1.0 CoLoffset and CoPoffset?

[Squiggsy]

So I'm in the middle of designing a command pod and other parts for an orbiter/lander i'm working on and when i checked out the Mk1-2 Command Pod to see what had changed I noticed these two extra settings, I know CoL will be center of lift (or coefficient of lift, not actually sure which here but guessing center since it's xyz coordinates), but no idea what CoP is, not sure what changing them is going to change, or whether I can omit them for now?

also as a side note I've seen people are converting to DDS textures but I haven't found how they are doing this yet anyone have a clue? I like the sound of reduced memory footprint!

[CaptainKipard]

DDS4KSP converter

[Squiggsy]

ah thank you kindly! any clue on the CoP and CoL and how to use them properly yet? haven't seen any mention of it at all

edit: engines seem to have changed as well, anyone know what the new key in atmosphereCurve does? seems to go 0 1 then 8 in the one i'm looking at at the moment, and the 8 is set to 0.001

Edited April 29, 2015 by Squiggsy

[CaptainKipard]

I don't know about CoP and CoL. I think the new key is for Isp Changes.

[Squiggsy]

ah right so like the rate of change between them/ shape of the curve between them then? hmm I haven't noticed much negative effect from just omitting CoP and CoL yet, but I think it just makes it behave like pre1.0 if you do, and I'd like it to work as somewhat of a lifting body since im attempting a propulsive landing style capsule (going well so far, first successful test had me land right on the VAB Helipads after having dropped from 20,000m , and perfectly running out of fuel!)

thanks a bunch for the help!

[NathanKell]

CoPOffset shifts where the drag force is applied (by default it's applied at the CoM). In order for command pods to be stable, the CoM must be in front of the CoP. However, since the bottom is very draggy, you need to shift the CoP up to ensure it's above the CoM.

If the drag is applied at just the CoM, the pod will just maintain whatever orientation it has, since drag will not exert torque.

[CaptainKipard]

CoPOffset shifts where the drag force is applied (by default it's applied at the CoM). In order for command pods to be stable, the CoM must be in front of the CoP. However, since the bottom is very draggy, you need to shift the CoP up to ensure it's above the CoM.

If the drag is applied at just the CoM, the pod will just maintain whatever orientation it has, since drag will not exert torque.

Is there a science to figuring out how far to offset the CoP?

[Squiggsy]

CoPOffset shifts where the drag force is applied (by default it's applied at the CoM). In order for command pods to be stable, the CoM must be in front of the CoP. However, since the bottom is very draggy, you need to shift the CoP up to ensure it's above the CoM.

If the drag is applied at just the CoM, the pod will just maintain whatever orientation it has, since drag will not exert torque.

Thanks a lot for this! ok time to get experimenting, trial and error is always the most entertaining way to do these things moar explosions!

[NathanKell]

Pretty much trial and error--the further back it is, modified by mass and torque, the "snappier" the part is in assuming orientation.

[Beale]

If I'm reading it right, do these new attributes mean I'll be able to implement a single-part lifting body capsule (I.E. the Kliper) that isn't inherently unstable? Complete control of COL relative to COM.

If so, this may be one of 1.0's best features for me

Edited April 29, 2015 by Beale

[CaptainKipard]

Your idea made me think about my mods wrt this and I came to the conclusion that this may not be as useful as you think. I remember from Scott Manley's videos that wing angle plays a major part in how an aircraft behaves without SAS, and I'm not aware of any values that would simulate that. So unless the Kliper has it's wings horizontal laterally, instead of angled slightly up, then this might not be the best idea.

[Beale]

Your idea made me think about my mods wrt this and I came to the conclusion that this may not be as useful as you think. I remember from Scott Manley's videos that wing angle plays a major part in how an aircraft behaves without SAS, and I'm not aware of any values that would simulate that. So unless the Kliper has it's wings horizontal laterally, instead of angled slightly up, then this might not be the best idea.

Thanks for the info, it does indeed have its wings perfectly horizontal, but perhaps splitting the wings into separate parts will allow for a non "hacky" solution for gentle gliding.

[LazarusLuan]

CoP refers to center of pressure - here's an article that details its use and effects: http://www.nar.org/NARTS/TR13.html

[Squiggsy]

CoP refers to center of pressure - here's an article that details its use and effects: http://www.nar.org/NARTS/TR13.html

thanks for that! informative little read there