topic Re: Create Surface from Points in AutoCAD Map 3D Forum

Create Surface from Points

john_daues — Thu, 07 Jan 2021 19:15:17 GMT

Following instructions here:

https://knowledge.autodesk.com/support/autocad-map-3d/learn-explore/caas/CloudHelp/cloudhelp/2020/ENU/MAP3D-Use/files/GUID-A44A4C38-3C98-4DB3-8387-1CD6D941FFF1-htm.html

I enter the command MAPCREATEPCSURFACE, then I do ctrl-A to select all the points then Enter.

At this point, its says that "The Create Surface from Point Cloud dialog box appears", but it does not.

What am I doing wrong?

Re: Create Surface from Points

rkmcswain — Thu, 07 Jan 2021 19:17:32 GMT

Because your command line is so tiny, I can't see any history there. So when you selected the objects, did it actually select them? Or were you objects filtered out?

Re: Create Surface from Points

john_daues — Thu, 07 Jan 2021 19:28:41 GMT

I thought that the blue in the screenshot indicates that they are selected but now I'm not so sure.

It may be that ctrl-A cancels the command. And if I try to select the points with the mouse, either by corralling them or individually, they don't get selected.

Also attached the command line window to this message.

Re: Create Surface from Points

rkmcswain — Thu, 07 Jan 2021 19:34:55 GMT

Just because something is selected doesn't necessarily mean that the command is accepting those objects as input. As a start, don't use Ctrl+A, enter "ALL" as your input for the selection.

Next if further support is needed, please create a screencast and expand your command line to 4 or 5 docked lines during the recording of the screencast, so we can all see exactly what is happening.

Re: Create Surface from Points

john_daues — Thu, 07 Jan 2021 19:56:28 GMT

When I do ALL it says "0 found", so these points are not valid input for the MAPCREATEPCSURFACE command.

The page I referred is instructions for "Point Cloud Data". Is a set of points not point cloud data?

Re: Create Surface from Points

rkmcswain — Thu, 07 Jan 2021 20:01:11 GMT

Correct @john_daues - try the command MAPCREATESURFACE instead

Re: Create Surface from Points

ChicagoLooper — Thu, 07 Jan 2021 20:58:28 GMT

Civil 3D. Steps to create surface.

Toolspace=>Right click Surfaces=>Create Surface=>Give your surface a Name and a surface Style=>OK
In Toolspace go to your new surface=>Expand surface Definition=>Right click Drawing Objects=>Add=>Points=>OK. Select your points using a crossing window.
Surface is created. Optional: click your surface=>right click=>Object View=>left click+drag to rotate and view.

Warning:

Step 1 should be assign an appropriate coordinate system to Modelspace and remaining steps should be 2, 3, and 4.

STATS (Using your PNEZ point file):

The following assumes feet. Is your point file in feet or meters? No info given so assumptions must be made.

Total Points 200

Highest point 7,587.74 ft

Lowest point 7,579.52 ft

Elevation range: 8.22 ft

Coverage Area: 404,717.86 square feet (9.29 acres) or the approximate size of four Home Depot Stores

Considering both the area and elevation, your site, being so big with very little change in elevation, will appear as flat.

Surface created from points:

Contours at 1/2-ft intervals.

Area is 9+ acres. Difference between highest and lowest points = 8.22 ft.

You have some problems and you should address them sooner than later. Your best bet, ask the point creator or point collector for the missing info.

Your points are not georeferenced. (A georeferenced object means its relative position, when compared to the equator and North Pole, is accurate.) If you bring other entities such as georefenced roads, buildings, underground infrastructure, aerial photos, etc., etc. they may not appear in the vicinity of your new surface. Your current surface might even appear out in space, in the middle of the ocean. What is the projection (CoordSys) for Point.csv?
The elevation or z-value of your points, e.g. 7500 feet is habitable but not too common. Denver, affectionately known as the Mile High City, has an elevation of 5280 feet. Can you verify the elevation values? Is Point.csv in feet, meters or something else?

Re: Create Surface from Points

rkmcswain — Thu, 07 Jan 2021 21:35:17 GMT

@ChicagoLooper wrote:

Civil 3D.

According to @john_daues (in this post) - he/she is using AutoCAD MAP, not Civil 3D.

Re: Create Surface from Points

ChicagoLooper — Thu, 07 Jan 2021 23:22:02 GMT

@rkmcswain wrote:

According to @john_daues (in this post) - he/she is using AutoCAD MAP, not Civil 3D.

Mr. McSwain,

Yes, I know. So what does that say about using M3D? What does it say about using C3D or about using Vanilla AutoCad to create a TINN surface? The implication is you need the ‘right tool’ for the ‘right job.’

