AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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*Ernst, Fred
Message 1 of 7 (197 Views)

Grading Targets

197 Views, 6 Replies
10-14-2003 11:13 AM
It says in the Grading Help that a target can be a feature line or the base
line of another Grading. How do you set these types of targets for a
Grading in the new interface? I do see the standard target options of
Distance, Surface and Elevations.

What I am hoping we will eventually have here is the ability to have the
Grading adjust the vertex elevations of a target line relative to the
baseline of the Grading to effect one's desired slope between the two. Or
vice versa, have the Grading adjust the baseline elevations relative to the
target line to achieve the desired slope between the two.

In LDD, I use the folded plane technique of grading, in order to extract
surface elevations at each breakline vertex of a meandering target line
relative to a baseline that the surface projection is created from. Of
course, I would like the new grading to do this in the background now.

Fred
*Albert, Glen
Message 2 of 7 (197 Views)

Re: Grading Targets

10-14-2003 09:28 PM in reply to: *Ernst, Fred
Fred,

That didn't make it into this preview release. That help file comment must
have been missed when we pulled it. ( Grading is the most incomplete
component in the preview. It got a later start then most, as it required
some of the other components to be working before much could be done and it
has some fairly complex issues to solve.)

When it gets implemented you will be able to grade to a feature line, a lot
line or an alignment. One criteria option will be to use the elevations of
the target so that the slopes will vary. There are also the criteria options
to grade by slope, elev or relative elev. These options will set the
elevations on the target feature.

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'm not sure that I understand the folded plane technique, could you
elaborate.
Thanks,

Glen Albert
Software Engineer
Autodesk Civil 3D Team


"Fred Ernst" wrote in message
news:9E15C9F9E054ED091BE6D4C121409586@in.WebX.maYIadrTaRb...
> It says in the Grading Help that a target can be a feature line or the
base
> line of another Grading. How do you set these types of targets for a
> Grading in the new interface? I do see the standard target options of
> Distance, Surface and Elevations.
>
> What I am hoping we will eventually have here is the ability to have the
> Grading adjust the vertex elevations of a target line relative to the
> baseline of the Grading to effect one's desired slope between the two. Or
> vice versa, have the Grading adjust the baseline elevations relative to
the
> target line to achieve the desired slope between the two.
>
> In LDD, I use the folded plane technique of grading, in order to extract
> surface elevations at each breakline vertex of a meandering target line
> relative to a baseline that the surface projection is created from. Of
> course, I would like the new grading to do this in the background now.
>
> Fred
>
>
*Ernst, Fred
Message 3 of 7 (197 Views)

Re:

10-14-2003 11:03 PM in reply to: *Ernst, Fred
Hi Glen,

I've inserted my comments 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.

>
> 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.

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...
>
> 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.

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.

Thanks,
Fred
*Albert, Glen
Message 4 of 7 (197 Views)

Re:

10-14-2003 11:56 PM in reply to: *Ernst, Fred
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
*Ernst, Fred
Message 5 of 7 (197 Views)

Re:

10-15-2003 12:47 AM in reply to: *Ernst, Fred
> 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.

Yes that will.

> 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.

Great.

>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).

Yes, exactly.


> Transition Regions aren't complete, but when they are they will support
what
> you are asking for.

Great.

> 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.

No radial would be fine, because mitered would create a crease where we
would need a pan to protect the asphalt. We would want to extend the pan for
cost reasons only to the point where we can't create that radial slope
condition for sheet flow.

> 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.;
>

Are you saying the Gradings will trim themselves automatically? That would
be great.

Another question: Can you add a radial region to the Grading object?

Example, say between the property line and the meandering walk , I want a
4:1 slope up from the property line, then break to a 10:1 slope to the walk.
You could do it with two Gradings and have them trim themselves, but it
would be nice to do it with one Grading. Now in LDD, you have to do it with
the High\Low Point routine to find the break location. I've actually written
a routine that finds the High\Low on a 3D Polyline using the endpoint
elevations. So now I draw all these perpendicular 3D polylines between the
baseline and target line, run my routine, and it places a new vertex at the
required gradebreak location and linearly adjusts the rest of the vertices
for each radial polyline. All of these radial polylines between the baseline
and target line look like a Grading object, just with a gradebreak somewhere
along them. Actually to have the capacity of 2-3 of these radial regions at
some point would be nice. You could just toggle them off if you don't want
to use them.

