Remove an area of grid points

PIX4Dsurvey
1

In some situations trying to use grid to create a surface there are areas, or regions, of grid points that need to be removed or classified as non-terrain.

What we have found is if we use the polygon to outline the grid points and then delete them it also deletes the point cloud below them even if the point cloud is set to no display.

Is there a way to remove or re-classify an area of grid points while leaving some sort of image on underneath so that I could tell where that area is?

If I could lock the point cloud that would work.

But if I need to use just poly lines to create the surface correctly, like a bridge deck for instance, I do not see an easy way to not use the grid points, or to do it at all without also removing an area of point cloud

2

Hi photchkiss,

The grid of points is a function of the classification of the point cloud. Therefore, it appears that you need to accurately classify the point cloud in these areas. The automatic terrain filter works pretty good but there are usually areas that need manual classification. Have you tried to manually classify these areas?

3

Not there. But to be sure I understand, the grid will only be created where the point cloud is classified as terrain? So the fix is to mark an area as non-terrain first then create the grid. If done in that order, the grid will not be created where the point cloud is something other than terrain.

Makes sense. But a direst answer is I cannot delete a block of grid without also deleting the point cloud in that area. I cannot “lock” the point cloud.

4

Have you tried using the Color-based selection tool? This can be useful for selecting terrain versus non-terrain in the point cloud.