Post by dark on Jan 20, 2017 0:39:55 GMT
From an old thread from 1994
groups.google.com/forum/#!topic/rec.games.video.advocacy/Jojzp1BxduQ
I think this technique resulted in Crash n Burn being able to have the insane draw distances it does without significant pop in - something that could not have occurred if they let you have more control over your car (e.g., being able to go backwards or crash and shift the camera view 90+ degrees.), a criticism of the game by folks at the time and now. Needless to say, it seems Crash n Burn is not pre-rendered FMV a la Megarace as some folks still believe.
groups.google.com/forum/#!topic/rec.games.video.advocacy/Jojzp1BxduQ
[Begin]
From: Gregg A Tavares
To: Nicholas Albright
Sub: C&B
Well,
I probably shouldn't say anything but what the heck. The track is being
pulled off the CD. Originally the entire track was in memory but when the
enemies cars were added the frame rate went all the way down to 5fps. The
solution was to write a tool that would, for each view of the track, remove
all the polygons that are not seen. Since you can move left and right and
up and down (cockpit vs 3rd person) nothing is 'pre-calculated'
Gregg
=END=
[End]
I then asked him to clarify a few points, as to exactly was happening.
Below is his response.
[Begin]
From: Gregg A Tavares
To: Nicholas Albright
Sub: C&B clarifications. = )
Okay, le me C.
The entire track is still in memory. The track consists of tons-o-polygons.
Far too many for any machine to display in real-time. On part of displaying
something in 3D is figuring out which parts you can see and which parts you
can't. For example, if you are driving down a race track and you are
looking forward you can't see behind you therefore you don't want to draw
the stuff behind you on the screen. So, you do some math to tell you what
parts of your 3D world you can actually see. This takes alot of time. In
fact it is probably this single biggest problem with anything that works in
3D. All programs deal with this in different ways. Flight Simulator does
it while it's running. It keeps a list of all the things you can see and as
you fly around it adds or removes things. To see it in action, fly in skew
mode and skew really fast and then stop. You will see different 3D parts
pop in one at a time as the program finds new things that are now in your
view.
On CnB we wrote a program that would 'drive' down the track and for each
section of the track it makes a list of all the parts that can actually be
seen. These 'lists of visible parts' are then stored in the CD and as you
drive down the track the 'list' for the part of the track you are currently
on is loaded. This makes it run faster because we don't have to do all the
calculations for which things are visible while you are racing.
From: Gregg A Tavares
To: Nicholas Albright
Sub: C&B
Well,
I probably shouldn't say anything but what the heck. The track is being
pulled off the CD. Originally the entire track was in memory but when the
enemies cars were added the frame rate went all the way down to 5fps. The
solution was to write a tool that would, for each view of the track, remove
all the polygons that are not seen. Since you can move left and right and
up and down (cockpit vs 3rd person) nothing is 'pre-calculated'
Gregg
=END=
[End]
I then asked him to clarify a few points, as to exactly was happening.
Below is his response.
[Begin]
From: Gregg A Tavares
To: Nicholas Albright
Sub: C&B clarifications. = )
Okay, le me C.
The entire track is still in memory. The track consists of tons-o-polygons.
Far too many for any machine to display in real-time. On part of displaying
something in 3D is figuring out which parts you can see and which parts you
can't. For example, if you are driving down a race track and you are
looking forward you can't see behind you therefore you don't want to draw
the stuff behind you on the screen. So, you do some math to tell you what
parts of your 3D world you can actually see. This takes alot of time. In
fact it is probably this single biggest problem with anything that works in
3D. All programs deal with this in different ways. Flight Simulator does
it while it's running. It keeps a list of all the things you can see and as
you fly around it adds or removes things. To see it in action, fly in skew
mode and skew really fast and then stop. You will see different 3D parts
pop in one at a time as the program finds new things that are now in your
view.
On CnB we wrote a program that would 'drive' down the track and for each
section of the track it makes a list of all the parts that can actually be
seen. These 'lists of visible parts' are then stored in the CD and as you
drive down the track the 'list' for the part of the track you are currently
on is loaded. This makes it run faster because we don't have to do all the
calculations for which things are visible while you are racing.
I think this technique resulted in Crash n Burn being able to have the insane draw distances it does without significant pop in - something that could not have occurred if they let you have more control over your car (e.g., being able to go backwards or crash and shift the camera view 90+ degrees.), a criticism of the game by folks at the time and now. Needless to say, it seems Crash n Burn is not pre-rendered FMV a la Megarace as some folks still believe.