So in the end, will these Gradings adjust relative to each other based on
their established relationships if a change is executed on one? Will they
have to be in the same Grading Group, Site or both to change relative to
each other?

Thanks,
Fred
*Albert, Glen
Message 6 of 7 (197 Views)

Re:

10-15-2003 02:36 AM in reply to: *Ernst, Fred
Fred,

> Are you saying the Gradings will trim themselves automatically? That would
> be great.

Yes. Currently intersection trimming only works between gradings in the same
group but I think we'll need to expand it to optionally trim intersections
with gradings in other groups.

> Another question: Can you add a radial region to the Grading object?
>
> Example, say between the property line and the meandering walk , I want a
> 4:1 slope up from the property line, then break to a 10:1 slope to the
walk.
> You could do it with two Gradings and have them trim themselves, but it
> would be nice to do it with one Grading. Now in LDD, you have to do it
with
> the High\Low Point routine to find the break location. I've actually
written
> a routine that finds the High\Low on a 3D Polyline using the endpoint
> elevations. So now I draw all these perpendicular 3D polylines between the
> baseline and target line, run my routine, and it places a new vertex at
the
> required gradebreak location and linearly adjusts the rest of the vertices
> for each radial polyline. All of these radial polylines between the
baseline
> and target line look like a Grading object, just with a gradebreak
somewhere
> along them. Actually to have the capacity of 2-3 of these radial regions
at
> some point would be nice. You could just toggle them off if you don't want
> to use them.

Not with a single grading object. The approach we took was that you create
one grading from the walkway and one from the property line and if they
intersect they will create the high/low ridge feature line. Then, if either
the walkway or the property line is edited it will recalculate the high/low
intersection feature line.

But we should have the capability to more or less accomplish what you
describe at some point in the future. It requires some additional control to
feature line elevations. In particular, the ability to define a high/low
elevation point between two elevations on the feature line and have it
adjust if the elev at either end is edited, or if either grade is edited.

With that you would be able to draw your connecting perp lines as feature
lines, and on each one define the two grades that define the high point
location.

Within a site, all feature lines that have a common point will share the
elevation. What that means is, if you step along the base line and edit an
elevation, the radial line elevation will also change which would update the
location of the high point on that radial line (if and when the high/low
capability is added to feature lines).

In between the radial lines you would insert Fill gradings. I think I need a
better name for it because it could be confused with fill slopes, but a Fill
Grading is one that is not controlled by grading criteria. It is used to
fill in holes - areas that are completely bounded by feature lines.

> So in the end, will these Gradings adjust relative to each other based on
> their established relationships if a change is executed on one? Will they
> have to be in the same Grading Group, Site or both to change relative to
> each other?

Yes, if you edit the base line it will update all gradings that are attached
to it. Since you can grade from a resulting target line, those gradings will
update as well and it will ripple down to all connected gradings. It will
then recalculate the intersections and clean them up.

All related grading work has to be within one site.

Grading groups are named collections to make it easier to organize them and
do operations such as create surface. A grading can only be in one group,
but there is no restriction on how gradings are organized into groups.
Individual gradings can easly be moved to other groups as desired. The one
limitation is with the intersection cleanup. Gradings only clean up
intersections within the same group. I plan on adding an option to each
group to select which other groups you want it to intersect with.

Glen
*Ernst, Fred
Message 7 of 7 (197 Views)

Re:

10-15-2003 04:01 AM in reply to: *Ernst, Fred
That all sounds very much on the mark Glen. I would just end saying to make
all your hard work really viable, we need only two Feature\Base line linear
tools: 1) the High\Low we've talked about and, 2) Set Grade between two
vertices and linearly adjust all the vertices in between the two.

I've written both of these in VBA for 3D polylines. Each routine pops up a
dialog box with two Input boxes showing the endpoint elevations, an Input
Box showing the current 2D slope of the polyline (2 slope Input boxes for
the High\Low routine). By changing a value in one Input Box the others
update. Uneditable Label boxes show length, and on the High\Low routine,
distance to the gradebreak

I also use some of Dotsoft's polyline tools such as Proportional Slant,
where you can graphically pick the vertices you want to use for Start and
End, and then it linearly adjust the vertices that lie between. My tools
don't have the ability to pick internal Start and End vertices like Terry's.

At this point, I'm just afraid all your good work developing the Grading
relationships will be hamstrung by not being able to manipulate the
baselines\feature lines with these types of linear tools. We would have to
explode the feature line or Grading, manipulate with the linear tools, then
redefine all the relationships again.


Thanks,
Fred
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