Blender's solidify modifier

Discussion in 'Design and Modeling' started by HarryLister, Dec 3, 2012.

  1. HarryLister
    HarryLister New Member
    Hi, I just did my first model in blender and submitted it. It was rejected at first and I took a wild guess that it needed thickness and was right, but I dont really know the actual thickness I applied. I applied the default settings for solidify which have thickness of .01 and O of -1.00. I know the -1.00 means the thickness is added toward the inside, but what exactly is .01?

    I'm wondering if my model will be too thin, but dont know how to determine how thick it really is.
     
  2. Fredd
    Fredd New Member
    A simple technique , depending on the printed size you want, is to go to Scene where you can set units, None, Metric, or Imperial. The scale factor is under the unit choice, if Metric is chosen, .01 scale will change a unit to cm. If .001 with change it to mm. If you chose Imperial, setting scale to .0254 will make a unit an inch. With Metric chosen and the model scaled to the size you want, Apply Ctrl A(apply scale, then you can input the value into solidify mod(1mm thickness for example.). Interesting enough if you chose inches as the other option, you can still type in 1mm as the value, which will give the wall 1mm thickness.(or any other thickness you want.
    You can see the values in the N panel in inches, or cm for dimension value.
    What makes this simple, select all of your mesh, export as a dae(Collada). When you upload your mesh, SW detects the scene data. So your model will be printed in the dimensions of your bounding box values in the N panel. A .dae is one of the formats SW recognizes scene data on upload.

    To double check the thickness, you can turn on edge length in the N panel, and select an edge. Extra good stuff if you have the Measure panel addon, it can display volume in object mode, plus warn you if the model is nonmanifold. For all of the steps, remember if a model is scaled in object mode, use Apply scale(Ctrl A) after it done.

    An STL format is totally different..Chris Lowe has a good tut on it.

    Keith
     
  3. HarryLister
    HarryLister New Member
    Thanks I'll soak that in for future reference. I dont know why though I'm not seeing units as a choice anywhere. I'm using 2.60 if that matters.
     
  4. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    I know there is a way to set units, I just don't remember how that is. I just use the blender units as the unit I want to upload (usually inches) So I use the blender units, export stl or obj, and upload as inches.
     
  5. Fredd
    Fredd New Member
    You set it in Scene. Should be to the right of the Camera icon in upper right corner of screen.
     

    Attached Files:

    Last edited: Dec 4, 2012
  6. HarryLister
    HarryLister New Member
    Geeeezzzz, there it is clear as day. Thanks. I had it set to none and selected inches when I uploaded.

    As for the model, it got cancelled for wall thickness..
     
  7. HarryLister
    HarryLister New Member
    Finally, it got accepted with the new thickness but now solidify adds thickness to the outside and the price jumped 80%.
     
  8. Fredd
    Fredd New Member
    Lol, I think the thickness was .234 mm. Experiments are a pain. Volume(price) does have a tendency to increase exponentially when thickness is increased.

    Whenever I mention input a value while modelling , i.e. 1 mm , don't just type 1, type 1mm.
    The bounding box dimensions came in at 13.597 x 4.920 x 2.024 .

    Your model does have some mesh problems near the tapered end. Remove doubles(54 removed. In edit vertex select, deselect all, then select nonmanifold. The problem area should be apparent near that end.

    Keith
     
  9. HarryLister
    HarryLister New Member
    I think the tip end was starting to open up on itself. The thickness follows the curve I used and is making the sharp edge overlap. I wonder if I could apply thickness only to a certain region? If that is possible, then I can add thickness where it wont overlap and then bore holes.
     
  10. Fredd
    Fredd New Member
    Okay, maybe select the basic mesh before you added the solidify modifier. Flip all its normals inward. Now apply the solidify modifier. Flipping the normals inward causes it to expand, instead of contracting when you add a positive value for thickness.Click exact in modifier. It contracting as it normally does could be causing the problem
     
  11. HarryLister
    HarryLister New Member
    I tried the normals trick and it didnt work. If I convert the basic shape to a mesh from the start, it turns solid but I cant get that to follow a bezier. Solid would allow me to use boolean to bore holes.
     
  12. HarryLister
    HarryLister New Member
    I got it solid. I took a screen shot of the version which used beziers and used that as background image. Then I went in converted to a mesh and extruded it in steps and used sizing and rotate and grab to match the background image. Now I can bore holes and remove material to get the cost down hopefully.
     
  13. HarryLister
    HarryLister New Member
    That didnt work any better. When I extruded, only the first shape was solid. I poked holes in the extrusions and they were hollow. No big deal I guess except it means more work to close it. I'm going to try duplicate on the solid shape to see if that helps.
     
  14. Fredd
    Fredd New Member
    Here is an old technique that could work, http://wiki.blender.org/index.php/Doc:2.4/Tutorials/Modeling /Surfaces/Skinning. Duplicating the surface might possibly work. If you woudn't mind, do you have a blend file of the basic mesh before thickness was created, even the file using beziers, before turned to a mesh you could share?


    If you can somehow create an interior mesh, use Boolean difference to bore holes from the outside to the hollow mesh

    Keith
     
    Last edited: Dec 5, 2012
  15. HarryLister
    HarryLister New Member
    Interesting trick with the skiinning. I have another shape that's very boat hullish and could use that.

    For this one, I can get a surface and a mesh. The fun starts when I remove surface and then have to make faces over and over to close it up. The trailing edge has me concerned too because it comes to a knife edge and I'm thinking they could reject it for being less than minimum even though they didnt even mention that when they rejected the first..
     
  16. Fredd
    Fredd New Member
    When I listed that link, I left out something really important. You can use the technique with closed surface loops(airplane wings for example, fuselages). :)
     
  17. HarryLister
    HarryLister New Member
    A wing is what I'm trying to make. I'll give the skinning a try and see if I can get a smoother shape.
     
  18. HarryLister
    HarryLister New Member
    I got a wing I can live with. It's a mesh now, so maybe I can use boolean to get more holes.
     

    Attached Files:

  19. HarryLister
    HarryLister New Member
    The last attempt wont print because it gets too thin at the trailing edge of the wing and at the tip, so I used offset to try to get some thickness and I left the tip off. The price came down, but if they wont print it then whoopie.

    They tell me the size needs a minimum thickness of 2.07 mm. I dont know how to use netfabb to check.
     

    Attached Files:

  20. HarryLister
    HarryLister New Member
    I've done this model over about 100 times now. What I had to do was take the basic bezier(airfoil) and break it into a top and bottom. I noted the location of the control node vectors and used duplicate curve and then typed in the location of the key control nodes. The reason for the two curves was so I could open up the trailing edge and have it thick enough without the bottom trying to go through the top and yet have it thick enough. It seems right now, expensive but right.

    There's so much I need to learn about modeling, but if this prints I'll be pretty pleased.