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*Steve Cannon
Message 21 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 08:23 AM in reply to: *Brian Hailey
James, The popular belief is that Texas does indeed have mountains. But that is only because the New Mexico mountains are so high you can see they from west Texas. Don't tread on us (just come here and spend your money)! sc "James Wedding" wrote in message news:4051d21b$1_3@newsprd01... > Steve, > I didn't mean to belittle your requirements, by any means. We have to be > nice to New Mexico, it's the next county in Texas.
*Dave Simeone
Message 22 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 08:44 AM in reply to: *Brian Hailey
Hi Steve - I guess the real question relates to working with 3D arcs/splines (including parabolic vertical curves). What I was referring to in the tessellation is as follows: LDT/Civil Design grading - create a curve that you want to grade in Civil Design. When you grade this object the program has a setting that defines the increment that grading projections will be created along the arc. A small increment is more accurate, but higher in overhead. I would imagine that you want to keep the 3D geometry (almost like a mechanical part) that you shape with 3D offsets based on the exact 3D geometry. Specifically I am talking about modeling an alignment that has a parabolic curve. DAS "Steve Cannon" wrote in message news:4051e260$1_1@newsprd01... > Dave, I had to re-read your post several times to try and understand exactly > what you are asking: > > >Historically we've generally "accepted" the tessalation (tessellation?) > >of 3D vertical curves ... when working from a grading feature line. > > Laurie seem to assume you were talking about the parabola in a profile > view - and if this is the case, I am comfortable with the status quo > graphical representation. However, it sounds to me you are talking about > the sampling increment of 'Z' data to be placed in a potential grading > feature line. Historically, I did know that either LDT or C3D had any > routines that did this. The LDT 'Superimpose' profiles is the only existing > AutoDesk routine that I know that samples a profile at an increment. If > this is in indeed what you are asking - it scares me to think about the > direction you might be heading! > > Background: Within LDT, we have written our own 3Dpoly to Profile and > Profile to 3Dpoly routines. In going from Profile to poly we sample at all > critical points: PI's, PC's and PT's in the XY alignment. We sample all > PVI's locations from the profile. The routine requires a horizontal curve > sampling factor and a vertical curve sampling factor that are independent - > because of the nature of the mathematics. We make it user selectable - but > more often than not we will use a 0.5' foot horizontal sample through a > vertical curve and a mid-ordinate distance sampling criteria for horizontal > curves of 0.05'. This can result in a large number of 3dpolyline vertices. > The resultant 'tessellation' seems to be pretty good for terrain surface > creation, but here are the other design problems we encounter with this > approach: > > - The large number of closely spaced vertices can make grip editing and > critical point location tough to id in plan view. > > - A 3d object looses 2d characteristics - for example you can no longer > query horizontal curve from the object. > > - Plan lengths are replaced with True lengths on the object. Stationing is > lost. Neither AutoCAD nor LDT provide easy to use tools for plan queries of > 3d AutoCAD objects. > > - The large number of vertices make it difficult to locate true slope > breaks. > > - For all the above reasons the designer needs keep two layers of segregated > design data - one for plan work and one for 3d design work. > > It would be my hope that C3D did not go down the same path. As I sit here > and type, I see that Doug just now expressed my very concern in his reply to > Laurie above: > > > I think we should be able to have an interactive string element which has > > its horizontal geometry defined with horizontal tangents and arcs and its > > vertical geometry defined by tangents and vertical curves that designers > are > > familiar with but which displays the resulting 3D polyline as a feature or > > property of that object ... > > This 'string' element could potentially be an alignment. It 'handles' > horizontal manipulation. The present C3D problem I see is that the profile > is not a property of the alignment, but instead an independent object. If > the profile was a property of an alignment, whereby the user could > right-click on an alignment and manipulate the 3d elements of the alignment > by both graphical (profile) and tabular (sta-elev-pvi) means, we have the > starting structure for the string object. If I queried a location in plan > view along the alignment, I should also be able to get the vertical (z) spot > data. If I 'snapped' to any location along the alignment I would also snap > to the z