Not quite what the tutorial is showing

  • Timothy

    Timothy - 2012-01-07

    Ref: BRL-CAD 7.20.2, Windows XP SP3


    I've been working on the tutorial at INSTALLPATH/BRLCAD 7.20.2/share/brlcad/7.20.2/html/lessons/en/mged11_refining_mug.html.

    The mug looks like:

    What I put into the GUI was:

    mged> in bodyout.s rcc 0 0 0 0 0 3.5 1.75
    mged> in bodyin.s rcc 0 0 0.25 0 0 3.5 1.5
    mged> in handle.s eto 0 2.5 1.75 1 0 0
    Enter radius of revolution, r: 1.45
    Enter X, Y, Z, of vector C: .6 0 0
    Enter magnitude of elliptical semi-minor axis, d: 0.2
    mged> comb body.c u bodyout.s - bodyin.s
    mged> comb handle.c u handle.s - bodyout.s
    mged> r mug.r u body.c u handle.c
    Defaulting item number to 1001
    Creating region id=1000, air=0, GIFTmaterial=1, los=100

    mged> mater mug.r plastic 32 128 32 0
    Raytrace complete.
    Raytrace complete.
    mged> mater mug.r
    Current shader string = plastic
    Specify shader.  Enclose spaces within quotes.  E.g., "light invisible=1"
    Shader? ('del' to delete, '.' to skip) 32 128 32 0
    Current inheritance = 0: lower nodes (towards leaves) override
    Should this object's shader override lower nodes? ( or '.' to skip) N
    Raytrace complete.
    mged> in rim.s tor 0 0 3.5 0 0 1 1.625 0.125
    Raytrace complete.

    Can someone suggest what it is that has not caused the mug to go green and why is the inner cylinder higher?

    Many Thanks,


  • Sean Morrison

    Sean Morrison - 2012-01-07

    Nothing major but looks like you missed a step or two and made a mistake in another.  The tutorial has you run the 'Z' command to remove your individual pieces from the display before raytracing just the mug region ("draw mug.r" after "Z" to redisplay the mug region).  In your rendering, you're still displaying everything including the mug.r region that you created but also the handle.c and body.c combinations and even the bodyout.s, bodyin.s, and handle.s primitive shape objects.  The inner cylinder that goes higher is the bodyin.s piece you used to subtract from bodyout.s.  So that's one error.  If you run the "who" command, you'd see a list of what objects are being displayed.  For the rendering, you just want the final mug.r object and not all of it's constituent pieces.

    The second issue I notice is that you ran the mater command twice.  The first time, it looks like you fed it parameters in the right order but then you ran it again and changed the shader from "plastic" to "32".  When you run the "mater" command without any parameters and it's prompting you individually, you want the "Shader?" response to be "plastic" then it'll prompt for red/green/blue color values and the inheritance flag.

    So to get it to display correctly, you need to "Z", "draw mug.r", re-run the mater command on your mug.r object, and then it should render correctly.  Hope that helps clear some things up.


  • Timothy

    Timothy - 2012-01-15


    Thanks for your advice.  It now looks a treat!




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