Patched conics issue(?)

[Ylw]

So i don't know whether this is a bug or something because i never see this issue with any streamers but my patched conics accuracy is horrendous, every single encounter (planetary, craft, anything) flickers between actually being an encounter or not several times a second, even if i know for a fact that im going to smash straight into the object.

The weird things is when the system switches to on rails it resolves to being an encounter every time.

I've even tried increasing the physics time per frame to 60% of every frame and it doesn't help.

Could this be some kind of rounding error or some math issue because of a destabilizing overclock or something? I ask this because ill also get issues where my craft with slide to one side quickly then lurch back to where it used to be like the game thought the craft was a few meters to the left one seconds but it was back where it was the next.

Edited May 26, 2016 by Ylw

[Death Engineering]

5 hours ago, Ylw said:

So i don't know whether this is a bug or something because i never see this issue with any streamers but my patched conics accuracy is horrendous, every single encounter (planetary, craft, anything) flickers between actually being an encounter or not several times a second, even if i know for a fact that im going to smash straight into the object.

The weird things is when the system switches to on rails it resolves to being an encounter every time.

I've even tried increasing the physics time per frame to 60% of every frame and it doesn't help.

Could this be some kind of rounding error or some math issue because of a destabilizing overclock or something? I ask this because ill also get issues where my craft with slide to one side quickly then lurch back to where it used to be like the game thought the craft was a few meters to the left one seconds but it was back where it was the next.

This has been a KSP bug for as long as I can remember (started in 0.18) but seems worse in 1.1.2.  I try to guess the perfect maneuver node by tweaking it blind from a known-good node. As you said, the intercept will occur even though it doesn't always show up.

[Gaarst]

As I understand it, the original issue is a conversion problem between two number formats used to store orbital data (PhysX uses 32bit and KSP uses 64bit formats, or something like that) that causes the flickering. This has been here since whenever map view was implemented AFAIK.

Now, since 1.1, there have been issues when orbits "decay" when simulating physics because of the way CoM is calculated in a ship. This may add to the issue.

To solve this, I invite you to grab your pitchfork and go complain all over the forums like some of us do (myself included) until a patch comes. It may not be efficient but it helps spending time in the meanwhile.

[Red Iron Crown]

It's rounding errors. When off rails (1x time or physics warp), the Unity engine uses 32-bit variables for all the position/velocity data. Which is fine for the distances involved in most Unity games but comes up a bit short for the large distances in KSP. Going on rails (5x warp or more) switches to KSP's orbital calculations, which use 64-bit variables and are thus more precise.

[Kosmognome]

11 hours ago, Ylw said:

o i don't know whether this is a bug or something because i never see this issue with any streamers but my patched conics accuracy is horrendous, every single encounter (planetary, craft, anything) flickers between actually being an encounter or not several times a second, even if i know for a fact that im going to smash straight into the object.

Do you have SAS on? If you, disable SAS, warp a tiny amount and go back to normal (or stay on the lowet warp setting).

 

SAS constantly applies tiny amounts of torque, and thus encounte wobble. Its much bette without SAS, and warping kills any rotation.

[samstarman5]

I do believe this is addressed in this thread 

and as stated in there by NathanKell, it is being worked on.