coordinate, which is retrieved from the profile property. If you > gave me plan tools, whereby I could change the elevation of a spot location > on the alignment, that elevation would reflect in the profile property. If > you gave me a tool to interpolate a slope between two horizontal vertices on > the alignment, it would reflect in the profile property. There should be no > reason I couldn't add a vertical curve in plan view. I could see a full > range of interactive site design tools that allow you to modify a point in > plan view based upon slope, grade, or vertical distance from other 3dobjects > in the drawing. You could even have a routine similar to the LDT 'Curb' > routine: pick the alignment, an offset distance (horiz) and offset distance > (vert) that created a new OFFSET Alignment (say L1) and OFFSET profile that > was based on the main CL stationing. OFFSET alignments also have their own > associated profile property that could be manipulated after the offset. For > that matter, the horizontal alignment could also be post manipulated with > grips or whatever, while interpolating new 3d(profiles) by stretching or > extrapolating. > > And of course, they key to real productivity is that the alignment can be > used as a feature line for grading objects. As such, the alignment-feature > line keeps its plan and profile features, and any tessellation required for > tin creation is kept in the background and not even seen by the designer. > Horizontal curves still appear as smooth arcs. Grips remain on the alignment > only at critical stations. The programmers should be able to come up with > internal algorithms for sampling such as mid-ordinate for horizontal curves, > and a similar property for vertical parabolas based upon algebraic > difference in slope and length of vertical curve. Never bother the designer > with having to make tessellation sampling decisions - it should all be > transparent to him. > > sc > ----- Original Message ----- > From: Dave Simeone > Newsgroups: autodesk.civil3d > Sent: Thursday, March 11, 2004 5:09 PM > Subject: Re: Civil3D 2005 > > > Excellent feedback. > > Q - Historically we've generally "accepted" the tessalation of 3D vertical > curves (ie, break the geometry into short segments) when working from a > grading feature line. I'm guessing that ya'll - (I'm trying to learn to > speak in Wedding's language - I've got "Ya'll" and "All y'all" down pretty > nicely) - would like a smooth 3D spline. What is the requirement? The > smoother the better? Engineers go to great lengths to have accurate > vertical > (profile) geometry. I'm guessing that the true 3D geometry should be > carried > through the grading of the EOP, Kerb (how's that all y'all Aussies?), etc > geometry. > > Thanks > DAS > >
*James Wedding
Message 23 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 09:11 AM in reply to: *Brian Hailey
The Deck House, not the Landing! Wrong place.MMMMm breakfast burritos. -- James Wedding, P.E. IT Manager Jones & Boyd, Inc. Dallas, TX XP/1 on P4-1.6/512 LDT2004+C3D
*James Wedding
Message 24 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 09:13 AM in reply to: *Brian Hailey
>(just come here and spend your money)! Do you know how BAD I want to do that? I went to school in Lubbock, and loved NOTHING more than ditching class to drive to Ruidoso on Friday, getting up for breakfast at Deck House, skiing 'til my knees were shot, dinner at Casa Blanca (?) and driving home on Sunday. My wife gets all wistful anytime we think about those great trips. It's just not feasible from Dallas. This is a great thread, sorry to hijack it for my roll down memory lane! Delete at will, Anne. :-P -- James Wedding, P.E. IT Manager Jones & Boyd, Inc. Dallas, TX XP/1 on P4-1.6/512 LDT2004+C3D
*Steve Cannon
Message 25 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 09:32 AM in reply to: *Brian Hailey
sneaking in one last one ahead of the chainsaw... Ruidoso is nothing but bunny hills. No respectable snow snake would be caught in terrain that flat. Go to Taos for more challenging skiing - wait a minute, we stopped going there because all you see on the slopes is Texans. Try Los Alamos for an out-of-the-way but delightfully challenging experience. Stop at Sadies in Albuquerque for the real-deal carne-adovada sc
*Steve Cannon
Message 26 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 10:36 AM in reply to: *Brian Hailey
