For Buggy Boy and others interested in this aspect.

Draw Distances/Frame Rates

Yes, well aware of this.

There are 3 main things that affect frame rates.

1 Draw distances,

2 The 'size' and number of textures, and

3 How many complex cars are changing direction a lot within close/medium draw distances.

I cant do anything about whether you run the big textured/16 bit cars, but I can influence the other two things.

The IOM Mountain Course has so many fast slight twists and turns and so much close to track foliage in many parts until the start of the Mountain, that I can get a lot of the draw distances right down without pop ups appearing in front. I use my PC as a test and have the detail slider half way.

On the Mountain the draw distances have to be much longer but there are far fewer walls and objects to draw.

Let me ask you a question.

Those textures you see in the new screenshot, they look pretty good dont they?

Well they are ALL 4 BIT !!! except the sky. Even the stone wall with the hedge on top with top transparency. They are 1/6 th the size of 16 Bit textures and very frame rate friendly for Voodoo OR Geforce. So who needs 16 bit? especially at racing speeds!!

For example, that asphalt texture is 256 X 256 4 Bit and 32 KB.

An equivalent sized 16 Bit texture would be 192 KB.

Load up an object intensive, all 16 bit track and drive it at speed and all but the fastest machines, eg P4 2.5 fastest GForce 4 will have trouble rendering them and give intermittently poor frame rates or frame rate 'stutter' when there are a lot of AI close at speed.

Frankly, I would have had a much easier time making it in 16 bit but I chose to do the hard yards and convert/paint all my textures back to 4 Bit, to ensure it was very DRIVABLE and SMOOTH looking at speed.

There is a detailed account of my approach to constructing this Course on Page 7 of the Course Guide.

I encourage everyone interested in this track to read the whole thing.

On my Manx TT page {see above link}

Thanks for your interest guys. The only reward I want is for you guys find this Course interesting enough to be still driving it next year.

Buggy Boy


Please take care of the draw distances, as they have such an influence on the frame rate.

I have a P4 1,8 GHz computer and problems with the frame rates of all the latest releases, like WG47, Laguna Seca, Assen and Ring Djursland. Fine tracks, but I don't drive them due to the poor frame rate.

Adrian D

I spent most septembers camped in the field next to Bottom of Barregarrow for the Manx GP back in the 70s

If this is made as narrow as RL then the Brab will thrash the Lotus for sure

The Nurburgring was always my favorite track from the first day I drove on it in an Alfetta in 1951.(Fangio)

For Adrian

Yes....Its ALL narrow

Narrow....but Dangerous!!

Yep...the Braby is great around here.

You need setups that tell you where the rear end is at all times. Small margins for error and plenty of bumps.

My Default setups will do this for you.


Hi Jim
You've had to cut down this course because of the constraints of GPL..
It just occurred to me ( yes I am slow in more ways than one) that NR2003 may not have that track length constraint. I may be wrong here ...
I know ( and totally agree) that the GPL is the priority, but i just wondered if you had plans in future to stretch that track to its full length

Great work Jim.. looking forward to this one big time !

Yes, I would like to have a crack at the real 63 km length, but if it meant that the only cars you could race on it were those great big lumps of lead that cant turn corners, just a long big radius banked bend, what a travesty that would be.

My personal view is that Nascar 'cars' are best left where they belong, and where you can have some reasonable racing with them, on essentially round 'tracks' [ if you can really call them tracks ] that are banked so much that they dont 'fall off'

Just MHO of course.

Simon 67
on your website you say:

"Unfortunately, GPL doesnt like tracks longer than about 25 km. Over this length the AI dont work and other very evil things start happening.

So sadly, building the full length 63 km Manx TT Mountain course for offline racing is not feasible."

so in this case is it possible to build it for on-line racing or without ai?
or are there still too many problems to overcome even without ai?

Simon, this question comes up periodically and there is no real definitive answer that I know of.

This is what I know.

