Recent posts

#1

Stunts Chat / Re: SimCar laps on Stunts trac...

Last post by Matei - Today at 08:39:07 AM

Actually the kerbs in Stunts are holographic road indicators.

https://www.thesignchef.com/blog/holographic-traffic-signs

Whoever gets outside of the road should be disqualified and indeed Stunts shows very advanced technology, including cars with electronic damping so that they don't bounce after landing from a jump.

https://cartriple.com/bmw-electronic-damper-control-edc/

#2

Stunts Chat / Re: SimCar laps on Stunts trac...

Last post by Duplode - Today at 05:14:56 AM

Indeed, the low detail element for the road on the hill has kerbs, but the car doesn't interact with them in any way. That's really annoying. Can GAME.RES/PRE be modified to fix that? Just asking.

Modifying GAME.RES wouldn't be enough on its own. Giving a contact model to the hill slope kerbs amounts to adding a new kind of obstacle for slope roads (something analogous that already exists in the game are the slalom blocks). For that, we'd need to extend the relevant functions in seg004, most likely after analysing and porting them to C in the context of Restunts. We roughly know what it'd take, but there's still a fair amount of work to do until we get to that point.

#3

Stunts Chat / Re: Rotoi Challenge - #rotoich...

Last post by Matei - Yesterday at 10:01:37 PM

In my country (Romania) the beginner symbol at drivers was

Then why didn't you try with a Romanian game? Is it because you don't trust Romanian cars?

https://en.wikipedia.org/wiki/Dacia_L%C4%83stun

#4

Stunts Chat / Re: Rotoi Challenge - #rotoich...

Last post by alecu - Yesterday at 08:42:15 PM

Hello. I did the #rotoichallenge, here is the replay file of it, and also YouTube link to the video of it.

https://youtu.be/p_DpVZ99HWY

#5

Stunts Reverse Engineering / Re: New mod: extended line of ...

Last post by Matei - Yesterday at 02:03:54 PM

So that's why the rendering still had some hiccups. Ok:

Code Select Expand

485:     + 2*abs(lookahead_tiles_supersight[si].width) <= 4)

#6

Stunts Reverse Engineering / Re: New mod: extended line of ...

Last post by HerrNove - Yesterday at 12:29:57 PM

Wait, at 485 I must have forgotten to wrap lookahead_tiles_supersight[si].width into an abs. This means that, during redraws, the objects on the left of the camera (with width < 0)) will preserve more detail than the ones on the right. This is not super important since, especially with 80 tiles, you are extremely unlikely to overrun the 13K buffer and hence to need redraws. But it's still something that should be fixed.

#7

Stunts Reverse Engineering / Re: New mod: extended line of ...

Last post by Matei - Yesterday at 11:09:04 AM

Now that's better.

Code Select Expand

  4: #define TILES_TO_DRAW_COUNT 80
 76: /*{  -6,   4 },
105: {   5,   3 },*/
484: if (lookahead_tiles_supersight[si].depth
485:     + 2*lookahead_tiles_supersight[si].width <= 2)
744: tile_det_level = tile_detail_level[si];
Long view distance and with these settings track ZCT004 plays well in DosBOX with 13000 cycles.

#8

Stunts Chat / Re: SimCar laps on Stunts trac...

Last post by Matei - Yesterday at 08:45:30 AM

In any case, if our expectation is that the graphical models match the contact models while driving, our concern will mostly be with the high-detail models, as they are the ones used for the track element you are driving on at any given moment.

The low detail models are close enough to the high detail models and in my game they were better for the contact model, with one exception. Another observation:

 https://wiki.stunts.hu/wiki/Track_element_building

The graphical model, however, only controls the looks of the element. Actual physical behaviour is determined by a physical model. The physical model is only partly stored in resource files.

Indeed, the low detail element for the road on the hill has kerbs, but the car doesn't interact with them in any way. That's really annoying. Can GAME.RES/PRE be modified to fix that? Just asking.

This would be a sensible way to solve it, but it is not what Stunts does for the u/d cork contact models.

Anyway, for those "u/d corks"/spirals, the low detail models were better for the physics in my game. You can replace the z***.geo and z***.col models with the high detail models to check it out. Program "elrdline.c" in directory "src" is for eliminating the dashed yellow lines.

[*]

#9

Stunts Chat / Re: SimCar laps on Stunts trac...

Last post by Duplode - Yesterday at 02:36:22 AM

The car in Stunts moves like on zbtu*, not like on btur.

* the original zbtu

To find out which of the graphical models the car moves along, we can hex-edit the plane definitions in GAME.RES so that every other segment of the banked corner is flattened. btur has 18 segments, and zbtu has 9. Therefore, if the contact model followed btur, a car moving along the full length of a banked corner would bounce nine times, while if the contact model followed zbtu, we'd instead see either four or five bounces. The result of doing this test can be seen in the video below. The car bounces nine times, thus showing that the contact model follows btur and not zbtu. (If you want to reproduce the experiment, move the original GAME.PRE file out of your Stunts folder and replace it with the GAME.RES attached here.)

You cannot view this attachment.   

The contact models closely match the high-detail graphical models

No, see first attached screenshot.

While it's true that the pumps of the gas station only exist in the high-detail graphical model, that does not generalise to all other track elements. In particular, it's worth noting that the gas station and other scenery elements are pure obstacles, which the game handles differently than elements with drivable surfaces like banked corners. (It is these drivable surfaces that are in part defined by the GAME.RES planes.)

Since Mr. Hernove fixed the rendering, because the low detail models were also seen in-game while driving, at larger distances.

Indeed; in the unmodified game the low-detail models are used for distant objects while driving. I blame my failure to mention that yesterday on the lateness of the hour. In any case, if our expectation is that the graphical models match the contact models while driving, our concern will mostly be with the high-detail models, as they are the ones used for the track element you are driving on at any given moment.

The graphical models of the u/d corks have glitchy non-planar quads, which don't make sense in a contact model.

Non-planar quad means 2 triangles, so no glitch.

This would be a sensible way to solve it, but it is not what Stunts does for the u/d cork contact models. That's an interesting topic in its own right; later (in the weekend, maybe) I'll post a separate thread about it.

#10

Stunts Reverse Engineering / Re: New mod: extended line of ...

Last post by HerrNove - August 19, 2025, 11:23:14 PM

the game chooses the low-polygon version under the condition (var_FC != 0). I could have patched away the corresponding if instruction, but I found it easier to fix the value of the variable to 0.

Can I put the value of the variable back where it was? If so, where and how?

I replaced the mechanism with something slightly more complex (see start of Part III). The relevant lines in frame.c are 484–490, 744 and 801–805.