RAMRACER TECHNICAL SPECIFICATION

Target machine minimum specification
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PC 486
The game will include options to reduce the detail levels.
For example -
	Light sourcing can be turned off.
	Texture maps can be turned off in the distance.
	Perspective texture mapping can be turned off.
	Reduced screen size.
	Fewer polygons can be displayed in the distance.



Sound cards to be supported
___________________________

All sound cards from the minimum specification should be supported.
However, ARC will need assistance in obtaining drivers for some
of the devices.



Screen resolutions and colours supported
________________________________________

The standard game will run in normal 256 colour VGA.
There MAY be an option to run in 256 colour SVGA, but only for the
very fast machines.



Maximum number of polygons in 3D engine
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This is difficult to quantify because it depends on a multitude of factors.
These are -
	Machine speed.
	Video card speed.
	Polygon size, mapping type, lighting, arrangement, etc.


To help with this, we present some figures representing the number
of polygons per second for various polygon types. These figures were
obtained from the 3D engine generating a reasonably complex scene made
from a variation of large and small polygons, so note that there is more
than just polygon filling in operation here.

Polygons are mapped as either triangles or quadrilaterals.

-----------------------------------------------------
			Polygons	Vertices
			per second	per second
-----------------------------------------------------
Textured polygon	7000		9200
No shading

Textured polygon	6000		8000
Flat shaded

Textured polygon	5100		6800
Gouraud shading
-----------------------------------------------------
Non textured polygon	11700		15600
No shading

Non textured polygon	10500		14000
Flat shaded

Non textured polygon	7800		10400
Gouraud shading
-----------------------------------------------------



Maximum number of moving objects in 3D
______________________________________

These require a rotation and translation for each vertex in every object.
At worst, this amounts to 12 multiplies per vertex per object.
So accordingly, the more complicated an object, the fewer can be transformed
to keep the game speed up.

The maximum number of moving objects has not yet been investigated.
However, it can be seen from the design specification that not many objects
transform anyway. Apart from the cars, catapults, bumpers, track sections
and some hazards move. Many of these do not need to rotate, hence saving
computation time.

If using rotations with light sourcing, an extra consideration will be the
rotation of the surface normals, and for gouraud shading, the vertex normals.

Note that transformations do not necessarily occur for each object in
every frame. The transformations can also be connected to the frame rate
so that if the frame rate drops, the transformations will take on greater
steps.



Shading and image mapping supported
___________________________________

These methods apply to both triangles and quadrilaterals.

Non textured
	No shading
	Flat shading
	Gouraud shading

Textured
	Transparent
	No shading
	Flat shading
	Gouraud shading

The following methods will also be supported -

Polygon outline
Line drawing
Perspective texture mapping



The polygon fill routines are reasonably well optimised. Drawing to the
screen is done horizontally, line by line down the screen. No pixels on
the polygon are overwritten.

The horizontal fills for every polygon mapping type are written in assembly
language and are hand optimised.  Speedups are now being looked at in other
areas since the inner loops are nearly as fast as they can go.  Wherever
possible, data is copied in double words (for non-textured polygons) and the
optimisations cater for pipelining considerations.