For the last couple of weeks, I have been doing a research for making a detailed footprint with LiDAR data. The detailed footprint is needed for visualizing a 3D model. With a detailed footprint I mean a footprint with information of the rooftops within blocks of buildings. This information are different levels/heights, walls, holes etc. Some questions arose during this research. The process consists of two steps: 1. Classifying the LiDAR data and 2. Creating a detailed footprint. The first step is done. The last step, creating the detailed footprint, cause me a lot of problems. For this step I tried a lot of different tools and workflows but none of them gives me the result I want.

The Classified LiDAR data for the footprint consists of blocks with flat roofs and different heights/levels:

LiDAR Building classification

The most tools for creating a building footprint are only creating the outline of a block/house. A good workflow for the solution of my example is LAS Point Statistics as Raster, Raster to Polygon followed by Regularize Building Footprint. But, there is always a problem with the first step. When I run this tool, I’ve got the next result:

Raster output

In the Image above you can see a raster of the rooftops from a block of buildings. I want that raster to be visualized as a footprint (polygon). The footprint contains information of the rooftops with different heights/levels and components(walls, for example) in a block. In the image above is the output raster faced North. This is wrong, because the footprint needs to be straight. This is not the case in the image above. The edges and information within the blocks are ribbed.

In this case, the raster output needs to be rotated by 37 degrees. When it is rotated like this, the blocks and information within the blocks are straight. The raster output should look like this:

Rotated raster output

So, the end result is a detailed footprint/polygon of the rooftops based on elevation. With detailed I mean all the levels of the blocks are different polygons within the polygon of the block, like this:

Result example

This can be done with a raster. How can I rotate the output of the raster to get a straight raster that matches with the blocks

Or, is there another way to create polygons based on heights. For example, in a block are five buildings with different levels/heights. How can I visualize these different levels/heights in different polygons?

Or, has somebody another suggestion to visualize a footprint the way I want?

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    This is confusing. What is the question? I ask because you give a lot of context, but the final question suggest your post could be simplified for better understanding. For example: Is there a way to set the right rotation for the output raster? What is the right rotation? Why facing North is not correct? How do you want to visualize the footprints? Also, what do you call as 'footprints': i) the point cloud filtered by points which represent rooftops; ii) the polygons representing rooftops; or iii) the raster representing rooftop's elevation? In other words, what are you trying to visualize? – Andre Silva Mar 2 '18 at 15:51
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    Reproject the raster into a custom "Local" projection? Set the lat/lon of center to the center of your data and azimuth to the amount of rotation from north that you want. – mkennedy Mar 2 '18 at 18:15
  • @AndreSilva Thank you for responding, I edited my question based on your feedback. But, I will explain it briefly, I want to visualize a footprint with information of the rooftops within a block of buildings. The blocks of buildings consists of different heights/levels witch I want to visualize in the footprint (polygon). – Bas W. Mar 5 '18 at 10:31
  • @mkennedy Thank you for responding, can you give me some more information of how I can create a custom projection? The Coordinate System I am using for this project is ED 1950 UTM Zone 33N and Transformation ED 1950 To WGS 1984 12. The output rotation needs to be 37 degrees. – Bas W. Mar 5 '18 at 11:27
  • "In the image above is the output raster faced North." In the two images both rasters are faced north (look the tiny pixels of each one). What changed was the grid over them (in first picture, a grey grid, in the second a red grid). What are those grids? "This is wrong, because the footprint needs to be straight." Considering the footprint is the final polygon, why does it need to be straight (I assume 'straight' is North oriented?). Doesn't it need to only wrap the correct amount of pixels with same elevation? – Andre Silva Sep 28 '18 at 17:38