I am trying to create a 3D masterplan in Sketchup using a site’s actual terrain. I was able to import a fairly detailed LIDAR survey into Sketchup by importing a .DEM file
The result is very detailed and reveals the subtle features of the land, but created a very complex model (left below)
In a separate file, I also imported the same terrain via the “Add location” feature. The result is much smoother/simpler but lacks a lot of the detail that the LIDAR data provides (right below)
I’d like to ultimately create something similar to what user eric-s shows in this thread:
My question:
Is there a way to smooth and simplify the Lidar data so it is more like the second example but I keeps the most of the detail but is a manageable base map for a newish Sketchup user like myself? Or do I need to settle with the lower fidelity imported terrain.
Note: I have played around with the built-in Smooth/Soften functions but they didn’t really do much to help as far as I could tell.
hi @ahbrown37 - your question about what is ‘manageable’ is a bit relative. How big is your file both in terms of SketchUp file size and number of edges/faces? I’ve found that simply turning edges off and saving a new Style is usually enough to keep things moving efficiently on big terrain models such as this. That’s why when you import terrain from Geo-Location it automatically ‘hides’ the edges.
You can ‘smooth’ the model in several ways. Firstly, like I said above, you can simply create a style that has edges off but if you need edges to show on other parts of the model then that may not work. You could also use the ‘Soften Edges’ window and with your mesh selected, click ‘Soften Coplanar’. Or lastly, you can use an extension like ‘Hide All Edges’ which is a fast way to hide edges of only certain groups/components (and then bring back later if needed as well!).
Also, in addition to the extensions @mihai.suggested, you could look at either Skimp or Transmutr that allow you to reduce the polygon count of any object. You have to be careful here as there is a balance between accuracy (high poly) and performance (lower poly) so you’ll want to find a balance that works best for your needs/computer setup.
Right now the model (which is just the terrain) is 18MB and 120k edges and 80k faces
I guess when I say “manageable”, I want to add structures, vegetation, etc to this base model and I don’t want the underlying model to be so complicated that that is prohibitively difficult. I think the strategies you suggested to reduce the polygon count will help w that.
When I say “smooth”, what I would like to do it get rid of the “ledges” which don’t exist in reality and I think are just an artifact of the lidar data.
Thanks for your helpful response and apologies for the imprecise language.
The problem is much topographic data has too many points and you want something that is close but not ridiculously detailed (i.e. fake ) or a mass of random triangles. So I think the way Toposhaper and other plugins like Instant Terrain create an even mesh that is a representative of the terrain as needed. I like to clean up the topographic information beforehand, using CAD simplification techniques removing sharp angles and contours that are too close together. TopoShaper also has cleanup routines. But what I go for is a even rectilinear grid like Toposhaper that I can manipulate, cut, and augment.