Dave, I guess my condensed version from the previous post is that the sampling increment depends on what the resultant object is to be used for. If it, or the resultant surface is going to be used for TC labeling, the vertical curve sampling needs to be much shorter (tighter) than the sampling increment along a horizontal curve. This is because we need TC elevations to within 0.01'. But we do not need the whole alignment sampled at that increment - horizontal curve sampling should be independent of vertical curve sampling. If the resultant object is just intended for earthwork, then we can get by with a much longer (looser) sampling increment through the vertical curve (vertical +/- 0.1'). sc "Dave Simeone" wrote in message news:4051e90b$1_2@newsprd01... > > Hi Steve - I guess the real question relates to working with 3D arcs/splines > (including parabolic vertical curves). What I was referring to in the > tessellation is as follows: > > LDT/Civil Design grading - create a curve that you want to grade in Civil > Design. When you grade this object the program has a setting that defines > the increment that grading projections will be created along the arc. A > small increment is more accurate, but higher in overhead. > > I would imagine that you want to keep the 3D geometry (almost like a > mechanical part) that you shape with 3D offsets based on the exact 3D > geometry. Specifically I am talking about modeling an alignment that has a > parabolic curve. > > DAS >
*scott mceachron
Message 27 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 11:49 AM in reply to: *Brian Hailey
Wouldn't it be sweet if Civil3D kicked it up a notch and allowed for the creation of a "curb-and-gutter" object, and when sampling sections along a centerline, the sampling routine knew to sample pc, pts, highs, lows, driveway intersections, et al from the curb-and-gutter object! sm -- scott mceachron total cad systems - dfw "Steve Cannon" wrote in message news:4052033e$1_1@newsprd01... > Dave, > > I guess my condensed version from the previous post is that the sampling > increment depends on what the resultant object is to be used for. If it, or > the resultant surface is going to be used for TC labeling, the vertical > curve sampling needs to be much shorter (tighter) than the sampling > increment along a horizontal curve. This is because we need TC elevations > to within 0.01'. But we do not need the whole alignment sampled at that > increment - horizontal curve sampling should be independent of vertical > curve sampling. If the resultant object is just intended for earthwork, then > we can get by with a much longer (looser) sampling increment through the > vertical curve (vertical +/- 0.1'). > > sc > > "Dave Simeone" wrote in message > news:4051e90b$1_2@newsprd01... > > > > Hi Steve - I guess the real question relates to working with 3D > arcs/splines > > (including parabolic vertical curves). What I was referring to in the > > tessellation is as follows: > > > > LDT/Civil Design grading - create a curve that you want to grade in Civil > > Design. When you grade this object the program has a setting that defines > > the increment that grading projections will be created along the arc. A > > small increment is more accurate, but higher in overhead. > > > > I would imagine that you want to keep the 3D geometry (almost like a > > mechanical part) that you shape with 3D offsets based on the exact 3D > > geometry. Specifically I am talking about modeling an alignment that has a > > parabolic curve. > > > > DAS > > > >
*Don Reichle
Message 28 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 12:24 PM in reply to: *Brian Hailey
Gee, Doug, cut the programming folks some slack. If it were as easy as you make out, don't you think it would have been done already? I'm glad for the steps in the right direction that they are taking at the moment, and by that I mean that they are listening to our input, not the quality or qauntity of the tools they are producing. -- Don Reichle "King of Work-Arounds" Ifland Engineers, Inc. "Doug Boys" wrote in message news:4051c5aa_2@newsprd01... > I think we should be able to have an interactive string element which has > its horizontal geometry defined with horizontal tangents and arcs and its > vertical geometry defined by tangents and vertical curves that designers are > familiar with but which displays the resulting 3D polyline as a feature or > property of that object the same way that the surface objects display > contours as a property. > > And the horizontal IPs and vertical IPs should be "displayable" also and > allow the designer to move them interactively. > > I thought that's what Civil 3D was going to give us. It would be called an > "Alignment Object" ? Where is it ? Haven't we waited long enough ? Come on > Dave, what's going on ? > > Laurie makes a valid point that at present the designers don't quite know > how to judge the correctness of the resulting grading but I think they will > quickly get used to that. It seems that intersection designers are already > designing by what "looks right" much of the time now particularly in hilly > country. > > Doug Boys > >
*Don Reichle
Message 29 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 12:36 PM in reply to: *Brian Hailey
