WHAT THE HECK (or other expletive) Just Happened?

Short version, my 3D model went insane when I hit save (Ctrl+S).

Longer version (not sure what happened so I’m not sure what is relevant, so it’s long):

I was working on the part that I posted this about (a third part in the same file):

I got most of it laid out like I wanted but without the “floor” and other pieces, made a copy of it and put it next to it and kept going, put a floor in, laid out the cutouts I wanted in it, then started laying out the cutouts in the side rails. Since I started by importing an .STL of an existing part to get some of the mounting dimensions off of it (some of which I know are wrong but I know which way I had to move them) I had hidden geometry turned on because I spent some time cleaning it up before messing with things. As I noted in a previous post I checked my geometry with Solid Inspector^2 every few steps to make sure that I didn’t have some mess to clean up.

I laid out the cutouts on the RH side rail (on the RH/front of the pic that I’m going to attach) I started getting hidden geometry dotted lines showing up in weird places, like the opposite wall that I was working on or on the little block in the back left corner of the model.

Once I laid out the cutouts on the RH (longer) side rail I move/copied to them to the LH rail and when I positioned it I got openings into the inside of the rail where the cutouts were pasted. I closed them by drawing a line across them the pushed them through the rail to make the cutouts. I went back to the RH side and tried the same and when I pushed them through till it showed that it was on the opposite face the face wouldn’t open when I released it. I tried selecting it and hitting delete and it looked like it put a new face there. I also noticed that the outside face of the RH rail was getting more hidden geometry dotted lines.

I ended up pushing them through the opposite face, intersect faces and then deleting the stuff that pushed through. Solid inspected, spun it around a few times to make sure everything looked good and while I debated adding an extra wire pass-through I figured now would be a good time to save it.

I hit Ctrl+S and this happened, it looks like large sections of the model got dragged to the front RT of the model:

.

I hit back (Ctrl+Z) and it got worse (things just started disappearing), hit redo (Ctrl+Y) a few times and found that I could go back to the mess in the above picture, but even weirder, I had further to go forward (I didn’t do anything to it after saving, I checked in the edit pulldown and it had a “redo cut” what is a cut?) and I got something without the lines, the front face cut off the part and 2 of the side holes closed:

I’m afraid to go back or forward with it now, I’m hoping that it doesn’t crash in case going back or doing something to it as it sits can fix this (this is one of the files that I had Sketchup crash with when scaling).

I opened the saved file in another instance and it looks different. It has the same to cutouts on the sides closed but it has all sorts of crazy hidden geometry showing on the RH side rail:

What happened? How do I fix it? How do I prevent it (if it’s something I did)?

The other weird thing is that since this one has crashed a few times I have a bunch of different versions, the filename, autosave, autosave_autosave, autosave_autosave_…_1:


and they all appear to be very similar, all appear to be after the save and have the same icon but don’t have the same timestamp (they’re scattered over a 2hr timespan before I hit save and things went crazy):

I’m sure someone will want to see the .skp
AutoSave_A8_Front_Brace_mmp.skp (1.1 MB)

display issues of this type often are related to one of the following:

Clipping
• small Model Size (mm area) -> scale it up 10x times
• Display Driver -> update

1 Like
  • No weird field of view or anything listed in the clipping article. According to the article it shouldn’t affect the actual model, just appearnaces, this did weird things to the model.
  • DaveR is continually lecturing me about that, the reason for the autosaves/crashes is that it happens when I scale the model. This is currently scaled 100 (20mm actual size, 20000mm in the model), it’s not too small.
  • I have the most current display driver (Lenovo Yoga 2 Pro, there haven’t been any driver updates for probably 2-3years), not sure this would affect the model.

I have no idea what happened to your model, but when I’ve worked on parts (or assemblies) I’ve broken things into multiple solid components - easier to work with, faster (IMHO) when you need to make a change or explore a design direction, etc.

Prior to printing I would union them back together as needed.

1 Like

Was the imported STL file yours or authored by another?
SU has a certain tolerance for non-coplanar geometry.
Checking for solid is one thing; confirming the imported geometry is truly coplanar and worthy of reuse is another.



When that occurs, it’s a red flag indicating geometry is out of plane.
SU automatically breaks (triangulates) a face when an operation moves its bounding edges out of plane.

It’s wise to stop at the first sign of such trouble.
Push unit precision to six decimal places and use the Query tool to find the error.

