Yes there is… if you understand how normal grading works and follow a method I came up with.
I will provide a basic leotard pattern I recently did using this method. Let’s assume we’re going to use a standard 2" grade, where each quarter get’s graded a total of 1/2".
What I do is trace out a pattern piece on paper, using an XY reference point… in the example I use the chest line and center front or back (fold). Then locating each “grade” point I measure the x and y distances relative to the 0 reference point. This is pretty much how one digitizes a pattern using a large drawing tablet. Now here’s where the trick comes… seeing as how Seamly2d does not have a normal grading method based on rules one sets up we have to have a way to set a grade rule in the formula of the points. Knowing the size of the pattern that was traced I know the chest, waist, and hip size the pattern fits… in the example it’s a 42 chest, 34 waist, and 44 hips … I can use those measurements to know how much each grade point has to move in/out or up/dn - they way I do this is using math trick of subtracting the chestscale (1/2 the chest) from the ChestsSale measurement from the Tape file… multiply this by the amount the point normally moves in a 2" grade… and add this to the x measurement from the tracing. For EX: Take the point BC_1 - on the tracing it’s 9 1/4"… the ChestScale of a size 42 is 21" , and the BC_1 point would move in/out a full 1/2" in a 2" grade. Here’s the formula for the point BC_1"
9.25+ ((@ChestScale-21)*0.5)
This is where the neat math comes into play… lets say you want to grade up 4" or to a 46 with a ChestScale of 23":
9.25+((23-21)*.5) = 10.25"… the point will now move out the 1" for the quarter and 4" total or 2 sizes up
OR let’s say we want to grade down 4" to a 38
9.25+((19-21) *.5) = 9.25+((-2) *.5) = 9.25+(-1) = 8.25… the point will now move in the 1" for the quarter and 4" total or 2 sizes down
Here’s the pattern file and 4 measurement files to play with.
Womens Leotard.val (19.5 KB)
Women_42.vit (4.2 KB)
Wolf_W_12.vit (4.2 KB)
Wolf_W_18.vit (4.2 KB)
Beth_48.vit (4.3 KB)