Picker
Picker object used to select mesh instances from screen coordinates.
Summary
Properties
| height | Height of the pick buffer in pixels (read-only). |
| renderTarget | The render target used by the picker internally (read-only). |
| width | Width of the pick buffer in pixels (read-only). |
Methods
| getSelection | Return the list of mesh instances selected by the specified rectangle in the previously prepared pick buffer. |
| prepare | Primes the pick buffer with a rendering of the specified models from the point of view of the supplied camera. |
| resize | Sets the resolution of the pick buffer. |
Details
Constructor
Picker(app, width, height)
Create a new Picker instance.
Parameters
| app | AppBase | The application managing this picker instance. |
| width | number | The width of the pick buffer in pixels. |
| height | number | The height of the pick buffer in pixels. |
Properties
Methods
getSelection(x, y, [width], [height])
Return the list of mesh instances selected by the specified rectangle in the previously prepared pick buffer.The rectangle using top-left coordinate system.
// Get the selection at the point (10,20)
const selection = picker.getSelection(10, 20);// Get all models in rectangle with corners at (10,20) and (20,40)
const selection = picker.getSelection(10, 20, 10, 20);Parameters
| x | number | The left edge of the rectangle. |
| y | number | The top edge of the rectangle. |
| width | number | The width of the rectangle. |
| height | number | The height of the rectangle. |
Returns
MeshInstance[]An array of mesh instances that are in the selection.
prepare(camera, scene, [layers])
Primes the pick buffer with a rendering of the specified models from the point of view of the supplied camera. Once the pick buffer has been prepared, Picker#getSelection can be called multiple times on the same picker object. Therefore, if the models or camera do not change in any way, Picker#prepare does not need to be called again.
Parameters
| camera | CameraComponent | The camera component used to render the scene. |
| scene | Scene | The scene containing the pickable mesh instances. |
| layers | Layer[] | Layers from which objects will be picked. If not supplied, all layers of the specified camera will be used. |
resize(width, height)
Sets the resolution of the pick buffer. The pick buffer resolution does not need to match the resolution of the corresponding frame buffer use for general rendering of the 3D scene. However, the lower the resolution of the pick buffer, the less accurate the selection results returned by Picker#getSelection. On the other hand, smaller pick buffers will yield greater performance, so there is a trade off.
Parameters
| width | number | The width of the pick buffer in pixels. |
| height | number | The height of the pick buffer in pixels. |