandscapeFetch();
lf.AddStartCallback(()
=> FetchStart(creator));
return true;
}
/*...*/
}Arguments
- StartDelegate func - Callback function with the following signature:
void StartDelegate()
Return value
ID of the last added fetch start callback, if the callback was added successfully; otherwise, null. This ID can be used to remove this callback when necessary.bool RemoveStartCallback ( IntPtr id ) #
Removes the specified callback from the list of file fetch start callbacks.Arguments
- IntPtr id - Start callback ID obtained when adding it.
Return value
True if the fetch start callback with the given ID was removed successfully; otherwise false.void ClearStartCallback ( ) #
Clears all added fetch start callbacks.IntPtr AddEndCallback ( EndDelegate func ) #
Adds a callback function to be called on fetch completion. The signature of the callback function must be as follows:Source code (C#)
void fetch_end_callback();You can set a callback function as follows:
Source code (C#)
AddEndCallback(()
=> fetch_end_callback());Example: Setting a fetch completion callback function:
Source code (C#)
class AppWorldLogic : WorldLogic
{
/*...*/
// callback function implementing certain actions to be performed on fetch completion
private void FetchEnd()
{
// insert your specific handling code here
}
/*...*/
public override bool Init()
{
// setting the FetchEnd() function to handle fetch completion
LandscapeFetch lf = new LandscapeFetch();
lf.AddEndCallback(()
=> FetchEnd(creator));
return true;
}
/*...*/
}Arguments
- EndDelegate func - Callback function with the following signature:
void EndDelegate()
Return value
ID of the last added fetch end callback, if the callback was added successfully; otherwise, null. This ID can be used to remove this callback when necessary.bool RemoveEndCallback ( IntPtr id ) #
Removes the specified callback from the list of file fetch end callbacks.Arguments
- IntPtr id - End callback ID obtained when adding it.
Return value
True if the fetch end callback with the given ID was removed successfully; otherwise false.void ClearEndCallback ( ) #
Clears all added fetch end callbacks.Last update:
2020-07-31
Help improve this article
Was this article helpful?
(or select a word/phrase and press Ctrl+Enter)