Atari - Pole Position

[Scott_Bro]

I need help working out the road scrolling.
If I scroll the image it's fine but if I want to do it with code...
It's reverse and I can't figure out what to write.
Can someone please help me fix this? please, and thanks!

Scottie B

[kevin]

I've never thought much about making a classic racer,  so i'm not  sure of the best methods.  On retro hardware, they're using raster splits to display the track and do things like the scrolling the raster bars.   In really early ones I'd doubt there's any perspective calcs at all..

as for your problem, sounds like a order of operations issue.  Will have a look see later
   

[stevmjon]

just letting you know, i have spent a few hours going through the code to figure out how it works. i am now playing with values and i now see what you mean.
if you go in the positive z direction it doesn't scroll properly, but when you travel in the neg z direction it scrolls fine.

i am getting an idea what is causing this, but it is 3am for me, so i will continue tomorrow.

if you do figure it out, can you make a post to let us know.

  steve


EDIT: oops, i didn't see kevs post above. i will still keep looking though. 2 heads are better than one...

[stevmjon]

i figured it out and added zip file below. yay.

i added edits in such a way to make the least changes to your code, so it is better to travel in the neg z direction, at least for the uv mapping.
you can use variables so the car appears to go in a pos z direction with pos znear and zfar values so you can add trigger events for corners etc...

good luck, i hope this helps you.

  stevmjon

[kevin]

  Steve,


    mind posting a screen shot as i'm getting a blank screen here.



   Edit: it's just my system doesn't like rendering text to locked buffer..  pull out the locks and it works as expected


Unrelated Videos:

   Just ran into this video of Eliminator on the Amiga from 1989..  Pretty cool
   

    Sanity - Arte -= Amiga 50fps =-  (released 1993)
    This has some of the best tunnel/road effects produced on the platform.   
   

[Scott_Bro]

Thanks, I'll have a look soon.
I know this is a little out of the subject but well worth mentioning!


Here's a monumental idea. And I am very willing to put hard work into it.
I'm using motion tracking to target videos and importing data into app where I can make shooting in real-time accurate.
I have a working proto-type written in app game kit though I'm still experimenting.
I seem to be having trouble finding videos that work well with it. I have some ideas for working around a few things like...
Changes in gameplay being captured as pre-rendered animations taking out of the footage based on what I'm tracking.
Currently I have a green screen of a dino walking and I'm tracking his eye with markers pre-recorded and then re-playing video with app.
while box collision is in full moving and working for interactions but...
I would like full video with no green screen. It' would be the same thing. but can't find clear videos like duck hunting with high detail.
This should make for some very fun games!!! I just need help out there if I have any takers???

Peace, and thanks again.
Scottie B

[Scott_Bro]

Here is the updated road.
It now includes hills with up and down action.

I seem to be having trouble figuring out how to do signs and cars.
I know it's z-scaled sprites but I have not got anything to look good enough yet.
Can someone please take a look at it and see if they can help? Kevin even, maybe...
This is now plenty of sprites in from the games pole position one and two in the images files.
Ripped and ready to go!

Thanks,
Scottie B

[kevin]

  I don't know for how your going about this, but for each depth you'd compute the ground height as well as the height of the highest  span of foreground height.   sprites need to be scaled proportional and placed at the required gouond height for the depth in back to front order.  To avoid overdraw you'll need to clip sprites to the ground, so  far sprite thats bellow the highest span of foreground is hidden, the same goes for ground rows.

[kevin]

Take a look at Z Depth Perspective For Sprites

[kevin]

  Not entirely in the same theme, but well within the same ball park with an added twist..  never seen this arcade before.