Surface anomalies

Hi Support team!
I’ve been modeling kind of a vintage R. Royce from the 60’s. The car has lit. no straight lines wherever you look. I began modeling the rear side of the car: soft edges and slightly curved surfaces. I really find it very hard to model it since there’s a surface that is not well defined, poor CV Layout and zebra stripes…
And, apparently there nothing i can do for surface improvement.

please open the 3dm. file and toggle on the zebras and emaps.

is there any method i could employ for surface improvement?
is the general surface layout well designed?

mcNeelSample.3dm (336.5 KB)

thank you…

that surface is highlighted in red, the one that requires improvement.
thx again!

cant say your layout is particularly bad its simple and can sure be facilitated to become perfect surfaces. still you seemed to have messed something up in this area, when i join it leaves a naked edge, which is most likely part of your messed up zebra.

Hello - I think I’d at least try making the side panel as all one surface - at least there at the rear where you have is as three - and trim that sharpish corner shape at the trailing edge rather than try to build the surface edge to edge.

As is, with the three surface layout, I’d do this:
Make the transition surface a blend surface with History.
Make some vertical lines in Front and project these onto the blend, with History, BringToFront and CurvatureGraph
You can see the anomalies more easily, along with Zebra of course.

I would also simplify the lower surface to degree 3 in U - just fewer points to manage.
Then, with MoveUVN and very small inncrements, or DragMode > ControlPolygon and DragStrength set low (25% say) make small adjustments to the upper and lower surface points and watch how they affect the curvature graph on the section lines - you want these graphs to be all ‘positive’ (not switching sides) and somewhat similar and progessive in shape. I tihnk you’ll have to accept that the outer edges where you already have some transition surfaces in place - maybe prematurely - will change slightly.

I moved some of the interior points in the upper surface along their control polygons outward, radially , a bit as well as normal.

mcNeelSample_Somewhat.3dm (185.8 KB)


thank you. Neat explanation and good info! I like it, nice zebras! thanks again

thanks for your reply. you’ve mentioned ‘perfect surfaces.’ whats that? do you know how to fix those naked edgess?

nothing less than you can imagine and more i hope.

if you simply just want to fix the naked edge you can sweep2 but looking now once more at what you produced, that will not help fixing that particular area very well in regards of continuity… at least not without having to rebuild the surrounding surfaces.

The cleanest result happens when that shape is made with a single surface that’s trimmed subsequently. I simply extended your original surface and did some control point adjustment.
Split this surface.3dm (280.1 KB)

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thank you for your reply! Clever idea but i dont like having complex srf edges. my idea is to build a single surface and adjust cv’s (without trimming) and then run the Join Command for srf Match. ill see if it works. have a nice day!