adjust real world size (meters?)

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11-29-2022 12:38 PM
Unity_gis
New Contributor III

Can the map real world size/measurement value be adjusted?

I'm using some models from cloud compare and the sizes don't match. my models (of a neighborhood) are about 85% sized when layed over the arcGIS SDK for unity map.

I thought both environments where measured in meters, or is that wrong?

They aren't terribly large models so it doesn't seem to be ellipsoid vs flat Cartesian coordinate type of a conversion issue. The streets are visible smaller when layed over the arcgis map in unity

 

 

 

 

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6 Replies
Matt_Nelson
Esri Contributor

Hard to say for sure what is going on without being able to see how you are authoring it but can you not just scale your models?

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Unity_gis
New Contributor III

Yes, I can scale the objects and that is what im doing for now, but wondering if there was another way.

Here is what I have: 
2 different professional lidar scanners. Both output .las point clouds.

I bring large area scans in to cloud compare application. I note the points, shifts, bounds etc.
and
I bring them in to unity with a 3rd party library.

I compare in unity and in cloud compare that everything does indeed measure the same based on units
See photo in cloud compare.

In unity I measure with a sized cube. The units/point measurements are identical.

So all is well.

But, when I lay these scans over the unity ArcGIS maps, the scans are smaller by about 20%

So yes, If I scale the clouds (about 1.19% approximately) then everything lays over the maps alright.
(You can scale these point clouds in cloud compare or unity)

But it seems a little weird, and you have to fiddle with it to make sure its ever so perfect and maybe that scale wont work for all files, not sure.

So 2 different lidar scanners, 1000 unity points = 1000 cloud compare points = .las files automatically fit maps in QGIS application as well. Everything seems to be in harmony with each other.


1 cube in unity is supposed to be 1 meter in real world (although that's all relative i suppose)

But when fit to the ArcGIS SDK the size is off by a weird size (1.19% or whatever).

So, if the ArcGIS SDK for unity is one size and that is that. Then I will use that as the master size and scale everything accordingly...but I don't like it. Now these point clouds are altered and wont work in other GIS applications as is.

...so what im trying to say is i don't know if/how there is some standard but everything everywhere seems to fir the point clouds accordingly except the ArcGIS sdk in unity size does not fit without point cloud modification

 

cc.jpg

 

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Matt_Nelson
Esri Contributor

Can you test these in a local and global map just to rule that out for me?

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Unity_gis
New Contributor III

Sorry didn't see your reply before my other one. Yes I will test that tomorrow and get back to u. I was testing in a local only, and to clarify I am using a plugin to import the .las to unity but looking at the coordinates it seems unit for unit the same as cloud compare unless i'm missing something.

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Unity_gis
New Contributor III

O. M. G it works in global! 😀

I thought I tried that but I guess not. In global, I import the point clouds, set its corner point with a location component and it overlays correct. 

In local mode, I would need to scale the point cloud up approx 1.2% 

unless there is a setting to change that i might call that a bug? I was using local because I read somewhere in the docs that it was preferred for fine tune/measuring. 

what I will be doing is basically laying large area point clouds over the map and need as much accuracy as i can

thanks man that was a life saver

 

 

 

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Unity_gis
New Contributor III

Also, I place them on the map with the stored GPS coordinate which is one point in the corner. from there scaling out 1.19234234% or whatever, I can visually look at it and say ok it looks to visually fit over the base map, but you can imagine how this gets problematic or scary for large miles long scans just kind seems like its not a reliable fit, but I will test with other files, hey if they all scale the same and fit exactly i guess thats ok but seems like im setting myself up for disaster

 

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