Geolocation marker and Point for the location

[Haider_of_Sweden]

I am trying to understand what this Geolocation Marker Point does.

Its so tricky for me right now, that I am not even sure I am phrasing the question right.

If I setup the scene with MAPCSASSIGN, assign the right coordinate system and turn on the map, I can see that the position (X,Y) correlates where things should be. Lets say something around X,Y 155000,6570000.

But then there is this GEOREORIENTMARKER command (or if I run GEOGRAPHICLOCATION > MAP) that lets me pick a position in my workspace, eg 0,0 even though that position on the map should be something like 155000,6570000.

What does it mean?

Does it mean I am "operating at 155000,6570000" geolocation-wise but in Civil, I am drawing around 0,0 cad-wise?  

[samir.rezk]

Hi @Haider_of_Sweden 

The GEOGRAOHICLOCATION command is “vanilla” AutoCAD way of projecting the X,Y drawing canvas onto a certain location in our planet, it does this by setting a certain point (the GEOLOCATION Marker) in the drawing to a LAT, LONG (WGS 84 / GIS Coordinates) on planet earth, this is done manually, so you need to know the point and it’s world coordinates before hand.

In Civil 3D and AutoCAD MAP 3D, we can set the Coordinate System directly to the drawing. The installed coordinate system files contains the point correlation information to project the drawing canvas to known coordinates for state/country/UTM systems; this makes it a lot easier because we don’t have to know the correlation information or manually set it like in the case of plain AutoCAD.
This is my long explanation of saying do not use AutoCAD GEOLOCATION Commands within Civil 3D. Assign the Civil 3D Coordinate System from the Drawing Setting dialog only, and your drawing will be geolocated appropriately, automatically, and more accurately by using local coordinate systems.

Hope this helps,

[Haider_of_Sweden]

As a side note, thanks @samir.rezk for pointing out that the GEOGRAPHICLOCATION command did exist in AutoCAD. I didn't know that. Even if this wasn't my original question, the benefit from knowing this is that you can define a coordinate system in vanilla AutoCAD and I thought this could only be done in Map3D or Civil3D.

Back to the topic though.

In Civil3D, when you go MAPCSASSIGN, and for example assign 3011 (SWEREF), and then afterwards type in GEOGRAPHICLOCATION, I get 59.675,18.341667. That's where the marker is.

If I understood you correctly, you mean the marker location is stored in the installed coordinate system files, as you call it?

If so, what is this location anyway? It is located at 169251.627,6617914.273, but why there?

Can you please try to explain to me, the purpose of the Geolocation marker?

Let me further explain what I hope to learn.

As stated, the point was located at 169251.627,6617914.273 (meters). I would like to define the CS to SWEREF but still be closer to the location 0,0. Is that what the Geolocation marker is for?

Furthermore, I intend to take this DWG and load it into Infraworks, which require georeferenced files. Instead of moving my stuff from 0,0 to eg 155000,6570000, I would want to keep it to 0,0 and make Infraworks still understand that my model is actually located on 155000,6570000.

So does the Geolocation has anything to do with what I hope to achieve?

[Pointdump]

Hi Haider,
"So does the Geolocation has anything to do with what I hope to achieve?"
Quick answer: No. Don't use any of the Geolocation Commands in Civil 3D or Map 3D. Use Drawing Settings or MAPCSASSIGN. If you need to find a place, use Zoom >> Center.
"I would like to define the CS to SWEREF but still be closer to the location 0,0."
You can draw in SWEREF Coordinates or you can draw at 0,0 but not both at the same time. Xref your (0,0) floor plan into your SWEREF drawing and then you can load into InfraWorks.
Dave

[samir.rezk]

Hi @Haider_of_Sweden 

If you need to work near 0,0 but continue to have the drawing geolocated you will have to create a custom coordinate system with and from the MAPCSASSIGN Command (see Link for more info). The Geolocation marker location is always relative to WGS 94 lat,long coordinates only, the marker appears in the centroid of of the CS Extents, but it is not indicative of anything relating to Civil 3D. It is purely an AutoCAD feature not sufficient enough for Civil design.

Perhaps the real question is why you want to draw close to 0,0? Usually with Civil engineering, we want to be in the true project location and based on established coordinate systems is always much preferable!

Hope this helps,

[samir.rezk]

Hi again,

Also worth to note, InfraWorks does not support custom coordinate systems at this time! If you expect to add Civil 3D data as a data source in InfraWorks, then the Civil 3D drawing must have a Coordinate System assigned from the standard list.

[Haider_of_Sweden]

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@samir.rezk wrote:

If you need to work near 0,0 but continue to have the drawing geolocated you will have to create a custom coordinate system with and from the MAPCSASSIGN Command (see Link for more info). The Geolocation marker location is always relative to WGS 94 lat,long coordinates only, the marker appears in the centroid of of the CS Extents, but it is not indicative of anything relating to Civil 3D. It is purely an AutoCAD feature not sufficient enough for Civil design.

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I think this answers the question I am asking - let me please just make sure it does. No matter the CS, the marker always ends up in the center of the coordinate system, is that right?

Plus, you can change its location.

Any suggestion why this feature exists even?

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Perhaps the real question is why you want to draw close to 0,0? Usually with Civil engineering, we want to be in the true project location and based on established coordinate systems is always much preferable!

Hope this helps,

---

True 🙂

Let me tell you why. I do know of MAPCSASSIGN and I always work in the right XY location of where things are.

However, sometimes my source data are made in software that do not support real coordinate systems. For example, a project done in SWEREF (Sweden) could be located at 156850,6568917 meters. Revit or 3dsMax cant work this far from origo.

So, I do my stuff close to 0,0, export them to DWG.

After doing lots of tests, I discovered

- Infraworks does mostly (there are some cases that I still haven't solved) support offsets

- Infraworks supports non-geolocated files, and lets me define the CS inside Infraworks instead

So the whole thing about me asking about this strange Geolocation marker is because I was wondering/hoping that I could work at 0,0 but pretending being at 156850,6568917.

ps. you know Infraworks as well?