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My Rendered Chair Has Flats

laststand6522732laststand6522732 Posts: 866
in Daz Studio Discussion

Why does my chair have these flats?  I've not seen this behavior before.  Is there anything easy I can do to fix it? anything hard?

Thanks...

 

chair.jpg
624 x 652 - 53K

Comments

  • hphoenixhphoenix Posts: 1,335

    In 3D, we call that 'faceting', i.e., the facets of the geometry are showing up as edges.  It usually means the material/shader you have on it isn't a smooth shading material.  It can also mean that the object's normals aren't correctly calculated, or that the individual quads/triangles (facets) aren't joined together.

    Is this an object you modelled yourself?

    If so, you may need to apply 'smooth' shading characteristics so that the modelling program knows to treat the facets as a smooth continuous surface.

    We'd need to know more about the object itself (what it was modelled in, what format the file is, what shaders are being used, etc.) before we could be more specific on how to fix it.....

     

  • mjc1016mjc1016 Posts: 15,001

    I can tell that it won't smooth very well, at least at the default smoothing angle. 

  • laststand6522732laststand6522732 Posts: 866
    edited January 2017
    hphoenix said:

    In 3D, we call that 'faceting', i.e., the facets of the geometry are showing up as edges.  It usually means the material/shader you have on it isn't a smooth shading material.  It can also mean that the object's normals aren't correctly calculated, or that the individual quads/triangles (facets) aren't joined together.

    Is this an object you modelled yourself?

    If so, you may need to apply 'smooth' shading characteristics so that the modelling program knows to treat the facets as a smooth continuous surface.

    We'd need to know more about the object itself (what it was modelled in, what format the file is, what shaders are being used, etc.) before we could be more specific on how to fix it.....

     

    I didn't model it, I can't do that yet.  It's a PP2 model from an old Poser set.  It *might* be c2005. 

    ..................................................

    When you're right, you're right!  I put an Iray wood shader on it, and it fixed it both in Iray and Open GL!  Now I need to fool with it for a while...

    Thanks!

    ...........................

    I only had a couple of shaders that worked.  I used Iray Walnut Semi-Gloss.  It still looked a bit funky.  A setting called "Coat Roughness" had the most positive effect.  Now it's usable.  It's not great, if it gets too glossy it will show facets, but it's usable.  I'm wondering...would we create the model differently today than we did 10+ years ago?

    Post edited by laststand6522732 on
  • RodrijRodrij Posts: 156
    edited January 2017

    Check if Smooth is ON in surfaces under surfaces.

    You can also try adding subdivision surface by selecting object then right clicking scene TAB>edit>Geometry>Convert to Subd. Go to Parameters with object selected > Mesh resolution > Subdivision Algorithm Catmark or experiment with Edge interpolation and subdivision Algorithm.

    You can also try adding smooth modifier by selecting object then right clicking scene TAB>edit>Geometry>Apply Smoothing modifier. Then in parameters under Mesh Smoothing Enable Smoothin On, set at least smoothing iteration 1 and choose a smoothing type.

    Post edited by Rodrij on
  • laststand6522732laststand6522732 Posts: 866
    Rodrij said:

    Check if Smooth is ON in surfaces under surfaces.

    You can also try adding subdivision surface by selecting object then right clicking scene TAB>edit>Geometry>Convert to Subd. Go to Parameters with object selected > Mesh resolution > Subdivision Algorithm Catmark or experiment with Edge interpolation and subdivision Algorithm.

    You can also try adding smooth modifier by selecting object then right clicking scene TAB>edit>Geometry>Apply Smoothing modifier. Then in parameters under Mesh Smoothing Enable Smoothin On, set at least smoothing iteration 1 and choose a smoothing type.

    Smooth was on.  It looked the same on or off.  Angle had no effect.  SubDs did not fix it. 

    I ended up using the Iray Walnut shader, then putting the original Diff map back in.  I took the occasion to experiment with the Diff bitmap.  Note that the original chair had the bitmap turned 90 deg.  I made it bigger too, by mirroring it first horizontally then vertically.  This helped me develop an appreciation for the word "seamless."  The day will come when I make this chair myself.  That's the only way I'll develop a complete understanding of what's going on here.

    The fixed chair is blond, I can't get that golden color in spite of the bitmap image color.  I can't get any gloss out of it either.  However, it's not an eyesore anymore.  Thanks.

    chair iray 2.jpg
    624 x 624 - 56K
  • hphoenixhphoenix Posts: 1,335
    Rottenham said:
    Rodrij said:

    Check if Smooth is ON in surfaces under surfaces.

