Unigine.WorldOccluderTerrain Class
| Inherits: | Node |
Terrain occluder introduces a cheaper and more efficient way of handling intersections with terrains. The objects behind the terrain occluder are not sent to the GPU, which saves performance.
Notice
If terrain relief is changed in the runtime, it is not recommended to use the occluder.
Usage
To provide increased performance, terrain occluders should be used wisely.
- A terrain occluder can be a great benefit in case of mountains or complex urban environments.
- If a terrain is flat, occluder can reduce FPS since there are no surfaces that can be culled.
- On the contrary, an occluder is highly effective if there are many objects that are costly to render (they have a lot of polygons and/or heavy shaders). However, these objects should not be too large since if any part of their surface is seen, it cannot be culled.
- When the camera is high above the ground (for example, for flight simulators), an occluder should be disabled. At the same time, when it is near or on the ground (during a takeoff or landing), occluders can be enabled to provide performance gain.
- If terrain relief is changed in the runtime, it is not recommended to use the occluder.
Generation
The terrain occluder is generated based on its downsized height map using cone-step mapping. Generation of an occluder texture is a time-consuming operation that should be done only once rather than each time on world load.
To set a texture for WorldOccluderTerrain in real-time, use the following steps:
- Set a height map texture (in R8, R16 or RG8 format) via setHeightsImageName() . Cone-step mapping will be calculated and a new image (inRGB8 format) will be generated. It contains all data necessary to perform occlusion.
- Get newly generated occluder image (RGB8) via getHeightsImage() .
- Save this occluder image (RGB8) to disk with same name.
WorldOccluderTerrain Class
Members
static WorldOccluderTerrain(vec3 size)
Constructor. Creates a new terrain occluder of the specified size.Arguments
- vec3 size - Size of the terrain occluder in units.
WorldOccluderTerrain cast(Node node)
Casts a WorldOccluderTerrain out of the Node instance.Arguments
- Node node - Node instance.
Return value
WorldOccluderTerrain instance.void setDistance(float distance)
Sets the distance for disabling terrain occluder.Arguments
- float distance - Distance in units. If a negative value is provided, 0 will be used instead.
float getDistance()
Returns the current distance for disabling terrain occluder.Return value
Distance in units.Image getHeightsImage()
Returns the height map image that repeats terrain heights.Return value
Height map image.int setHeightsImageName(string name)
Sets the name of the height map that repeats terrain heights. The height map can be smaller in size compared to terrain's one. It will be automatically converted into the RGB8 format.Arguments
- string name - Height map name.
Return value
1 if the height map was successfully loaded; otherwise, 0.string getHeightsImageName()
Returns the name of the height map that repeats terrain heights.Return value
The name of the height map.void setRadius(float radius)
Radius of ray tracing to perform occlusion. The radius is counted off starting from the camera.Arguments
- float radius - Radius of occlusion in units.
float getRadius()
Returns the current ray tracing radius to perform occlusion.Return value
Radius of occlusion in units.void setSize(vec3 size)
Sets the dimensions of the terrain occluder.Arguments
- vec3 size - Size of the terrain occluder in units. If a negative value is provided, vec3(0.0f) will be used instead.
vec3 getSize()
Returns the current dimensions of the terrain occluder.Return value
Size of the terrain occluder in units.int type()
Returns the type of the node.Return value
World type identifier.Last update: 2018-08-10
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