When I go from a no waist to a contoured waist, should the shape of the back crotch change? That is the curve flattens out.
Using Classic in Pant Customiser
Anya
DSPro 8.3

This is complex and not a simple answer
The crotch shape MAY change from "no waist" to contoured shape because the waist level has changed on the default setting. The rise or crotch depth has been affected when the top of the waistband sits at natural waist- instead of the pant waist sitting at the top of the waist.

The pant portion has dropped by the width of the waistband which at default is 1.5 inches.

You can uncheck Wast level at top in the complete pant designer in order for the band to sit above the natural waist which retains the same crotch depth.

When your crotch depth/crotch lengths are right at that critical set of numbers where the "other" choice breaks it- adjust crotch lengths. Always , ALWAYS reset the extensions and cbwd to zero when you make changes to any pant measurements so the program isnt working with bad data and can recompute what's needed.

So you have choices- adjust the crotch lengths for a no waist pant or for a with waistband pant. or reset the waist level position.

For better than 90% of our users the program recomputes this accuratly- but if your numbers are right in that "borderline" window - its pushing it. Your current No waistband numbers for crotch lengths may be just a tad short/long- increase or reduce by a 1/4 inch or so may rebalance the curves. In your case just the back it seems.

Kaaren

Thanks Kaaren, I was starting to think the curve was warping because I was staying up to late.
Anya

I lengthened the back crotch and got a nice curve, however the waistband of the front and back had almost a difference of an inch in width. It seems the flattened back crotch curve (ski jump) had to do with my 2.5" back waist dart. Put thatCBD to 0 and the nice curve came back. Yes we're dealing with a round behind.
I went to a square waistband, top at natural waist and it all looks good. However I'm rather curious about one thing more. I seem to have to draft 2.5" back waist dart and the program only computes 1/4" darts (two back darts on each side. Should I be adding more to those darts and less to the center waist dart? It fits pretty good with the darts I have, but I can't go to the contoured waist.
Anya

Ok this gets longish- when you have a high round bottom and rather extreme differences between waist and hip you need a lot of darting.

The center back waist dart and the side seam shapping are the major players in this shaping.
the two back waist darts carry a smaller portion of the distribution.

The fact is you want to spread the darting to as many places as possible:

2 back waist darts per side, a center back waist dart and side seam shaping gives the maximum amount of shaping "points"

the contoured waistband also has some horizontal dart "points" as does the back yoke.

Some folks with rather extreme dartings requirements should NOT use the contoured band-

Some folks with rather extreme shaping should NOT use the lowered waist levels.

Our side seams are based on bezier curves - a start and end point and a mid point.

The waist to hip of a natural waist is generally between 7-8 inches (give or take a little) a lowered waist shrinks in length first due to the waist band width and added to that the depth of the lowered postiion- mid or low) again decreases that distance from 'waist" to hip.. forcing a more extreme curve- see the simple rough graphic attached.


What happens when you over extend the darts take up is the fabric below it will pull off grain and swirl. so you need to spread the wealth so to speak without over doing it at any one place.

Surprisingly a trick is to slightly increase the thigh ease- which reduces the tension of the bend on the lower portion of the ebzier curve - the graphic is pre smoothing- it just shows what happens when you compress the distance between the start point ( waist) and the wider of abd or hip.

Kaaren

waist_hip_curve.gif (3 Kb, 26 downloads) side seam curve