export with a transformation

Development Asset Creation
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1

Hello.

I made a project with RC in a grid coordinate system.

When I export the point cloud as a.las I see an option to make (if I want) a translation in the grid coordinates.

This is perfect because normally I want to work in a local system.

To translate data from a grid projected system to a local ground system I must apply a combined scale factor in the x and y axes and leave as it the z-axis.

I see that I have the option to apply different scales to the x, y, and z-axis.

What I don’t understand is which is the origin from which these scale factors applied.

Because the output coordinates depend on the origin where the scale factor applies.

 

thank you

 

2

Hi Nikoue,

are you sure with CC or is it just a typo?

Origin of coordinate system is showed by grid in RC. It is where two black axis are met and scale is computed from this point.

3

It’s a typo and I corrected it. I have in mind cloud compare where I usually made these transformations and that’s why I wrote CC.

If I simultaneously make a translation in x,y,z, and also apply scales what’s the order of the computations?

I have defined a local site in the area and I want to match the point cloud with other cad elements.

How can I find the coordinates for the center of the grid in the projected coordinate system used in a project?

Thank you.

4

When you make translation and scale the model, the model is scaled and then moved with wanted translation.

The center of the grid has 0,0 coordinates in local system. If you are using some global system, then it is transformed to this system. In this case it will be good to have some control point with coordinates and use these points to align the model to this coordinate system. 

Theoretically you can find out these coordinates, when you create a reconstruction region over grid (Set Region on Grid) in the place of the center and export this reconstruction region. Then when you open this rcbox file in Notepad, there are the center coordinates.

  

5

Hello and thank you for your answer.

I understand what do you mean but when I tried to create a region over the grid I am not able to snap on the grid, as I saw in your image.

What I am doing wrong?

6

You have to first clear the reconstruction region. Then choose Set Region on Grid and select the borders of the region by left click.

7

that’s exactly what i am doing but it doesn’t snap to the grid

 

8

My also isn’t snapped. It is just approximative. I just zoomed it to maximal possible distance and click.

For example zero coordinates for local system:

-6.19888305664063e-006 -4.23192977905273e-006 -0.00061331782490015 (which are almost zeros) 

9

ok, thank you very much for your answers.

Perhaps you can improve this feature. I think that’s something easy. Give full control in translation and scale operations.