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The C modest god

Does the world matrix change the view matrix?

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The WORLD, VIEW, and PROJECTION matrices can be thought of as three distinct things. The WORLD matrix transforms things in world space, "I move this box onto this table". The VIEW matrix transforms things to camera space. "I (the viewer) am looking down at the table", and the PROJECTION matrix transforms things into screen space "This point on the table maps to this x,y coordinate on my screen".

Due to the magic of Matrix multiplication, all three are multiplied together, and then the resulting matrix can be used to transform all geometry from it''s local space into screen space. When dealing with things in 3-D space however, you mostly want to stick with mucking with the WORLD matrix. Only change the VIEW matrix if you want to change your view, and only change the PROJECTION matrix if you want to change how you are mapping your coordinates to screen space (perspective or orthographic projections, changing your FOV, ect...)

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1. What NerdBoy80 said.

2. **Internally** D3D does hold other matrices which are built from the publically exposed ones. These internal matrices get rebuilt when one of the external matrices (WORLD, VIEW, PROJECTION) it''s formed from changes.

3. The OP may be getting confused due to OpenGL having a matrix called "MODELVIEW" which is simply a concatenated WORLD and VIEW matrix.

--
Simon O''Connor
3D Game Programmer &
Microsoft DirectX MVP

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