1 I tried various length test tracks from 24 to 63 km and couldnt get anything over 29 km to load. When that track loaded my car just bounced slowly on the surface up and down about 10 metres vertically, completely undrivable. AI also didnt work.They drive for a bit then stop and dissapear. Thats why I say, weird things start to happen.

2 Test tracks were all made within a reasonable 'world' size ie they went out straight for 10k then doubled back, that sort of thing. I did get AI to work on one 26k test track but that had only 4 corners.

On a complicated layout like the IOM with 162 corners, the added complexity seems to limit length a bit more. eg at one stage I tried to put a extra few hundred metres into my 24.2 km IOM track at which point it refused to load, so I had to go back to my earlier GTK.

3 I have a copy of the AVUS 'long' beta which is 29 km I think and it seems drivable for the player [ although I did less than 1 lap ]but the AI dont work on it [ stop then dissapear] I think this track only works up to a point because it has only two corners. BTW and no disrespect to the maker intended, it would have to be the most excruciatingly boring thing I have exposed myself to in years!!

4 Mark Beckman thinks there is a way to make a longer than 25km track without AI but I have not pestered him about it, he has his hands full with Titans.

5 There is indirect verification in the fact that the longer GPL tracks wont convert to the Nascar Papy games. I therefore think that the game code somehow imposes the restriction and the only reason I can do a 24 km circuit is because Papy had to accomodate a track of 23km [The Ring] in GPL

6 The full 63 km around the Mountain Circuit even as a time trial without AI would be fun but on line racing would probably not be as much fun as some people think, because the way the track drives and the extreme length would mean you would never see your on line competitors, not even to lap them!! Think about on line driving at the Ring, then triple the isolation of that and you'll get what I mean.

7 I have three DUKE DVD's of the IOM and a DUKE videotape and have the advantage of really good on bike and stop frame footage of all the real course. I have done my best and think I have captured the true FEEL of the long course in my shorter version. Even the track map looks uncannily like the real map. And its certainly fun to race the AI from the back of the grid and try to beat the field in a 3 lap Int Short race. If this were 63 km then that race would be 1 lap!

8 Finally, starting this project I ran the risk of some people dismissing it as just another fantasy track because it isnt the correct length. I cant help that, all I can do is make it look and feel as realistic as possible and be satisfied myself with the result. I've put far too much work into this so wont be letting any third party reservations worry me. Other people will be free to make their own judgements, which is fine.

BTW even though the obvious length restrictions have been posted for all to see on my site for many months now, and there have been thousands of people visit, I have had nothing but encouragement from the community so far, including your own comments, which is gratifying.

But the way I look at it, the only alternative was no great prospect, ie for us all to continue to just sit and dream about the greatest road circuit in the world, bar none!!

Bill Guillaume

Jim This looks incredible.

I tried to get your Track Guide but it cuts off about 1/2 inch of the rh side of page? How do I get this printable guide to print the whole page across? What am I missing here.



I have a 19" monitor, but set up my web pages so they should fit at least a 17 inch.

I had the same trouble you had using the file menu to order the print, but got a good sideways fit and all the text printed eventually by right clicking on the actual page and ordering the print that way.

If that doesnt work, you may need to look at your printer preferences.

I still cant figure out a way to modify Page breaks though, printing HTML this way. Maps and text can be cut in two.

If someone knows how, perhaps they could post here.

Thanks John......

[portion of answer]

BTW, the real problem with textures, and what takes a lot of time, is not so much getting good raw material, its converting it to something that looks good as a repeating texture and converting textures to 4 bit so they still look as good as 16 bit.

EG That stone wall in my Avatar is 4 bit manipulated from a digital photograph of a short stretch of stone wall, only about 3 feet, in one of my neighbour's driveways here in the Adelaide Hills!

As with all the other 4 bit textures I made, I had to change the horizontal perspective, rotate it , crop it, find a colour palete that looked natural when converting from x million colours [16 bit] to 16 colours [4 bit] , then cut and paste some individual stones, make the vertical row on the top so that it looked like the IOM wall I wanted to replicate, then airbrush some of it so that the brightness of the texture was fairly random/even, then make sure that the ends dovetailed together so you wouldnt notice the joins as it repeats on the wall evert 5 metres [ If you dont do those last two things for a repeating texture then you get an unatural 'strobing' effect especially driving by at high speed.]

