Description of the Category for a track or switch

[ademes]

Hello,

Could someone explain in details the "Categary" function when editing a track.  The current possibilities are : railroad, road, water, air, 3d model only.  I need to understand what happen if I change the category of a track.
In the same edit pannel, could someoe explain what is the difference for type = "spine" or "virtual".

Many thanks in advance

André

[metallix]

Hi Andre'

A very basic explanation for now: If you change a track from either rail or road or water or air into a 3D model only, it is no longer working as a track. So no vehicle will stick to it or maintain a speed. This comes in handy for example when using roads with the spline(s) build in, but wanting to ad or change the path of a track. All that's required is the new layout made of some rail tracks (best then saved on a separate layer to turn them invisible/visible as needed) and use the road track as a 3d model ......for the looks only.

There is probably more to it but I am curiously waiting for someone like @Bahnland to enlighten all of us with an in depth and most likely pictured run down on this subject.

Cheers

Tom

[ademes]

Hi Metallix,

Yes, I discover the reaction of a track with "3d Model Only", but I don't see up to now the usage of such a category.  And I don't know what is a "spline" for 3d.
So, like you are, I'm waiting for some complete explanations as the Wiki is not clear at all on this point.

Regards

André

[BahnLand]

Hello Andre,

because Tom has given a broad hint, I will answer too, but not not very detailed, because I'm very busy otherwise at the moment.

As Tom has explained correctly, the categories "rail", "road", "water" and "air" are defined to describe spline models to be used as rail tracks, streets, waterways and air paths. Currently, their is no functional difference between these variants of splines. Each of these variants can be used to specify a path, which can be followed by a vehicle along the line defined by the spline configuration. Only the variant "3d model only" doesn't support this functionality. It is used to build a 3D modell oriented on a given spline, which is based on a simple 3D-Model, which will be joined like a pearl necklace - but without track line functionality.

Specifying the type "virtual" instead of type "spline" makes the model invisible. You can so specify incisible track lines, e.g. to realize a track line for planes in the air space.

Many greetings
BahnLand

[Henry]

Hello Andre

 Splines are generally understood as a sequence of curves that fulfills a defined condition at the beginning and end of the entire curve part. With this funktion you can easely built a track to connect two points in your layout. To understand this, the following must be said again:

    A spline is a function that is composed of polynomials of at most nth degree. At the points where two polynomial pieces collide, e conditions are set, e.g. that the spline mark can be continuously differentiated. ...

    For flex tracks or 3D models, the condition is that - seen over the entire curve - a tangential adjustment with the radius R = FINITE or without curvature is achieved at the beginning and end of the curve. The adjustment is made by marking and dragging with the mouse. However, this has no influence on the shape of the curve. The visual course is not predictable.

On the other hand, you can also fill splines with geometric data. Even then, you have clear defined conditions at the beginning and end of the curve for further construction.

Regards.

Henry

 

[ademes]

Thank you all for your explanations.

Regards

André