Crash explosion sprite issue

[Daniel3D]

Most, not all, custom cars have the bug. (Not checked with all cars)
It might be related to scaling, that seems to trigger the bug.
But I can't find a relationship.

[Daniel3D]

Ok, just did a quick test.
I build an entirely new car model in stressed from scratch. (just insert shapes in stressed and manually positioned all vertices)
it took me 23 minutes and made a few mistakes (two wheels were inverted) and it is a simple model.

It's an Eastern car, and it is called "the flying carpet".   

I know, it is not much. But it doesn't have the bug..
That was what i wanted to know. . Now, let's see if it can get the bug, and what has changed when it does,.
(I used the PMIN files as filling. I attach the shape file for safe keeping)

[Duplode]

If you save an original P3S as an 3SH in stressed you can edit the file in Carworks.
If you then copy Car0 to Car1 in Carworks and safe, you have the bug.
There is something in Car0 different from Car1 in the original cars.
So any car with an scaled edit of a Car0 used as model for Car1 will have the bug I think.

This car0/car1 theory might sound odd at first, but I do feel there's something to it. The car1 of the Skyline, which doesn't have the bug, was made out of the Corvette car1, with the car0 being based on a scaled up car1 rather than the other way around.

[Daniel3D]

I think that you are right. I also tested with moving car1 to car0 and back. That doesn't produce the bug


But I think there is a complexity factor of some sort as well. The best chance I can think of to analyse is the simplest model that gets the bug.

So if anyone has half attempts, tests or failures lying around. Please share them for science 😜

[alanrotoi]

What about a negative height issue of the polygons?

[Daniel3D]

What about a negative height issue of the polygons?

I'm not familiar with that issue. How can I create this?

[alanrotoi]

I mean if a polygon has a negative Y axis (from Stressed point of view) coordinate value. What if this is the origin of the bug?

[Daniel3D]

I'm afraid that I still don't understand what you mean. 
Can you give me en example?

[alanrotoi]

When you build a car you have to give coordinates to every polygon. I think ground level value in vertical coordinates is 0. Stressed allows you to build polygons under 0 value. Maybe there is something here.

PS: I say vertical coordinates or height because Stressed calls this axis "Y" but the rest of humanity calls it "X"

[Daniel3D]

Only blender user's and a few others see X as vertical. Mostly y is used for the vertical axis. As does stunts.

But I don't think that any of the cars I tested with the bug have negative y axis values. I will look into it though.

[Cas]

A negative value could have something to do. If that's the case, it should be in the vertices of wheels, because all cars have all other polygons higher than the wheels. The way to test it is simple (in comprehensive terms): just verify the vertical coordinate of each vertex and check it's equal to or greater than zero.

Since custom cars have been created without thinking about this, I would say that it's a possibility, but I'm surprised that it's more likely for the bug to happen than for it to not happen, so my guess is that this is not the problem, but we definitely should check.

I normally choose a coordinate system that uses Z for the vertical whenever gravity is involved, so maps are (X, Y). This is the coordinate system used in CarWorks and in Blender. The other very commonly used system is the one with Y for the vertical, which is used by Stunts, by the OBJ file format and by Minecraft, to give some examples. I personally don't like that system because I feel that the vertical is not like the other axes when gravity is present. Another reason is that the system with Y going up means that Z goes negative away from the screen, which is not intuitive (unless you use a left-handed system), but as long as there's consistency, every coordinate system is OK really.

[Daniel3D]

Of course. I didn't think about the wheels..

A negative value could have something to do. If that's the case, it should be in the vertices of wheels, because all cars have all other polygons higher than the wheels. The way to test it is simple (in comprehensive terms): just verify the vertical coordinate of each vertex and check it's equal to or greater than zero.

It is not that simple.  The wheel vertices ar only on the top of the wheel. So you would need to substract the  top y from the bottom y coordinates.
But that is easy to check manually.

[Cas]

It's true. The outer edge can be represented downwards, but most commonly, it's done upwards. It's unlikely for a negative to be present, then. It would have to be a significant design mistake. The distance between the car base (or wheel centre) and the ground is very easy to see.