curves

[Joe]

I'm having trouble having cg for windows drawing curves using cg points. When I go to the line routine and want to go aroung a curve with the three points, I can't figure out what order to put them. I have tried all sorts of ways(pt-pt etc..) NOTHING! What am I doing wrong?? Can you use any three points to draw a curve or does the coord file have to have the correct desc for the points?

[Jeff]

Joe I am not sure what you are trying to do there. The line routine works this way when you to get a point of curveature after selecting it
you need to indicate by se4lecting a check in the box for clockwise or counterclockwise and then pick the radius and then go onto the PT. This must be a geoetriclly correct curve or it willnot work.
If you are attempting automatted mapping the cammand is CF* or curve fit and it will make a curve based on an eyeball pc and pt and one shot on arc.

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[Joe]

Do the points in the coordinate file have to have the description like PT, or PC in order for the curve to work

[jeff]

Negative, in fact you do not want to use PT or PC an example from my field crews descrioptions would be:
BL*BC1 this means begin line back of curb #1 the letters tell it what layer to be on and what symbol to create the number tells it it is different from BC2 or BC3 ETC.
Next shot could be the eyeball pc ALONG THE BACK OF CURB and would be coded as follows:
CF*BC1
Next you need one point on arc sop the program can draw a spline line best fit around the curve so it be coded as follows:
BC1
At the eyeball pt you need to let it know you think the curve is ending so you code that as follows:
CF*BC1
iT WILL STILL HAVE TROUBLE DRAWING THE CURVE WITHOUT THE LAST TANGENT SO GO OUT THE TANGENT SOME AND TAKE ANOTHER SHOT coded as follows:
BC1
OK so far we have covered 2 of the four thingsd your field crew will have to know to do automatted mapping and of they are smart enough to work in the field they have absorbed that all ready,
BL* begins a line
CF* defines the ends of a curve
You still need to get two more codes into your heads to be a mapper they are:
CL* close line or draws a line back to the BL* that started that lione
EL* ends a line or staops it there even if you use that code again by accident, I normally dont use the EL* unless I have like a lot of culverts and dont feel like keeping track of the numbers