What would be helpful is full disclosure by the OP. A thorough, detailed explanation may, or may not, suggest an alternate workflow that doesn’t rely on a TINN and only requires Map3D’s toolset.

In the absence of full disclosure and the given the PNEZ data, the Civil3D toolset was presented to demonstrate the most common AutoCad workflow used in the design/engineering industry.

The C3D toolset also lends itself to additional Civil3D workflows such as surface profiles, proposed grading, and volume calculations. Whether the OP has or doesn’t have the toolset is didn’t play a role when offering it as a suggestion.

Re: Create Surface from Points

john_daues — Mon, 11 Jan 2021 17:38:20 GMT

As pointed out, I'm using MAP 3D, not Civil, so the instructions above are not applicable.

You ask for full disclosure. What do you want do know?

Re: Create Surface from Points

braudpat — Mon, 11 Jan 2021 18:18:05 GMT

Hello

If you have 3D Points XYZ into your DWG, you can use the beautiful "Triangulate" routine from Elpanov !?

The "Triangulate" routine runs on any ACAD, ACAD MAP, ACAD Architecture, etc, and draws a DTM made of 3DFaces from many 3D XYZ Points ...

http://elpanov.com/index.php?id=6

Please use the APPLOAD command to load the routine ...

THE HEALTH, Regards, Patrice

Re: Create Surface from Points

ChicagoLooper — Mon, 11 Jan 2021 18:25:00 GMT

There's no good way, if any, to create a 'surface' using AutoCad Map 3D. The only AutoCAD workflow is to use Civil 3D. Please disclose in as much detail possible, what you are trying to achieve, e.g. I want to draw topographic contours, I want to analyze slope, I want to calculate volume, etc. It could be a surface is not necessary at all or there might also be another workflow. An alternative workflow may, or may not, be just as good or might be a half-arse, way of doing it in Map 3D which would give you a work-a-round when C3D isn't available.

Without disclosure you're out of luck and you'll have to hand this project off to another colleague, or worse, lose it to another firm.

Re: Create Surface from Points

john_daues — Mon, 11 Jan 2021 18:28:25 GMT

This is topography. The plan is to create this surface, then another surface that has same x,y but different z (elevation) and then create a surface that is a difference of the two.

Re: Create Surface from Points

braudpat — Mon, 11 Jan 2021 18:46:31 GMT

Hello @john_daues

1) +1 with @ChicagoLooper ! ... ACAD CIVIL is the RIGHT Software !

2) BUT if you have ONLY ACAD, ACAD MAP, ACAD Architecture, etc, there is a workaround ...

3) Create the 2 DTMs with the Elpanov or (gile) routine ...

4) Transform the 2 DTMs as 2 3DSolids with the "right" routine ...

5) Then do a 3D SUBSTRACTION between the 2 3DSolids (the highest minus the lowest) and you will get your result ...

---- IF you are looking for the volume difference between the 2 DTMs !?

THE HEALTH, Regards, Patrice

Re: Create Surface from Points

ChicagoLooper — Mon, 11 Jan 2021 19:45:45 GMT

@john_daues wrote:

<<This is topography. The plan is to create this surface, then another surface that has same x,y but different z (elevation) and then create a surface that is a difference of the two.>>

That is what's called a volume calculation and it's traditionally performed in C3D, not Map3D.

If your second surface is higher that the first, then that is your FILL, as in creating a hill from flat land when designing a golf course. If your second surface is lower than the first then that is your CUT, like when designing a sand trap or a ditch. The fill or cut is exactly as you describe: the 'difference' between two surfaces.

<<Common examples of using the Civil3D toolset is highway design including on- and off-ramps, grading raw land to finished grade especially to facilitate drainage flow, detention pond excavation to accommodate a certain volume, designing a level building pad, determining foundation wall heights, etc., etc.>>

Cut and fill calculations are one of many built-in tools available in the Civil3D toolset. The C3D toolset is also capable of creating a transitional slope from the outer edges of your second (or proposed) surface so it meets, or blends into, your the existing surface. In the absence of a transitional type of surface, there's no 'connection' between the first and second so one of your surfaces will be floating in space. There are even various elevation editors which manipulate the elevations of vertices and individual points during your surface design which enables you to fine tune your finished grade. Do you believe you have the right tool for the right job?

While the makeup of Map3D provides you with strong analytical features, analytical tools that aren't available in C3D, it does not have C3D's surface design capability. To achieve your goal, you may use a lisp, however the lisp will likely be narrow in focus or specialized to do only one thing. It won't provide the design options or the if-I-do-this/then-this will-happen manipulation that's available in C3D.