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What causes this herringbone / woodgrain effect

Discussion in 'Using Alibre Design' started by dsage, Feb 3, 2020.

  1. JST

    JST Alibre Super User

    Ok, this is TOO ODD.....

    I opened the small part this morning. It looked bad, with all the edges visible again. But the part was where it was when it looked good last night. Then I moved the "extra" part closer in again, AND THE EDGES THAT WERE VISIBLE MOSTLY WENT AWAY.

    Something is WAY wrong here. I'm going back to legacy graphics until this is sorted out.

    re-open problem 1.png
    re-open problem 2.png
     
  2. DavidJ

    DavidJ Alibre Super User Staff Member

    JST, did you save the assembly after things displayed OK ? I'm not accusing - just asking.

    I was having this issue all the time with this assembly, until I tried the 'isometric view trick' mentioned above. Then I saved the file. Now it opens with correct display every time.
     
  3. JST

    JST Alibre Super User

    Between the original post about moving the part away and having it work, and the next about it needing to be moved BACK to look right, I did of course save the part, in the condition (part moved away) that made it display correctly.

    It has been saved since, and now looks OK, except for the residual bits of the edges. Was like that when I looked at it just now ( I have not switched back to Legacy yet)

    Is that what you were looking for?

    I do not recall whether I saved the BIG file, I think so. EDIT, I just checked, and I did save it, it still looks bad with anything under about 2cm thick showing "all edges" despite the fact that I set it to "visible only".

    Now, when I move the extra part back to where the view was all messed up, it does not get that bad, but as the part is moved around, jaggies and (I think) transparency dance around all over the model, parts seem to disappear at random. It is very strange.

    So I DELETED the extra part. Now a similar "dancing" is going on as I turn the model around in the view. But the weird transparency of everything is gone. However, the visibility of edges that should not be visible now moves around with the viiew. Some parts show it in a particular position, and other IDENTICAL parts do not. Which shows changes as the orientation is changed. The white rack that I showed that on is a very good indicator.

    Also, triangular sections change to transparent, and back to color as the view is changed. I have seen that before, and not just with 20072, all the 2019 at least have done that, IIRC.

    I did NOT do the "isometric view" thing with either of them. I do not use the ribbon, do not have all the toolbars set yet after the new version (it did not import my settings), I do not have the display as was shown, and did not see the view thing on the menus, or I would have tried it.
     
    Last edited: Feb 14, 2020 at 6:57 PM
  4. JST

    JST Alibre Super User

    Well, using the isometric view did seem to fix much of it. The transparency problem is not entirely fixed, but the other stuff seems to be.

    No amount of zoom-in will fix the transparency and extra edges of the white rack frame in the big model. It is apparently a function of the percentage of the entire model size that the piece is. If too small, even if "too small" is an inch thick, then the part is treated as if it were transparent, and all edges are seen.

    That seems to be a separate issue from some of the other stuff, tiger stripes and jaggies. It must be related to the way thin things get transparent when zoomed out.
     
  5. Nick952

    Nick952 Member

    Just had time to try this on my desktop PC (as in my signature) and can confirm the herringbone effect is present with my setup.
    However selecting any view, not just Isometric, works on my system.
     
  6. JST

    JST Alibre Super User

    So, now, I open upo the big model, and it appears that the transparency issues went away, along with the tiger stripes and jaggies.

    I had opened and closed it several times before (not saving), and each time the white stand had transparency issues where every edge was seen. Now for no apparent reason, all of a sudden it is looking like what it is supposed to look like.

    I have absolutely no clue.... nothing was changed, and the file has been opened before and closed w/o changes, while the problem was active. I had to check the version to be sure that an auto-update had not occurred. Nope, still 20072

    I mean.... I guess I am happy now, but it would be nice to know what in the blinking backside of heck is going on.

    big model now works.png
     
    Last edited: Feb 17, 2020 at 12:57 PM
  7. JST

    JST Alibre Super User

    So...... Is there any resolution on this?

    Any clue on the what / why/ how of it?

    Or is it "resolved" because there are actions that "seem to" make it go away?

    At least they "eventually" make it go away, since I did not see the final changes immediately, it took several opening and closing sequences before all the effects disappeared. And time will tell as to whether they will "stay" gone.

    If it is any help, the large model that did it for me was one that was originally created several versions ago. It has been worked on under all of the ones that came out since it was started. That means it may be a real hash of different models and parts within it, although I presume they get updated when opened with a new version.

    The first version of the model was created with whatever was the current version in July of 2014. Yeah, almost exactly 100 years from WW1, maybe that jinxed it......
     
  8. DavidJ

    DavidJ Alibre Super User Staff Member

    I'm sure Max will post when this has been bottomed. Investigation is ongoing.

    One cause which has come to light for hidden lines to be visible when they shouldn't be, is the inclusion within an assembly of an imported part having such issues itself. The problem can then affect the display of the whole assembly. Put simply - a part which imports with display 'problems' which are not fatal, can affect the display of an assembly it is used in. Exactly why/how this happens hasn't been determined yet.

    This particular issue can be resolved by suppressing or removing the 'problem' part. Hopefully a re-import with different import options can result in a part that doesn't have the problems, and can then be used successfully in the assembly.
     
  9. JST

    JST Alibre Super User

    OK.

    I would like to point out that the suggested cause (defective parts) is probably NOT the case for at least the large model I presented, and I believe not for the smaller one that was posted here. In neither case was any component part changed in any way during the time that the display changed from bad to proper. Not on my system, anyway, cannot swear to others'.

    The SAME set of component parts simply changed from having transparency issues to displaying perfectly.

    As mentioned, the change was not immediate. The jaggies and stripes went away immediately when the isometric view was selected. However, the transparency issues persisted through several openings and closings of the models. The large model took perhaps 6 or 8 open/close cycles before it suddenly was good.

    At no time were the subassemblies that showed the transparency issues even so much as opened by themselves, let alone edited or changed out for different ones. Since the large model had subassemblies moved around, it was, of course, saved repeatedly. I cannot rule out some sort of "automatic self healing" process that may have occurred when the model was saved.

    The very same parts and assemblies that had the problems now display perfectly, with ambient occlusion on, etc. None of them were altered in any way between the "bad" display, and the "good" display.
     
  10. DavidJ

    DavidJ Alibre Super User Staff Member

    Calm down - I only mentioned that it was one cause that had come to light, and I only referred to hidden lines showing when they shouldn't.

    Great that you've checked and it doesn't apply in your case.
     
  11. JST

    JST Alibre Super User

    Perfectly calm, just want to be totally clear about what the circumstances are, so there is no confusion and no blurred lines.

    OK, the whole deal is becoming a bit irritating, I will admit that.

    I would imagine, however, that it is becoming a bit MORE irritating for the development team. Been there, seen that, and threw away the t-shirt. It usually is better when as many facts as possible are nailed down tight, because that often is of a great help in identifying the source of the issue.

    At the risk of telling grandma how to suck eggs, it might be wise to dig into some of the basic assumptions and math routines. There is a "constellation" of issues in the program, and it sure looks as if many things are potentially explainable, at least in part, by issues of rounding and significant digits.
     

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