# ObjectExternBase Class (CPP)

**Header:** #include <UnigineObjects.h>

**Inherits from:** Base


The base class, from which the [custom user-defined objects](../../../api/library/objects/class.objectextern_cpp.md) are inherited.


## ObjectExternBase Class

---

## template < class Type >

## static addClassID ( int class_id )

Registers the custom object class with a unique class ID.
```cpp
// register the MyObject class
ObjectExternBase::addClassID<MyObject>(1);

```


### Arguments

- *int* **class_id** - Unique class ID.

## int getClassID ( )

Returns a unique class ID.
### Return value

Unique class ID.
## int getCollision ( const Math:: Vec3 & p0 , const Math:: Vec3 & p1 , Vector < int > & OUT_surfaces )

Spatial collision with the bounding box.
### Arguments

- *const  Math::[Vec3](../../../api/library/math/class.vec3_cpp.md) &* **p0** - Coordinates of the start point of the line.
- *const  Math::[Vec3](../../../api/library/math/class.vec3_cpp.md) &* **p1** - Coordinates of the end point of the line.
- *[Vector](../../../api/library/containers/vector/class.vector_cpp.md)< int > &* **OUT_surfaces** - Return array with surface numbers. > **Notice:** This output buffer is to be filled by the Engine as a result of executing the method.

### Return value

Returns **1** if the array of surfaces is not empty.
## int getCollision ( const BoundBox & bb , Vector < int > & OUT_surfaces )

Spatial collision with the bounding box.
### Arguments

- *const [BoundBox](../../../api/library/math/bounds/class.boundbox_cpp.md) &* **bb** - Bounding box.
- *[Vector](../../../api/library/containers/vector/class.vector_cpp.md)< int > &* **OUT_surfaces** - Return array with surface numbers. > **Notice:** This output buffer is to be filled by the Engine as a result of executing the method.

### Return value

Returns **1** if the array of surfaces is not empty.
## int getIntersection ( const Math:: Vec3 & p0 , const Math:: Vec3 & p1 , Math:: Vec3 * OUT_ret_point , Math:: vec3 * OUT_ret_normal , Math:: vec4 * OUT_ret_texcoord , int * OUT_ret_index , int * OUT_ret_instance , int surface )

Returns a value indicating that the line intersects the object surface.
### Arguments

- *const  Math::[Vec3](../../../api/library/math/class.vec3_cpp.md) &* **p0** - Coordinates of the start point of the line.
- *const  Math::[Vec3](../../../api/library/math/class.vec3_cpp.md) &* **p1** - Coordinates of the end point of the line.
- *Math::[Vec3](../../../api/library/math/class.vec3_cpp.md) ** **OUT_ret_point** - Intersection point coordinates. Pass NULL if this parameter is not required. > **Notice:** This output buffer is to be filled by the Engine as a result of executing the method.
- *Math::[vec3](../../../api/library/math/class.vec3_cpp.md) ** **OUT_ret_normal** - Intersection normal vector. Pass NULL if this parameter is not required. > **Notice:** This output buffer is to be filled by the Engine as a result of executing the method.
- *Math::[vec4](../../../api/library/math/class.vec4_cpp.md) ** **OUT_ret_texcoord** - Intersection texture coordinates. Pass NULL if this parameter is not required. > **Notice:** This output buffer is to be filled by the Engine as a result of executing the method.
- *int ** **OUT_ret_index** - Intersected triangle number. Pass NULL if this parameter is not required. > **Notice:** This output buffer is to be filled by the Engine as a result of executing the method.
- *int ** **OUT_ret_instance** - Intersected instance number. Pass NULL if this parameter is not required. > **Notice:** This output buffer is to be filled by the Engine as a result of executing the method.
- *int* **surface** - Surface number.

