Sunday, October 19, 2014


It's time we got the pumpkin bulges going.  I had a pumpkin dome last year, but I want to try rebuilding it from scratch with a slightly different approach.

I call this my "pumpkin slice rig".  Basically we build the wedge again, but this time as a rig.  It's a point world revolve from plus 20 to minus 20.  Make it glass and untick "visible".  Now it's a rig.

I made a new subcategory of mass called "construction lines" and set them to red.  I can use model lines for construction because we aren't going to use them directly in any "create form" operations.

Create radiating lines in sets of 3.  These will host profiles, each based on 6 points.  Effectively cross sections through the outer shell of the dome/egg.

Two points define the middle of the curve, hosted on the middle red line.  One at the end, the other set in a fixed distance.  The NCP for this second parameter is reset to "segment length". And controlled by a parameter called "thickness".

I don't know why I started to build a bowl, when it's supposed to be a dome. No big deal, just had to rehost the end points onto the upper curve.  To create the bulge, the points on the two side spokes have to be pushed further in.  So I have another length parameter called "curve".  Add "curve" and "thickness" together to set the position of the inner side points (CT).

When you are happy with everything, set the red lines to not be visible.  Leave it to the end because they will grey out.

At this point I just loaded the family directly into the project and made a circular array.  Wanted to check it out before attempting the furter complications of nesting and repeaters.

Set up a view from the indside.  Looks a bit bare perhaps, not sure what I can do about that.  I decided to make the dome white. Going for something of a tent effect.

Something tricky was going on with the array.  Not sure why.  I identified a reference point that had not picked up its NCP parameter correctly, but that didn't fix the issue entirely.

I decided to move right along to the next stage: a nested repeater dome ...  using the double nesting trick again.  Mass into GMA into mass repeater.  There's probably a better way, but for now this did the job.

All the funny alignments went away.  Maybe mass families just work better with repeaters than with vanilla style manipulations within the project environment.  I'll keep an open mind on that one.

I added a rib down one edge of the dome segment family, with a radius parameter that bounces down all the way to the project.

I also decided to try rotating the dome so the seams line up with the lift towers.  That seemed to work and set me off on adding a bit of articulation to the cores.  A vertical groove and an egg-shaped finial.

I'm happy now.  The concept is hanging together.  The connection to Boullee is there, but we have a genuine pumpking, complete with bulge factors.  There is a definite middle eastern feel, but also modern.  Perhaps a hint of sci-fi even.

I wanted to try an lattice texture on the cresent-shaped faces of the base, but this proved a little difficult.  You can get curtain panels to cut nicely at the edges in the nested families,

but by the time they come through to the project they are spilling over the edges.

The compromise for the moment is to set the edges to "empty".  Which it is for my final render for this post.  The variation in texture is definitely worth having.

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