Does anyone know how to create a land plot with accurate topography (based on the RLs) from a survey which only contains the RL points around a site. There is lots of examples and videos where people are using pro sketchup and plug ins (such as sandbox) to create a mesh and then smooth the points.
Hoping there is a more manual way of doing this using the free web version.
I was thinking of mapping the RLs using lines, where to from here?
It would be all manual in the web version.You can plot the boundaries based on the lengths and bearings given in your document. You might need to calculate some angles if they aren’t perfect 90° corners. You could also generate a screenshot image from your PDF and import that into SketchUp as an image. Then trace it to get the geometry. As for the topography you trace contour lines if you have them in an image you can import. Once you have the contours drawn you can use Push/Pull to create a sort of wedding cake like thing. Then stitch the vertices of the contours together with the Line tool to create the smooth surfaces.
How accurate does it have to be? I presume this is a hobby project since you are using the free version of SketchUp.
Yes hobby at this stage. My survey doesn’t have contour lines only RL point references. All the examples in videos online seem to take the wedding cake approach but not all surveys have topogrpahy available
To use the points, figure out the lowest one to use as your datum and subtract that value from the rest to get absolute heights above the ground plane. I would suggest recording them in a column spread sheet and let it do all the math for you. With the image imported into SketchUp you can place vertical edges at each point drawn to the absolute heights. Then connect those verticals by triangulation to get the surfaces. Of course the accuracy will be determined by the number of points you have.
You would need more points to create smaller triangles. Basically a higher resolution survey. I would guess that exists somewhere. Maybe the surveyor can supply that. Once you’ve got the surfaces created you can select it all, right click on it, and choose Soften/Smooth Edges to soften the edges of the triangles so they aren’t visible.
Note this kind of stuff can be easier in SketchUp 2024 because you can generate a point cloud that can be imported (several different ways to do that) and use extensions to generate the surface. Even so, the precision of the terrain won’t be any higher with so few survey points. You could import 3D terrain with the Add Location feature in SketchUp 2024 but how precise that terrain is depends a lot on the area. The terrain data won’t be obtained from the survey and it will average a lot of the terrain points out.
I just looked up the address in the PDF. It looks like there’s little terrain to survey because the houses are all cheek by jowl. Might not be worth trying to get a higher res survey. Or maybe you can go get the points that are important to you. I bet you could make some simple survey tools to do that. If you can get a clear view of enough satellites you could use a hand-held GPS to get more data points.
thanks Dave - yeah not much more than a coule of steps fall in the terrain, just hoping I might have been able to decipher more accurate way of rendering the land plot with limited data. I think I will simplify it and just try to map out the step changes with slight gradient and make some assumptions lol
Good luck with that. I was thinking it could be kind of fun to make a basic water level with a garden hose and go around with a tape measure and plot some points. More fun there than here. Here the water would freeze in the hose before I could plot the first point.