Query Tool — Extension Warehouse

1 Like

Your first screen-shot image reminds me of the following. On numerous occasions (with SketchUp Pro 2014/15/16 at least) I have seen amazing explosions of geometry in the following scenario:

  1. save the model file
  2. the automatic validity check finds problems and makes changes to the model (introducing holes into what had been a solid component)
  3. I tell SketchUp NOT to attempt to fix the model, just leave results of the validity-check as-is
  4. execute the Undo function (to attempt undoing the changes caused by the validity-check operation)

The result of the Undo operation sometimes is creation of triangular faces (I’d guess dozens of them) that all stretch to a common point. This has happened to me often enough that I have learned never to use Undo after a validity-heck “gone bad.”

(To be clear: it’s the validity-check operation that creates little holes in the model, and it’s the undo of that validity-check operation that creates big triangular faces stretching to a common point. The little holes produced by validity-check are the results of merged or slightly relocated vertex points that were very close to each other. These days when a validity-check operation produces such results I manually fix them up.)

1 Like

[quote=“Geo, post:6, topic:50877, full:true”]

Was the imported STL file yours or authored by another?
SU has a certain tolerance for non-coplanar geometry.
Checking for solid is one thing; confirming the imported geometry is truly coplanar and worthy of reuse is another.

I started with someone else’s, but it was literally a file that was used to print a part that is already in use and I only used it for dimentions. Once I located things I literally ripped took both side walls down and re-drew them (set a rectangle on the base, push pulled it up…), I know it was co-planar when I started.

When that occurs, it’s a red flag indicating geometry is out of plane.
SU automatically breaks (triangulates) a face when an operation moves its bounding edges out of plane.

It’s wise to stop at the first sign of such trouble.
Push unit precision to six decimal places and use the Query tool to find the error.

Query Tool — Extension Warehouse
[/quote]

Can you explain more?

  • looks like the query tool shows the exact location of the mouse, I’m not sure how this helps you fix this since that depends on how you move the mouse and what you’re doing. How do you use this to figure out/fix this problem?
  • how did something that was coplanar (a rectangle push/pulled up to a “wall”) end up not copanar? Similarly the small box I mentioned in the back left hand side in the orignal .stl had an ugly curve draw on one side, I deleted that face, deleted the curve and re-drew it using a the rectangle tool, then I noticed later that surface suddenly had some hidden geometry lines on it (assuming it’s not coplanar now), how did that happen if I haven’t touched it since I drew it with the rectangle tool?

If you click the Query Tool on a point or intersection or an edge, it displays the coordinates. You can compare different points, to see which is out of plane, when as suggested you have decimal units and a high precision setting.

Well, I feel like I kind of know what the problem is, I don’t really know how I got there, why sketchup allowed it to happen, and I don’t really know how to fix it besides redrawing everything :-/

This. The faces that look flat are in fact, not flat.

Yes, the Query tool dynamically displays the coordinates of the cursor.
Hover the cursor over geometry and notice the Inference Engine and Query tooltips indicate the name and the exact coordinates of the inference point.

Inference Types — SketchUp Help

SketchUp automatically creates a Face provided the Edges that bound it meet the following conditions:

  1. All the Edges are coplanar.
  2. The Edges form a closed loop.
  3. No stray Edges, coplanar with the closed loop, project inside the loop.
  4. The Edges are not too short.

Given one is reasonably certain conditions 2 thru 4 are met, then condition 1 is the problem.

If the geometry in question is supposed to be parallel with a plane of the World Axes, say, parallel to Plane X,Z
Then the Y coordinates of said geometry must all be the same.

The Query tool can only help identify what’s wrong.
Fixing the model you shared most likely will take longer than building a new one.
Notice the gaps in the side rail cutouts.



An autosave titled file is automatically generated by sketchup if the program fails to save or close correctly, i.e. Crashes. Sketchup is maintaining autosave files in the background all the time (if you have the option selected) but when you save your file while closing it and the operation is successful then sketchup erases the autosave. If you are seeing autosave titles files it is the result of a crash, that rescued file is the last saved version before the crash.

If you then open the new “autosave” titled file and subsiquently experience another crash then sketchup rescues that file with an " autosave autosave" file and if you open that one and crash again…

This is not that uncommon as it’s natural the try the offending operation a few times trying to figure out a way around the problem. I have to beat my head against any given wall at least seven time to learn anything. In this case the fewer the "autosave"s in the title the earlier the file was generated in the process loop, perhaps going back to the earlier files can help you find an un-corrupted version. Good luck.

This topic was automatically closed 91 days after the last reply. New replies are no longer allowed.