So what exactly are conics?

[SergeantBlueforce]

I'm asking as I saw a thread the other day saying that if you altered a config value related to them you would be able to see planet intercepts before they happened (with manoeuvre nodes and other things)

Can anyone explain what they are to me?

Edited July 13, 2014 by SergeantBlueforce
Marking as answered.

[Padishar]

A conic section is the curve you get when you cut through a cone with a flat plane. Depending on the angle of the plane the curve can be any of circle, ellipse, parabola or hyperbola. A body that is only being acted on by gravity (inverse square law) by one body will always follow one of these paths. As KSP only ever has one body that exerts a gravitational force on your ship (the body whose SOI you are in) then the path of your craft in that body's SOI is always one of the conic sections.

[Wallace]

The config change in question is how the different conic sections are displayed in map mode, tricky to explain bit it's about how they are shown to connect up when you change soi.

Now say if you plot a mun intercept, when you're focused on kerbin the trajectory shown round the mun (in orange) is not very clear, it just looks kinda squiggly, but if you focus on the mun it will change and look correct, but no longer connect to the blue part.

That's cos it automatically changes the conic display mode, from relative to your current body, to relative to the local body. That's just one display mode change, there are 5 in total, and they can all be useful in showing your trajectory in clearer ways in certain situations. The most useful one however is the one i just described which squad added as an automatic change now.

If you have mechjeb, you can swap the modes easily using the manoeuvre node editor.

Edited July 12, 2014 by Wallace

[UbioZur]

That post should show you the difference easily.

I believe there are a few video on youtube also.

[Red Iron Crown]

There's two separate settings related to conics:

CONIC_PATCH_DRAW_MODE: Sets which method for drawing trajectories that cross SoI boundaries will be used. The post UbioZur linked gives good examples.

CONIC_PATCH_LIMIT: Sets the maximum number of SoIs through which the map view will predict your trajectory. The higher this number, the more SoI transitions can be predicted, but there is a performance penalty with higher limits.