OK, Steve... Inquiring minds want to know. What is your reasoning behind such tight tolerances for sampling in Horz/Vert? Unless you are doing a significant amount of runways in America, I can't imagine why you need such tight control. When the curb contractor sets up his string line for the curb machine to follow, unless they're going around a curb return the tightest spacing I've ever seen is 25 feet. -- Don Reichle "King of Work-Arounds" Ifland Engineers, Inc. "Steve Cannon" wrote in message news:4052033e$1_1@newsprd01... > Dave, > > I guess my condensed version from the previous post is that the sampling > increment depends on what the resultant object is to be used for. If it, or > the resultant surface is going to be used for TC labeling, the vertical > curve sampling needs to be much shorter (tighter) than the sampling > increment along a horizontal curve. This is because we need TC elevations > to within 0.01'. But we do not need the whole alignment sampled at that > increment - horizontal curve sampling should be independent of vertical > curve sampling. If the resultant object is just intended for earthwork, then > we can get by with a much longer (looser) sampling increment through the > vertical curve (vertical +/- 0.1'). > > sc > > "Dave Simeone" wrote in message > news:4051e90b$1_2@newsprd01... > > > > Hi Steve - I guess the real question relates to working with 3D > arcs/splines > > (including parabolic vertical curves). What I was referring to in the > > tessellation is as follows: > > > > LDT/Civil Design grading - create a curve that you want to grade in Civil > > Design. When you grade this object the program has a setting that defines > > the increment that grading projections will be created along the arc. A > > small increment is more accurate, but higher in overhead. > > > > I would imagine that you want to keep the 3D geometry (almost like a > > mechanical part) that you shape with 3D offsets based on the exact 3D > > geometry. Specifically I am talking about modeling an alignment that has a > > parabolic curve. > > > > DAS > > > >
*Laurie Comerford
Message 30 of 47 (94 Views)

Re: Civil3D 2005

03-12-2004 12:36 PM in reply to: *Brian Hailey
Hi Dave, In terms of graphic presentation, if a "chord" approach is used then probably all that is needed is a "chord offset" parameter, both vertically and horizontally. For plotting purposes this value can probably be quite large as at the usual plot scales it will appear smooth to the eye. Say I plot with a line width of 0.18mm at a scale of 1:500. This would translate to 500*0.18= 90mm, say 100mm or 4" However for design purposes it should be far more accurate. I would want to snap to this object and have full double precision accuracy. We certainly don't want to have issues with offsetting it when at large coordinates such as happens with polylines. -- Laurie Comerford CADApps www.cadapps.com.au "Dave Simeone" wrote in message news:4051e90b$1_2@newsprd01... > > Hi Steve - I guess the real question relates to working with 3D arcs/splines > (including parabolic vertical curves). What I was referring to in the > tessellation is as follows: > > LDT/Civil Design grading - create a curve that you want to grade in Civil > Design. When you grade this object the program has a setting that defines > the increment that grading projections will be created along the arc. A > small increment is more accurate, but higher in overhead. > > I would imagine that you want to keep the 3D geometry (almost like a > mechanical part) that you shape with 3D offsets based on the exact 3D > geometry. Specifically I am talking about modeling an alignment that has a > parabolic curve. > > DAS > > "Steve Cannon" wrote in message > news:4051e260$1_1@newsprd01... > > Dave, I had to re-read your post several times to try and understand > exactly > > what you are asking: > > > > >Historically we've generally "accepted" the tessalation (tessellation?) > > >of 3D vertical curves ... when working from a grading feature line. > > > > Laurie seem to assume you were talking about the parabola in a profile > > view - and if this is the case, I am comfortable with the status quo > > graphical representation. However, it sounds to me you are talking about > > the sampling increment of 'Z' data to be placed in a potential grading > > feature line. Historically, I did know that either LDT or C3D had any > > routines that did this. The LDT 'Superimpose' profiles is the only > existing > > AutoDesk routine that I know that samples a profile at an increment. If > > this is in indeed what you are asking - it scares me to think about the > > direction you might be heading! > > > > Background: Within LDT, we have written our own 3Dpoly to Profile and > > Profile to 3Dpoly routines. In going from Profile to poly we sample at > all > > critical points: PI's, PC's and PT's in the XY alignment. We sample all > > PVI's locations from the profile. The routine requires a horizontal curve > > sampling factor and a vertical curve sampling factor that are > independent - > > because of the nature of the mathematics. We make it user selectable - but > > more often than not we will use a 0.5' foot horizontal sample through a > > vertical curve and a mid-ordinate distance sampling criteria for > horizontal > > curves of 0.05'. This can result in a large number of 3dpolyline > vertices. > > The resultant 'tessellation' seems to be pretty good