title: Create GeoTIFF from LIDAR file
body: <p>Generally I'm trying create raster from LIDAR cloud (files with extension .las) to geoTif. It is new to me and I don't know how I should start. For now I read all points from las file and I check all point by dimention 'Z' and each highest point draw in tif file. For create tif i use GDAL library from QGIS. </p>
  
  <p>In LASTool and I found app which convert LAS to TIF but it is paid. I need something what is free. Maybe somebody had the same problem and he will share solution?</p>
  
  <p>Moreover I need to my tiff file had tiles. So if somebody also had some code I will be grateful. </p>
  
  <p>EDIT:</p>
  
  <p>Thanks @chambbj , generally it is good suggestion because PDAL is great but this solution create me tif in grays colors. but I need something what will consider all colors in LAS file. I saw filters (colorization) but it not work :( maybe i'm doing some wrong? I don't know. 
  Would be great, if I able to separet all point in cloud by max Z dimension and create tif file.</p>
  
  <p>Example:
  For now I have something like this
  <a href="https://i.stack.imgur.com/z7byK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/z7byK.png" alt="enter image description here"></a></p>
  
  <p>but I need some like this:
  <a href="https://i.stack.imgur.com/AFcXO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AFcXO.png" alt="enter image description here"></a></p>
  
  <p>Each pixel is 5cm2</p>