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Gets Matrix4x4 that can be used to convert 3D coordinates to 2D view (screen) coordinates.
If the method returns true, then the worldToViewMatrix was set; if false is returned than the matrix cannot be calculated.
Namespace: Ab4d.SharpEngine
Assembly: Ab4d.SharpEngine (in Ab4d.SharpEngine.dll) Version: 3.0.9208+3b2441d6a11f923f2600f40f4296bdc3d8b46035
SyntaxC#
public bool GetWorldToViewMatrix( out Matrix4x4? worldToViewMatrix, bool updateIfDirty = true )
Parameters
- worldToViewMatrix Matrix4x4
- reference to Matrix4x4
- updateIfDirty Boolean (Optional)
- when true (by default) then the Update(Boolean) method is called if the camera was changed after the last matrices were calculated; when false the current values are returned (can be outdated)
Return Value
Booleantrue if worldToViewMatrix was set; false if the matrix cannot be calculated
RemarksGetWorldToViewMatrix gets Matrix4x4 that can be used to convert 3D coordinates to 2D viewport coordinates.
If the method returns true, then the worldToViewMatrix was set; if false is returned than the matrix cannot be calculated (for example when MatrixCamera is used and the matrix cannot be inverted).
Important:
To calculate the view (screen) coordinates of a 3D point you need to convert the Point3D to Point4D, multiply it with worldToViewportMatrix and then divide the X and Y coordinate with W value from Point4D struct.
The following code shows that:
C#
Vector2 screenPoint; bool isWorldToViewMatrixValid = sceneView.GetWorldToViewMatrix(out var worldToViewMatrix, updateIfDirty: true); if (isWorldToViewMatrixValid) { var screenPoint4 = Vector4.Transform(new Vector4(point3D.X, point3D.Y, point3D.Z, 1), worldToViewMatrix); // Get screen position - perform perspective division (divide by W) if (screenPoint4.W > 0 || (screenPoint4.W != 0 && myCamera.ProjectionType == ProjectionTypes.Orthographic)) // if W < 0 then point is behind the camera; this is only allowed for Orthographic camera { if (adjustByDpiScale) screenPoint = new Vector2(screenPoint4.X / (screenPoint4.W * sceneView.DpiScaleX), screenPoint4.Y / (screenPoint4.W * sceneView.DpiScaleY)); else screenPoint = new Vector2(screenPoint4.X / screenPoint4.W, screenPoint4.Y / screenPoint4.W); } else { screenPoint = new Vector2(float.NaN, float.NaN); } } else { screenPoint = new Vector2(float.NaN, float.NaN); }
See Also