Fred,
See below ;
> > One criteria option will be to use the elevations of
> > the target so that the slopes will vary.
>
> Actually, we have slope criteria to meet, and need to change elevations
of
> the feature line or the baseline as we move through the grading of the
site.
>
Grading from the baseline to the target feature line at a slope will be one
of the options. The elevations on the target feature line will be determined
by the slope coming from the elevations on the base line. So that should
meet your needs there.
> >
> > The reverse isn't in the spec. Grading control always goes from the base
> > line to the target line. I'll add to to the wish list. I might be able
to
> > come up with an edit command that would allow you to edit the target
line
> > and adjust the base line elevations for certain types of criteria. For
> > example, slope to a distance would be possible but slope to a surface
> > wouldn't be.
>
> I say "slope to a feature line target" is what we need. The ability to
> adjust the feature line elevations while holding the baseline elevations,
> and vice versa, holding the feature line elevations and adjusting the
> baseline elevations to achieve the desired slope between the two.
Editing the baseline elevations and having it adjust the target feature line
elevations is easy and will be supported. The reverse is what I've added to
the wish list. I think I can come up with an edit option to do this, editing
the target feature line to adjust the elevations of the base line. It would
only be able to work with grading where the target doesn't move when editing
elevations - that is grading to a distance or feature ( feature line, lot
line, alignment).
> Still need Regions also, for example, Region 1: 10:1 slope between the
> feature target and base for 50' along the baseline; then Region 2:, 4:1
> slope slope between the feature target and base for 125' along the
> baseline,; etc., etc...
Transition Regions aren't complete, but when they are they will support what
you are asking for.
> >
> > I'm not sure that I understand the folded plane technique, could you
> > elaborate.
>
> Sure. Say you have a commercial parking lot, and you have a valley pan
going
> down the middle. All around the perimeter of this parking lot you have a
> meandering, sinuous, outfall curb and gutter. Now you want the flowline
> elevations of that curb and gutter to be everywhere 2% from the valley pan
> axis. So, using the 3D polyline of the of the valley pan axis, create 2
> breaklines on either side of it at 2% out past the parking lot perimeter,
to
> create a large folded surface that fully encompasses the parking lot's
curb
> and gutter. Turn the curb and gutter into a 3D polyline and extract
surface
> elevations from the folded surface into the 3D polylines vertices.
With grading to a target feature line you will be able to do this, but there
will be issues we'll need to sort out. In particular, grading beyond the
ends of the valley pan baseline.
Here is a simple example;
You have a rectangle that represents the parking lot perimeter, from 0,0
to 100, 50 (x,y). The base line runs from 25,25 to 75,25. If you grade from
the base line at 2% to the parking perimiter. Grading to the lower side of
the base line it will intersect the curb from 25,0 to 75,0 and grading above
the base line will intersect from 25,100 to 75,100.
It would be easy for me to project 2% radially from the ends of the baseline
to intersect the target at the ends but I don't think that's the way you
would want it to work. I would assume that you are looking for more of a
mitered corner affect with the flow direction prependicular from the
rectangle edges.
> Another example, say you have a property line where you need to hold
> existing elevations. Then you have a meandering feature line upslope from
> this inside your property, maybe an edge of walk. Now you want a 4:1 slope
> everywhere between the property line and the edge of walk. So using Create
> Curb, you offset that 3D polyline representing the property line
elevations
> at 4:1, and some distance past the edge of walk, create the surface, then
> extract the edge of walk elevations.
>
> I use this techinque all over a site to establish the desired slope
> relationships between "baselines" and "target lines". Now, I hope the new
> Grading will save me the steps of creating these surfaces used for
elevation
> extraction.
>
You will be able to grade from the property line to the edge of walk at 4:1
so that the walk way elevations are determined by the slope from the
existing elevation at the prop line. Another method, if you are trying to
set a specific profile to the walk would be to grade a sufficient distance
from the walk toward the property line (say @ -6%), then grade up from the
property line to distance beyond the walkway. If they intersect, the
gradings will get trimmed and you will get a feature line in between the
property line and the walk way where the gradings meet.;
Glen