Jump to content

  • Log In with Google      Sign In   
  • Create Account

#Actualtonemgub

Posted 16 October 2013 - 10:38 AM

The terms "local coordinate sytem" and "global coordinate system" are misnomers. In reality, there is only one coordinate system (that is used in computer graphics, anyway): the carthesian coordinate system. The "local" and "global" terms are usually used only to differentiate between coordinates before a certain transformation is applied to them (the "local coordinates") and the same, but already transformed coordinates (the "global coordinates"). From my experience, these terms are very rarely used in technical documentation, and when they are, they are used informally.

 

The transformation of one set of coordinates (a position vector) to another is done using a transformation matrix. The amount of rotation applied is held in this matrix, along with translation and scaling amounts. So if you have this matrix, you can get the rotation/translation and scaling amounts from it, using a function like D3DXMatrixDecompose.


#2tonemgub

Posted 16 October 2013 - 10:35 AM

The terms "local coordinate sytem" and "global coordinate system" are misnomers. In reality, there is only one coordinate system (that is used in computer graphics, anyway): the carthesian coordinate system. The "local" and "global" terms are usually used only to differentiate between coordinates before a certain transformation is applied to them (the "local coordinates") and the same, but already transformed coordinates (the "global coordinates"). From my experience, these terms are very rarely used in technical documentation, and when they are, they are used informally.

 

The transformation of one coordinate to another is done using a transformation matrix. The amount of rotation applied is held in this matrix, along with translation and scaling amounts. So if you have this matrix, you can get the rotation/translation and scaling amounts from it, using a function like D3DXMatrixDecompose.


#1tonemgub

Posted 16 October 2013 - 10:34 AM

The terms "local coordinate sytem" and "global coordinate system" are misnomers. In reality, there is only one coordinate system (that is used in computer graphics, anyway): the carthesian coordinate system. The "local" and "global" terms are usually used only to differentiate between coordinates before a certain transformation is applied to them (the "local coordinates") and the same, but already transformed coordinates (the "global coordinates"). From my experience, these terms are very rarely used in technical documentation, and when they are, they are used informally.

 

The transformation of one coordinate to another is done using a transformation matrix. The amount of rotation applied is held in this matrix, along with translation and scaling. So if you have this matrix, you can get the rotation/translation and scaling amounts from it, using a function like D3DXMatrixDecompose.


PARTNERS