for terrain surface > > creation, but here are the other design problems we encounter with this > > approach: > > > > - The large number of closely spaced vertices can make grip editing and > > critical point location tough to id in plan view. > > > > - A 3d object looses 2d characteristics - for example you can no longer > > query horizontal curve from the object. > > > > - Plan lengths are replaced with True lengths on the object. Stationing > is > > lost. Neither AutoCAD nor LDT provide easy to use tools for plan queries > of > > 3d AutoCAD objects. > > > > - The large number of vertices make it difficult to locate true slope > > breaks. > > > > - For all the above reasons the designer needs keep two layers of > segregated > > design data - one for plan work and one for 3d design work. > > > > It would be my hope that C3D did not go down the same path. As I sit here > > and type, I see that Doug just now expressed my very concern in his reply > to > > Laurie above: > > > > > I think we should be able to have an interactive string element which > has > > > its horizontal geometry defined with horizontal tangents and arcs and > its > > > vertical geometry defined by tangents and vertical curves that designers > > are > > > familiar with but which displays the resulting 3D polyline as a feature > or > > > property of that object ... > > > > This 'string' element could potentially be an alignment. It 'handles' > > horizontal manipulation. The present C3D problem I see is that the > profile > > is not a property of the alignment, but instead an independent object. If > > the profile was a property of an alignment, whereby the user could > > right-click on an alignment and manipulate the 3d elements of the > alignment > > by both graphical (profile) and tabular (sta-elev-pvi) means, we have the > > starting structure for the string object. If I queried a location in plan > > view along the alignment, I should also be able to get the vertical (z) > spot > > data. If I 'snapped' to any location along the alignment I would also > snap > > to the z coordinate, which is retrieved from the profile property. If you > > gave me plan tools, whereby I could change the elevation of a spot > location > > on the alignment, that elevation would reflect in the profile property. > If > > you gave me a tool to interpolate a slope between two horizontal vertices > on > > the alignment, it would reflect in the profile property. There should be > no > > reason I couldn't add a vertical curve in plan view. I could see a full > > range of interactive site design tools that allow you to modify a point in > > plan view based upon slope, grade, or vertical distance from other > 3dobjects > > in the drawing. You could even have a routine similar to the LDT 'Curb' > > routine: pick the alignment, an offset distance (horiz) and offset > distance > > (vert) that created a new OFFSET Alignment (say L1) and OFFSET profile > that > > was based on the main CL stationing. OFFSET alignments also have their > own > > associated profile property that could be manipulated after the offset. > For > > that matter, the horizontal alignment could also be post manipulated with > > grips or whatever, while interpolating new 3d(profiles) by stretching or > > extrapolating. > > > > And of course, they key to real productivity is that the alignment can be > > used as a feature line for grading objects. As such, the > alignment-feature > > line keeps its plan and profile features, and any tessellation required > for > > tin creation is kept in the background and not even seen by the designer. > > Horizontal curves still appear as smooth arcs. Grips remain on the > alignment > > only at critical stations. The programmers should be able to come up with > > internal algorithms for sampling such as mid-ordinate for horizontal > curves, > > and a similar property for vertical parabolas based upon algebraic > > difference in slope and length of vertical curve. Never bother the > designer > > with having to make tessellation sampling decisions - it should all be > > transparent to him. > > > > sc > > ----- Original Message ----- > > From: Dave Simeone > > Newsgroups: autodesk.civil3d > > Sent: Thursday, March 11, 2004 5:09 PM > > Subject: Re: Civil3D 2005 > > > > > > Excellent feedback. > > > > Q - Historically we've generally "accepted" the tessalation of 3D > vertical > > curves (ie, break the geometry into short segments) when working from a > > grading feature line. I'm guessing that ya'll - (I'm trying to learn to > > speak in Wedding's language - I've got "Ya'll" and "All y'all" down > pretty > > nicely) - would like a smooth 3D spline. What is the requirement? The > > smoother the better? Engineers go to great lengths to have accurate > > vertical > > (profile) geometry. I'm guessing that the true 3D geometry should be > > carried > > through the grading of the EOP, Kerb (how's that all y'all Aussies?), > etc > > geometry. > > > > Thanks > > DAS > > > > > >

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