XMVector3Unproject function (directxmath.h)

Article
02/22/2024

Projects a 3D vector from screen space into object space.

Syntax

XMVECTOR XM_CALLCONV XMVector3Unproject(
  [in] FXMVECTOR V,
  [in] float     ViewportX,
  [in] float     ViewportY,
  [in] float     ViewportWidth,
  [in] float     ViewportHeight,
  [in] float     ViewportMinZ,
  [in] float     ViewportMaxZ,
  [in] FXMMATRIX Projection,
  [in] CXMMATRIX View,
  [in] CXMMATRIX World
) noexcept;

Parameters

[in] V

3D vector in screen space that will be projected into object space. X and Y are in pixels, while Z is 0.0 (at ViewportMinZ) to 1.0 (at ViewportMaxZ).

[in] ViewportX

Pixel coordinate of the upper-left corner of the viewport. Unless you want to render to a subset of the surface, this parameter can be set to 0.

[in] ViewportY

Pixel coordinate of the upper-left corner of the viewport on the render-target surface. Unless you want to render to a subset of the surface, this parameter can be set to 0.

[in] ViewportWidth

Width dimension of the clip volume, in pixels. Unless you are rendering only to a subset of the surface, this parameter should be set to the width dimension of the render-target surface.

[in] ViewportHeight

Height dimension of the clip volume, in pixels. Unless you are rendering only to a subset of the surface, this parameter should be set to the height dimension of the render-target surface.

[in] ViewportMinZ

Together with ViewportMaxZ, value describing the range of depth values into which a scene is to be rendered, the minimum and maximum values of the clip volume. Most applications set this value to 0.0f. Clipping is performed after applying the projection matrix.

[in] ViewportMaxZ

Together with MinZ, value describing the range of depth values into which a scene is to be rendered, the minimum and maximum values of the clip volume. Most applications set this value to 1.0f. Clipping is performed after applying the projection matrix.

[in] Projection

Projection matrix.

[in] View

View matrix.

[in] World

World matrix.

Return value

Returns a vector in object space.

Remarks

The ViewportX, ViewportY, ViewportWidth, and ViewportHeight parameters describe the position and dimensions of the viewport on the render-target surface. Usually, applications render to the entire target surface; when rendering on a 640*480 surface, these parameters should be 0, 0, 640, and 480, respectively. The ViewportMinZ and ViewportMaxZ are typically set to 0.0f and 1.0f but can be set to other values to achieve specific effects.

Platform Requirements

Microsoft Visual Studio 2010 or Microsoft Visual Studio 2012 with the Windows SDK for Windows 8. Supported for Win32 desktop apps, Windows Store apps, and Windows Phone 8 apps.

Requirements

Requirement	Value
Target Platform	Windows
Header	directxmath.h (include DirectXMath.h)

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