Questions tagged [directxmath]

DirectXMath API provides common linear algebra and graphics math operations to DirectX applications

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How to clip cut-off using different frustrum than that of original camera? How to cut plane by pyramid shape?

SOURCE : http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2012/10/Mitchell_LightShafts.pdf This process is part of creating light draft effect. And I am suggested to do the described process in ...
157 views

How can I get projected coordinates of vertex on screen

I want to check picking for faces and for that I need projected X Y coordinates of my vertexes in -1 to 1 range: For that I multiply my vertex array with matrices and then get projected triangle ...
514 views

2d Scale width and height based on distance

I'm drawing a health bar on top of each player. I transform 3d position to 2d. I would like to draw it smaller when distance increases. Any simple math for that? Let's say bar width is 30 and height ...
3k views

Calculate matrix transformation components separately

It is possible to calculate the translation, rotation and scale that were used to build a matrix? I mean if I have a matrix M can I calculate the rotation, scale, ...
2k views

How do I correctly multiply an XMMATRIX by a scalar?

Using DirectXMath and its XMMATRIX structure in C++ and Direct X 11, how does one multiply that matrix structure by a single float scalar? I want to implement the ...
244 views

Can I use memcpy() with XMMATRIX?

I.e. can I do this: XMMATRIX dxMat; Matrix myMat; std::memcpy(&myMat, &dxMat, sizeof(XMMATRIX)); std::memcpy(&dxMat, &myMat, sizeof(XMMATRIX)); <...
860 views

How to rotate camera using mouse?

I'm looking for a basic example of rotating camera using the mouse. the only problem is I'm not sure of how to rotating the camera around it target. should i do this by an algorithm or is there a ...
78 views

how to debug calculating tangent space

[][]2 there's problem calculating tangent space and look.... it seems there is no problem with UV code and my shader is 100% no problem. I just copy and pasted tutorial code which works well.. I ...
281 views

Why doesn't TriangleTests::Intersects from DirectXMath work correctly?

I am currently looking through the Introduction to 3D Game Programming with Direct X 11 by Frank Luna and I'm trying to implement the ray-triangle intersections. I already have a ray firing when the ...
93 views

Is there something similar to XMFLOAT2 that has its operators overloaded?

Since XMFLOAT2 is just a structure, I'm sure it does not have operator overloading which is what I need to make things a lot simpler. Is there something like ...
265 views

Copy unaligned XMVECTOR and use the copy?

I know XMVECTOR has to be 16-byte-aligned and therefore shouldn't be a member of a class (unless I ensure the alignment). However, can I do sth like this? ...
60 views

What exactly does XMMatrixPerspective{L,R}H do?

There are generally three functions to create a perspective matrix in DirectXMath, XMMatrixPerspective{L,R}H, ...
376 views

Difference between column- and row vector matrix multiplication (vector transform)

Let's say we have a 4-by-4 matrix A which represents some transformation. We can use this matrix to transform a vector in two ways. ...
37 views

XMMATRIX performance

Dears, I am facing a performance problem when I try to access cell 42 and 43 in XMMATRIX define in DirectXMath.h. The frames dropped by 100 FPS. Here is my code: ...