    You can also try adding subdivision surface by selecting object then right clicking scene TAB>edit>Geometry>Convert to Subd. Go to Parameters with object selected > Mesh resolution > Subdivision Algorithm Catmark or experiment with Edge interpolation and subdivision Algorithm.

    You can also try adding smooth modifier by selecting object then right clicking scene TAB>edit>Geometry>Apply Smoothing modifier. Then in parameters under Mesh Smoothing Enable Smoothin On, set at least smoothing iteration 1 and choose a smoothing type.

    Smooth was on.  It looked the same on or off.  Angle had no effect.  SubDs did not fix it. 

    I ended up using the Iray Walnut shader, then putting the original Diff map back in.  I took the occasion to experiment with the Diff bitmap.  Note that the original chair had the bitmap turned 90 deg.  I made it bigger too, by mirroring it first horizontally then vertically.  This helped me develop an appreciation for the word "seamless."  The day will come when I make this chair myself.  That's the only way I'll develop a complete understanding of what's going on here.

    The fixed chair is blond, I can't get that golden color in spite of the bitmap image color.  I can't get any gloss out of it either.  However, it's not an eyesore anymore.  Thanks.

    If smooth was on, and angle had no effect, then the model is either (a) poorly modelled, or (b) so old it had face normals instead of vertex normals, so when it converted each face was brought in separately.  Which is NOT how most 3D programs expect things nowadays.  So yes, if it was a VERY old model, it is possible it never got corrected, and just remained a faceted model.  Ah, the good-ol-days of flat-shading and old Z-buffer render algorithms......

     

  • laststand6522732laststand6522732 Posts: 866
    edited January 2017
    hphoenix said:

    So yes, if it was a VERY old model, it is possible it never got corrected, and just remained a faceted model.  Ah, the good-ol-days of flat-shading and old Z-buffer render algorithms......

    Below, in Blender, the chair displayed in Solid mode.  The facets show plainly.

     

    chair facets.png
    430 x 552 - 39K
    Post edited by laststand6522732 on
  • hphoenixhphoenix Posts: 1,335
    edited January 2017
    Rottenham said:
    hphoenix said:

    So yes, if it was a VERY old model, it is possible it never got corrected, and just remained a faceted model.  Ah, the good-ol-days of flat-shading and old Z-buffer render algorithms......

    Below, in Blender, the chair displayed in Solid mode.  The facets show plainly.

     

    Looking at that screengrab, there are a lot of issues with that model.  The lower legs clearly show normals that are flipped wrong, the faceting should be smoothed (assuming you have the blender viewport in the right display mode) and quite a few iffy triangles.

    If I could get a hold of the model, I could probably fix the issues.  Would take a few hours.  Don't know if it has UV coords, I'd have to join all the triangles, unify the normal directions, and get smoothing properly working.  Then re-export it.  A lot of work for a chair I could probably find a very close match of for free that already works right.

    edit:  Found this http://3dsky.org/3dmodels/show/french_heritage_4 in a few minutes.  Free, there's an FBX file.  A bit high-poly, but could be decimated down a bit.  There were at least two other free ones on the site.  And that was just that site.

     

    Post edited by hphoenix on
  • laststand6522732laststand6522732 Posts: 866
    hphoenix said:
    Rottenham said:
    hphoenix said:

    So yes, if it was a VERY old model, it is possible it never got corrected, and just remained a faceted model.  Ah, the good-ol-days of flat-shading and old Z-buffer render algorithms......

    Below, in Blender, the chair displayed in Solid mode.  The facets show plainly.

     

    Looking at that screengrab, there are a lot of issues with that model.  The lower legs clearly show normals that are flipped wrong, the faceting should be smoothed (assuming you have the blender viewport in the right display mode) and quite a few iffy triangles.

    If I could get a hold of the model, I could probably fix the issues.  Would take a few hours.  Don't know if it has UV coords, I'd have to join all the triangles, unify the normal directions, and get smoothing properly working.  Then re-export it.  A lot of work for a chair I could probably find a very close match of for free that already works right.

     

    For now I'll fake it with lighting and shaders.  I resolve that in 2017 I will learn my way around modeling a bit.  I want to improve my ability to spot and diagnose things like this.  I'm just at the beginning of knowing that something is wrong.

    Thanks for your help.

  • laststand6522732laststand6522732 Posts: 866
    hphoenix said:

    edit:  Found this http://3dsky.org/3dmodels/show/french_heritage_4 in a few minutes.  Free, there's an FBX file.  A bit high-poly, but could be decimated down a bit.  There were at least two other free ones on the site.  And that was just that site.

    Yes...I need to broaden my searches for models.
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