Jump to content
  • Advertisement
Sign in to follow this  

world <-> screen convert

This topic is 981 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

XMMATRIX ViewProj = _view() * _projection();
XMVECTOR pointInWorld  = XMVector3Transform(worldPoint, ViewProj);

	float x = ((XMVectorGetX(pointInWorld) + 1.0f) / 2.0f) *_width;
	float y = ((-XMVectorGetY(pointInWorld) + 1.0f) / 2.0f) *_height;

XMVECTOR pointInScreen = DirectX::XMVectorSet(x, y, 0.0f, 0.0f); // works fine

	float xx = (((2.0f * x) / _width) - 1.0f);
	float yy = -(((2.0f * y) / _height) - 1.0f);
	float zz = DirectX::XMVectorGetZ(pointInWorld);

	XMMATRIX invView = XMMatrixInverse(NULL, ViewProj);
	XMVECTOR mousePos = XMVectorSet(xx, yy, zz, 1.0f);
	mousePos = XMVector3Transform(mousePosition, invView); // incorrect

Hi, i am trying to figure out why i cannot accurately convert between world and screen coordinates. The code above takes a point in world space and converts it into a screen position (). This seems to work fine, but when i do the opposite to get the original world coordinate, the result is wrong. The x coordinate is usually close but the y and z are tottaly off. Anyone care to explain this to me? 

Share this post

Link to post
Share on other sites
Sign in to follow this  

  • Advertisement

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!