4 bit saves masses of 'aggregate' texture size and is the only way to get such a texture intensive track like this to be frame rate friendly, even in D3D with a Geforce..

4 bit is HARD to get the colours right, 16 bit is EASY by contrast, just take a good photoghaphic image, size it , perform a few of the easier steps above, convert to a Mip and Bingo... done....

Looks great, but the 'Puters' we still have these days have a tough time handling a lot of 16 bit on complicated tracks and to be frank, you just dont notice the difference between a 16 bit wall and a well made 4 bit wall when you are flashing by at 100 mph +

I tried 16 bit at the start with this track, but the frame rate 'hits' even on my P4 1.7 GF 3 500TI were far too great.

John Nelson

Jim, I loved your Adelaide track, but this project is insanely ambitious!! Best of luck to you.

Also, if you are in need of any seamless textures, let me know. I have several CD's worth of textures for walls, concrete, stone, etc. if you need any that can be tiled, and would be happy to provide them to you.

Pete Richardson

Am looking forward to doing a lap of the Island in GPL just so I can see how well I can remember my way around. I always struggle remembering the sequence from Ginger Hall to Ramsey....


Just a word of caution about remembering and comparing 'sequences'

I have represented all the main corners and there are 164 turns/kinks in my representation of the IOM MC, but there are many more in the real IOM

As its limited by GPL track length restriction to 24 km and the real course is 63 km long, straighter repetitive sections like the one you mention have had to be simplified and shortened considerably.

See the IOM MC Guide on my site for full design, maps and other detail.

Biker Jim UK

Lookin good Jim, how's the fps?
Biker J


I have detail bias set just over half way, have all effects turned on and most textures in the mirrors. I also use all the 16 bit cars mostly GPLEA except Bruce's Brabham, which is the important bit.

I have a 1.7 gig P4 and G3 500 ti

FPS are affected mostly on this track by how many cars are in the close draw distance.

This is what I get

Driving in the pits with all cars still there 26/28fps [Lot of detail in the pits]

Back of grid behind 19 AI 33fps

After start before crossing the S/F line 28fps

After crossing S/F line 33fps

100 metres after the S/F line 34/36 fps

From Bray Hill 36 fps solid

First slow turn at Quarter Bridge with all cars close 33/36 fps

Next straight before Braddan Bridge 36 fps

Braddan Bridge tight 1st gear left/right switchback 30/35 fps

Thereafter 36 fps solid everywhere, including all the above as soon as the cars spread a bit.

FB [draw distance] files are not quite optimised yet, so I will get some more improvements without having to watch graphics 'pop ups' in front.

Good enough?

The track itself is frame rate friendly, being all but 1% 4 bit textures. But these still look good I think. Some tuning of the 'strobing effect' on some and a little bit of colour correction on others is still needed,but nearly there.

If you read my IOM Course Guide, I acknowledge that present Bike laps are up to 127 MPH average [David Jeffries], but the 1967 Senior TT times were 110 MPH, and so the times achieved by the fastest GPL A.I. of 111 MPH are spot on, if you think, as I do, that they would be about as fast as the bikes around there.

Jeff Reid Thursday, 3/6/03, 1:55 AM
Ignoring the AI aspect, what would it take to make a full Ilse of Mann track, if the scenery were kept simple (now that you have done the 60% version)? There are probably a few that would be interested in this, even if only hot laps (and maybe online) play were usable... Regardless, thanks for all the hard work. Hope to see the track soon. IIRC, the average speeds just broke 120mph at TT, with about 18 minute lap times.


1)  Building the full 63 km Mountain Course for GPL

2)  Track Sections / Sequences

3)  Track Width

4)  Draw Distances / Texture Sizes / Frame Rates

5)  Printing The Course Guide
ISLE OF MAN  MOUNTAIN COURSE             Frequently Asked Questions