### Return value

Returns **1** if the intersection occurs.
## Ptr < Node > getNode ( ) const

Returns the Node smart pointer.
### Return value

Node smart pointer.
## int getNumSurfaces ( )

Returns the number of object surfaces.
### Return value

The number of object surfaces.
## int getNumTriangles ( int surface )

Returns the number of triangles.
### Arguments

- *int* **surface** - Surface number.

### Return value

Returns the number of triangles.
## Ptr < Object > getObject ( ) const

Returns the Object smart pointer.
### Return value

Object smart pointer.
## Ptr < ObjectExtern > getObjectExtern ( ) const

Returns the ObjectExtern smart pointer.
### Return value

ObjectExtern smart pointer.
## int getOrder ( const Math:: Vec3 & camera , int surface )

Returns the rendering order with respect to the camera position.
### Arguments

- *const  Math::[Vec3](../../../api/library/math/class.vec3_cpp.md) &* **camera** - World camera position.
- *int* **surface** - Surface number.

### Return value

Surface rendering order.
## int getRandomPoint ( Math:: vec3 & ret_point , Math:: vec3 & ret_normal , Math:: vec3 & ret_velocity , int surface )

Returns a random point from a surface.
### Arguments

- *Math::[vec3](../../../api/library/math/class.vec3_cpp.md) &* **ret_point** - Random point coordinates.
- *Math::[vec3](../../../api/library/math/class.vec3_cpp.md) &* **ret_normal** - Random normal vector.
- *Math::[vec3](../../../api/library/math/class.vec3_cpp.md) &* **ret_velocity** - Random velocity vector.
- *int* **surface** - Surface number.

### Return value

Returns **1** if the random point is valid.
## int getResource ( int surface )

Returns the unique render resource identifier.
### Arguments

- *int* **surface** - Surface number.

### Return value

Surface resource identifier.
## int getSequence ( const Math:: Vec3 & camera , int surface )

Returns the rendering sequence with respect to the camera position.
### Arguments

- *const  Math::[Vec3](../../../api/library/math/class.vec3_cpp.md) &* **camera** - World camera position.
- *int* **surface** - Surface number.

### Return value

Surface rendering sequence.
## const char * getSurfaceName ( int surface )

Returns the object surface name.
### Arguments

- *int* **surface** - Surface number.

### Return value

Surface name.
## float getTransparentDistance ( const Math:: Vec3 & camera , int surface )

Returns the transparent rendering distance.
### Arguments

- *const  Math::[Vec3](../../../api/library/math/class.vec3_cpp.md) &* **camera** - World camera position.
- *int* **surface** - Surface number.

### Return value

Surface rendering distance.
## void create ( int surface )

Renders a create function.
### Arguments

- *int* **surface** - Surface number.

## int findSurface ( const char * name )

Returns the number of the object surface by its name.
### Arguments

- *const char ** **name** - Surface name.

### Return value

Surface number.
## bool hasCreate ( )

Returns a value indicating that the object has a create function.
### Return value

true if the object has a create function; otherwise, false.
## bool hasLods ( )

Returns a value indicating if the object has LODs.
### Return value

true if the object has surface LODs; otherwise, false.
## bool hasRender ( )

Returns a value indicating that the object has a render function.
### Return value

true if the object has a render function; otherwise, false.
## bool hasShadow ( )

Returns a value indicating that the object has a shadow function.
### Return value

true if the object has a shadow function; otherwise, false.
## int loadWorld ( const Ptr < Xml > & xml )

Loads an object state from the Xml.
### Arguments

- *const [Ptr](../../../api/library/common/class.ptr_cpp.md)<[Xml](../../../api/library/common/class.xml_cpp.md)> &* **xml** - Xml smart pointer.

### Return value

Returns **1** if the object state was successfully loaded; otherwise, **0** is returned.
## void preRender ( float ifps )

Pre-render function, i.e. after the *update()* and before the *render()* function. This method can be used to make necessary preparations for rendering (e.g. prepare a texture) after the *update()*.
### Arguments

- *float* **ifps** - Inverse FPS value.

