🚀 go-pugleaf

shamelessless@hotmail.com wrote:
>Hello everyone, I have some questions about voodoo ( graphics and 2 )
>Now I don't know too much about the 3d stuff but from a rather
>blunt perspective I can see 3 basic operations.
>
>1- Calculation of the coordinates of the triangle mesh for the
>next frame (this has to be done by the cpu and my guess
>is it is not that computationally intensive).
>2- The triangle setup, warping the triangles and associated textures
>(transforming,
>what ever you call this). this step can be done by voodoo in glide or
>opengl.
>But in d3d the cpu has to handle it.

This is incorrect.  There are two distinct steps here, and you are
confusing them together.

Geometric transformation is the computation of the 3D screen coordinates
from the 3D object coordinates with respect to the viewer's point of view.
This is done by the CPU.  Associated with this typically is lighting
calculations for each vertex of the polygons.  This is also done by the
CPU.  Glide has NO provisions for doing either of these things, but both
D3D and OpenGL do (in the APIs).

I don't know of any graphics chip set you can buy on a card for under
$500 today that has the ability to do either of the above functions.

Following the above operations is triangle setup.  This is the process
where typically a triangle is split into two trapezoids (for conventional
architectures), the coordinates are converted to fixed point, and
several "deltas" are computed to allow the rasterizer to iterate over
all the pixels of the triangles.

Triangle setup is what is done in hardware.  It is also usually not
really part of an API, but rather something that happens "under the
covers".  If a chip does triangle setup, it typically MUST do triangle
setup.  Not doing it is usually not an option.

>3- Rendering, copying textures etc. (done by the 3d card)

Rasterization, texture-mapping, Z-buffering, blending, fogging, etc.
"Rendering" is the term used for the overall process.