Annoying persistent "Hatch Obstructed"

[TiktaalikDreaming]

I've been working on building a NAR MEM (Mars Excursion Module).  My issue is that the moment I attach the base, the lab's hatch is obstructed.  And it shouldn't be.  At least as far as I can tell.  I'm wondering if anyone has a really clear idea of what triggers the "hatch obstructed" message.  I've moved a lot of colliders.  Some I've even shifted to non-convex, even though that will stop working after 1.1.  even though those didn't really obstruct anyway.  Visible, non-collider mesh doesn't appear to be obstructing either.  Is there some implied bubble of "do not obstruct" space I should know about?  I'm assuming a kerbal sized space outside the airlock part-trigger/collider.  But I just can't get this working.

[pizzaoverhead]

13 minutes ago, TiktaalikDreaming said:

I'm assuming a kerbal sized space outside the airlock part-trigger/collider.

Have you added a box collider for the airlock exit point? It's a required component that's placed on the outside of the hatch, set on layer 21 and marked as a trigger. See here for details.

Example:

 

Edited March 23, 2016 by pizzaoverhead

[TiktaalikDreaming]

8 minutes ago, pizzaoverhead said:

Have you added a box collider for the airlock exit point? It's a required component that's placed on the outside of the hatch, set on layer 21 and marked as a trigger. See here for details.

Example:

 

Yep.

The hatch works.  There's multiple parts.  The lab piece has a hatch.  The descent base obstructs it.  Just the lab, the hatch works fine.  I just added parts, tested, one at a time, and it's definitely the descent base obstructing the hatch.  But no component of that part *should* IMHO.  That said, the descent base collider is a group of colliders.  Possibly the most complex collider I've built yet.

[NecroBones]

 

Screenshots? Usually the "obstructed" just means that something is intersecting with that collider.

 

Something to consider-- is the hatch box-collider intersecting the pod's colliders? Various tutorials have suggested this, but that always gave me problems. For me, it's worked best to have the hatch collider almost touching the pod's colliders, but not quite, leaving an almost imperceptible gap between them.

[nli2work]

It's really hard to say much without seeing the colliders on the lander base and the lab part that is being blocked.

most likely some part of your descent base collider is clipping your lab part's exit collider. try nudging the exit collider around so there's no clipping after assembly. or try a capsule collider for exit hatch, the rounded ends might be enough to get you the clearance you need. the exit collider doesn't have to touch the lab part's other colliders, you can offset it from the door mesh if necessary.

Edited March 23, 2016 by nli2work

[TiktaalikDreaming]

OK, I've organized screen shots.   Colliders are a bit hard to see.  (Anyone else have that thing in Unity where they're invisible until you untick and retick Convex?)

@NecroBones the hatch box doesn't intersect the pod's collider.  It did initially, but I already chased that rabbit hole.  It sits a short distance away, helped by the hatch mesh shape protruding past the pod collider.

@nli2work my bet is on some sort of clipping, yes.  I'm about to start disabling colliders to see what's causing the issue.  I'm starting to think the collection of 27 mesh colliders in one part might be going too far, and KSP is doing some summarization.

 

[TiktaalikDreaming]

While people ponder if 27 meshes for collider shapes might be too much, I'm redesigning those.  It occurs to me that;

1. The gap for Kerbals to go between layers and walk out along the landing legs only ever worked because I had a full scale part with half scale kerbals.  Now that I've kerbal scalled the parts, it doesn't work.  So I can remove some complexity and the stairs.

2. The floor and base colliders can be the same.  Esp considering item 1.  And the inside and outside wall colliders can also be the same.

 

 

[nli2work]

Hm... maybe your exit collider is too small? It should be large enough to fit a kerbal... if a box, it should be around 1m on all sides. I've had some exit hatches in tight spaces that worked without any problems. looks you got plenty of space around the exit. nvm... you said that's been working fine.

I'd start with removing the wall collider, just drop it outside the export hierarchy and export, see if exit is blocked. and do the same for the other colliders near the exit if the wall collider wasn't the problem.

Edited March 23, 2016 by nli2work

[TiktaalikDreaming]

OK, "solved".

Either there's issues with overly complicated sets of colliders, or (I'm leaning towards this explanation) there was something out of place with one of my 27 colliders.  I removed all the colliders, created new collider meshes in blender that merged a bunch of the others and dropped the colliders for the part down to 13 simple ones (2, replicated in a circle of 6 plus a central one).   And now it works.

 

[NecroBones]

 

I think it's the latter explanation as well. I don't think the number of colliders is a problem, but it's possible one of them was screwed up somewhow. Maybe extra disconnected vertices not contained in a polygon, which Unity generally hates. I'm glad that worked!