Simplification and reprojection

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  • Avatar
    chris

    you just need to re-run texturing stage.

    normally i don't run that until after the simplify stage.

    which makes the start button a bit pointless for me.

  • Avatar
    Götz Echtenacher

    Yeah, i never ever used it myself...  :-)

    alice, the weird "textures" you are seeing are actually vertex colous - the texture is lost with the simplification because the geometry changes and therefore the unwrap is useless.

  • Avatar
    Alice

    Thank you.

    When I click "Texture" again, it does give me textures back, but parts of them are blurry while the vertex colors looks absolutely great.

    What am I doing wrong here?

    Thank you.

     

  • Avatar
    Alice

    Can I send the image set somewhere so that the devs can give me suggestions how to fix this?

  • Avatar
    chris

    have a look at large triangle removal threshold. under unwrap settings. that should fix those blurry parts.

    though i also generally find that with rc the texture won't ever look as good on the low res model as the full high res one. 

     

  • Avatar
    Götz Echtenacher

    What chris says!

    Chris, that's interesting what you say about the texture quality with full res compared to a simplified one. I would have thought the opposite is the case since with high detail reconstruction the tris are probably close to the size of the texels. In my imagination it should be better to have larger surfaces with less gutter influence. But I am going to try it out your way. Is that the case also with normal reconstruction or only with high? The reason is probably the same as I speculated in Mike's thread https://support.capturingreality.com/hc/en-us/community/posts/360000190092-Modo-Users-Looking-for-help-with-UV-workflow-and-Export-Import?page=1#community_comment_360000068531.

    How is the time difference of texturing a full resolution mesh as opposed to a simplified one? I always thought a simplified one takes shorter, but I have heard people claim the opposite. How is this in your experience?

  • Avatar
    Alice

    Even when I set "Large triangle removal threshold" to "1", it always switches back to "10".

  • Avatar
    Götz Echtenacher

    That's probably because 10 is the lowest number. You should set it to 100 or even 1000!  :-)

    If you hover over the name in the menu, you get some info about what it does...

  • Avatar
    Alice

    Even 10.000 doesn't change anything.

    The textures are still as blurry as in my screenshot.

  • Avatar
    Götz Echtenacher

    Did you texture it again?

  • Avatar
    Alice

    Yes, I did.

  • Avatar
    Götz Echtenacher

    How much did you simplify? As in what was the original tri count and the one after the simplification?

    Is the vertex view (left) the same model as the textured view (right)? Or is the left one the original and the right one the simplified?

    Can you upload another screenshot of both models (before and after) but as a wireframe or solid view?

     

  • Avatar
    Alice

    How could I show the model as a wireframe or solid view?

    I didn't find the button for that.

  • Avatar
    Götz Echtenacher

    When 3D view is active (blue frame) then you can set quite a few settings on the Scene tab (blue).

    Is it possible that in your textured model Sweet is not available?

    That would be a possible solution for your main issue, in as that you don't actually see the texture due to memory limitations but only the vertex colours...

  • Avatar
    Alice

    Sweet mode is enabled and working.

    Here is a comparison between a 1k tris model and a 100k tris model:

    https://s9.postimg.org/g5iv9yihr/compare1.png 

    The reprojected textures on the 100k model look alright.

    Due to the geometry that I'm dealing with, I think even 1k tris is already very high since the blurred texture occurs on an almost flat surface, right?

    Specifically, I'm talking about this area:

     

  • Avatar
    Götz Echtenacher

    Ah, 1k is extremely low - what was the original tri count and which method did you use (preview - normal - high)?

    Also, I meant screenshots in solid and/or vertex mode, where one can see the density of the mesh. A bit larger woud also be practical...  :-)

  • Avatar
    Alice

    Did you see the image that I posted here?

    https://s9.postimg.org/g5iv9yihr/compare1.png

    When I display the vertex mode for the 1k tris model, it looks like this, is that really you wanted?

     

  • Avatar
    Alice

    Here is another one, more close-up.

  • Avatar
    Götz Echtenacher

    Oh, sorry - did not check the link!  :O

    From the view there I can confidently tell you that the 1k model is definitely far too much simplified. If you look at the top left corner of the masonry bit, you can see that the model is slightly chamfered where in reality it is more or less 90°. Also, the recess of the plaster is not at all shaped as it should be. The reason for the blurriness is that RC is trying to project the texture from the images onto a surface that does not exist like that in reality. From different angles you get different colours, hence the blurriness. If you definitely need such a low poly count, then you need to use external tools to recreate the geometry as closely to the original as possible.

  • Avatar
    Alice

    So you mean that RC is doing a bad job at simplification (RC introduces a ramp (where I drew the red circle)), and the blurry textures are because of that?

    If yes, is there no way to fix that in RC? I would like to stay in RC for the entire process if possible.

  • Avatar
    Alice

    Here is a screenshot that shows the wall from the side. I don't think the "ramp" is so much "angled" that it would explain the blurriness. What do you think? In fact, the geometry looks rather nice.

  • Avatar
    Götz Echtenacher

    I would bet my left hand that this is the cause!  :-)

    If you look at one of your comparisons, it's exactly the areas that deviate greatly from the original where it gets blurry.

    You can't blame RC with such an extreme simplification. There are some tools that would do a slightly better job, but there is a limit. Why don't you try 10k and see where that gets you?

  • Avatar
    Alice

    I don't think RC did a bad job on the simplification.

    It just confuses me that the textures in this area are blurry.

    This doesn't look understandable for me.

    Could this be a bug?

  • Avatar
    Alice

    Or perhaps a setting that just isn't right?

    The geometry looks really nice, I don't understand the blurriness.

  • Avatar
    Götz Echtenacher

    No, not a bug. Definitely!  :-)

    Why don't you export both models and load them both in CloudCompare or MeshLab and look at the differences.

    And DO try the 10k model - it will look better!

  • Avatar
    Alice

    10k does look a bit better but still blurred.

    What I don't understand is:

    The geometry of the real object and the model (full res) and the model (10k or 1k simplified) is nearly flat in the area that I drew a red circle on.

    It isn't so that the real object is highly detailled while the simplified version is much less detailled.

    However, after simplifying and unwrapped and re-texturing, the blurriness occurs.

    Why is that? What has changed?

     

     

  • Avatar
    Götz Echtenacher

    If you now do a 50 or 100k and those look even better, then there is a definite tendency...

    This is all I can come up with.

    Would be nice if you could upload the 10k (and following) in textured and solid view...

  • Avatar
    Alice

  • Avatar
    Alice

    This is the 10k model.

    I don't see much geometry change in the region that was blurry before.

    So my question would be: Why does a little change in geometry result in such a big difference (blurry texture vs. sharp texture)?

    And the next question would be: How can I work around this problem?

    Can the developers of RC also tell their opinion here?

    For completeness reasons, here is the 33mio tris model in solid mode:

    As one can see, both the 1k model and the 33mio tris model have a nearly flat surface. That's why I don't understand why the 1k model is blurry.

    Shouldn't RC be able to reproject the texture correctly?

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