I have no idea how to draft this curved surface

[Weeve]

I've tried various combinations of loft (Sweep seemed useless, as there's a change in profile from start to finish), but can't seem to quite get any good results, that are anywhere near 'parametric' the closest results I've gotten was to make five different cross sections, and loft them all together, and cut off the bottom of the loft where the angles went goofy, and that's far from my ideal of an easily modifiable parametric design

Here is what I'm trying to draft, it's the head dress to the queen piece of Code Geass, I have the rest of the piece drafted with no problems:
http://www.animejackpot.com/blog/wp-con ... s-King.jpg
http://media1.giphy.com/media/VE4InmieSgVqM/giphy.gif

Some things to note about the design which are problematic:
The head is curved, and the head dress is supposed to start at the top, following that same curve
From a front view, the head dress is only curved for the top 1/3 or so of the model, then it's straight
From a side view, the curve starts out steep, then lengthens out to be a gentler curve, so the curve follows no natural logical transition

Is there some way I can make a front, side, and bottom profile(sketch?) and have a curve made between all three?

[mario52]

hi
sketch with Sketcher_CreateFillet
and revolve

(example)

I have no idea how to draft this curved surface.FCStd

(20.31 KiB) Downloaded 72 times

mario

[Weeve]

No, I mean the head dress, not the base of the chess piece, but that curved surface on the very top of the model, behind the 'head' of the queen piece, where her hair would be, the base was simple

[jeno]

I think thats was you are after.
It is made of two revolutions, one with full 360 degree and the second with 190 degree.
the "ears" are made with a wedge (part workbench -> create primitves -> wedge)
Couldn't upload the freecad-file with all the fillets because it is a bit too big.
So the attached one is without fillets.

[Weeve]

Using that method, you miss out on the curve along the back of the head, look at the gif when it's in a side view, there's an elliptical curve along the back, as well as the curve you used a rotation for, is also elliptical, since it's an elliptical curve on all three dimensions, rotations are fairly useless, that aside, making a 3D elliptical surface I can do, I just don't know how to make it match all the three profiles and evenly curve between them all

I feel that perhaps the images I have linked to have not accurately gotten the look of the model across, so I made the three profile sketches that I'm trying to find out how to make a curve along:


As you can see, all three curves are elliptical, and the front view profile changes from an elliptical shape at the top, to be straightened going towards the bottom, further complicating the process

[jeno]

Using that method, you miss out on the curve along the back of the head, look at the gif when it's in a side view, there's an elliptical curve along the back, as well as the curve you used a rotation for, is also elliptical, since it's an elliptical curve on all three dimensions, rotations are fairly useless, that aside, making a 3D elliptical surface I can do, I just don't know how to make it match all the three profiles and evenly curve between them all

If you already have drawn the three vertical profiles just make a sweep and you are done.

[Weeve]

I tried that, and I'm getting really weird results, it's not even seeming to sweep remotely close to along the path when I just use one of the sketches, and if I use two I get the error "ACCESS VIOLATION at address 0x00000008 during 'READ' opepration"

Edit: I found if I removed all the straight lines that made the sketches a closed loop, the results were closer, but I get the sketch moving out forward of the line, instead of pivoting where the two sketches intersect:

[jeno]

Hmm.. looks indeed a bit strange.
Can you please try the following: use the original made sketches. Move on all three the vertikal lines in the center a bit outwards so that they not in the centre anymore. Probably the problem is that the sweep is wrapped around itself. The oc-kernel is a bit sensitive with coplanar faces and probably also edges that are at the same place.

[Weeve]

I moved them out, and it looks like the problem is still the same, it looks like as it's going along the sweep, it's tweening the size of the shapes as it rotates, and that's moving the base of the sketch outwards, since the angle is moving steeper than the size change.

I'm really quite lost on this, and at this point I'm considering making the shape in a mesh editor, and importing it, I would lose the parametric advantage, but It's looking like it may be impossible.

[jeno]

I made a quick trial with 3 simple sketches and it worked like a charm.
If you don't mind please attach your fc-file and let's find out what went wrong.