## void render ( Render::PASS pass , int surface )

Renders the render function.
### Arguments

- *[Render::PASS](../../../api/library/rendering/class.render_cpp.md#PASS)* **pass** - Rendering pass.
- *int* **surface** - Surface number.

## void renderHandler ( )

Renders the handler.
## void renderShadow ( Render::PASS pass , int surface )

Renders render function.
### Arguments

- *[Render::PASS](../../../api/library/rendering/class.render_cpp.md#PASS)* **pass** - Rendering pass.
- *int* **surface** - Surface number.

## void renderVisualizer ( )

Renders the visualizer.
> **Notice:** You should enable the engine visualizer by the **show_visualizer 1** console command.


## void resizeSurfaces ( ) const

Resizes all of the object surfaces.
## int saveState ( const Ptr < Stream > & stream )

Saves an object state into the stream.
Saving into the stream requires creating a blob to save into. To restore the saved state the [restoreState()](#restoreState_Stream_int) method is used:


```cpp
// initialize a node and set its state
//...//

// save state
BlobPtr blob_state = Blob::create();
object->saveState(blob_state);

// change state
//...//

// restore state
blob_state->seekSet(0);				// returning the carriage to the start of the blob
object->restoreState(blob_state);

```


### Arguments

- *const [Ptr](../../../api/library/common/class.ptr_cpp.md)<[Stream](../../../api/library/common/class.stream_cpp.md)> &* **stream** - Stream smart pointer.

### Return value

Returns **1** if the object state was successfully saved into the stream; otherwise, **0** is returned.
## int restoreState ( const Ptr < Stream > & stream )

Restores an object state from the stream.
Restoring from the stream requires creating a blob to save into and saving the state using the [saveState()](#saveState_Stream_int) method:


```cpp
// initialize a node and set its state
//...//

// save state
BlobPtr blob_state = Blob::create();
object->saveState(blob_state);

// change state
//...//

// restore state
blob_state->seekSet(0);				// returning the carriage to the start of the blob
object->restoreState(blob_state);

```


### Arguments

- *const [Ptr](../../../api/library/common/class.ptr_cpp.md)<[Stream](../../../api/library/common/class.stream_cpp.md)> &* **stream** - Stream smart pointer.

### Return value

Returns **1** if the object state was successfully restored from the stream; otherwise, **0** is returned.
## int saveWorld ( const Ptr < Xml > & xml )

Saves an object state into the Xml.
### Arguments

- *const [Ptr](../../../api/library/common/class.ptr_cpp.md)<[Xml](../../../api/library/common/class.xml_cpp.md)> &* **xml** - Xml smart pointer.

### Return value

Returns **1** if the object state was successfully saved; otherwise, **0** is returned.
## void update ( float ifps )

Update function.
### Arguments

- *float* **ifps** - Inverse FPS value.

## void updateEnabled ( )

Updates enabled.
## void updateEnabled ( int surface )

Updates enabled.
### Arguments

- *int* **surface** - Surface number.

## void updateSurfaces ( ) const

Updates all of the object surfaces.
## void updateTransform ( )

Updates transformation.
## void setUpdateDistanceLimit ( float distance )

Sets the distance from the camera within which the object should be updated.
### Arguments

- *float* **distance** - Distance from the camera within which the object should be updated (in units).

## float getUpdateDistanceLimit ( )

Returns the distance from the camera within which the object should be updated.
### Return value

Distance from the camera within which the object should be updated (in units).
## void setForceUpdate ( bool enabled )

Sets a value indicating if the object should be constantly updated each frame, regardless of the [update distance](#setUpdateDistanceLimit_float_void).
### Arguments

- *bool* **enabled** - true to enable forced updating for the object; false - to disable forced updating and take the [update distance](#setUpdateDistanceLimit_float_void) into account.

## bool isForceUpdate ( )

Returns a value indicating if the object should be constantly updated each frame, regardless of the [update distance](#setUpdateDistanceLimit_float_void).
### Return value

true if the object is constantly updated each frame; otherwise, false