Creating terrain modelling in SketchUp Make by hand

I am using Sketchup Make 2015 and want to try and create a terrain model from drawn contour lines.

I created the drawing in CorelDraw X7, so it is more accurate than the Google earth modelling (which I tried in sandbox but the results were not to my liking). There seems to be no ways to import a vector image into SUMake, so I am thinking that I should perhaps re-draw the contours with a digitiser pad and pen stylus.

I can import the CorelDraw image into Sketchup, but I am unsure of the process to create a terrain model this way. Do I create an individual layer for each contour - land rises from 40 metres to 300 in 20 metres increments, so 19 layers? In which case how do I go about hand tracing on a layer? Or is there another, better and/or simpler way that I am missing?

I have been looking at the YouTube tutorials and on line resources for weeks now, but can’t find the solution to my particular question. Thanks for reading. Any suggestions would be appreciated.

Since you are using Make, you can trace an imported image of the contours. You could use a pen and tablet or just use the mouse. The results can be the same. Zoom in and work on small areas. It’ll help you draw edges that are slightly off axis.

DO NOT create separate layers for each contour. Do all of the drawing on Layer 0 and keep all edges and faces there.

Your question about layers indicates you aren’t familiar with how layers work in Sketchup. You probably ought to spend some time looking at the help articles about Layers.

Is this a just for fun sort of project you’re working on?

SketchUp Make and Pro support COLLADA (*.dae) import.
Nonetheless, I would follow @DaveR’s advice.
Bring a raster image into SU and trace it.
That way, you have complete control of the geometry.

Thank you for the information. I am new to SU, but have used Corel and Photoshop for years. Not sure quite what you mean by “drawing edges off axis” and there is no information when I searched for the term?

I’m not familiar with layers in SU. I just read some of the help pages which seem straight forward. Was there something specific you had in mind?

This is for a community project involving the local primary school. I also want to see if I can do it!

Thanks again for reading my question.

SketchUp is a 3D modeling program. Since you are creating 3D shapes ona 2D screen, it uses inferencing to guide you. If you are drawing a line that is close to being parallel to an axis line (the red, green and blue lines on the screen) SketchUp will tend to assume you want the edge parallel to that axis and snap the line on axis. Zooming in close can make it easier to draw lines that are slightly off axis because the endpoint displacement on screen will be proportionally greater.

Yes. Layers in SketchUp are not like layers in Corel or Photoshop. In SketchUp they do nothing to provide separation between entities. There would be nothing to be gained by putting contours on different layers. You must use groups or components for separation. In the case of the contours, though, you don’t want to group them separately if you want to create terrain from them.

rise of 260 meters in run of n X 20 meters is a slope of about ?? degs .
If math is correct that results in many more than 20 samples for say a 10 deg slope. tan (260meters \20n meters) = 10degs / 180 degs /rad or N~233 samples. Of course using a larger slope will be less samples
Is that some what you intent.? ; Even if you are implying you want 19 sample points between that run you may have a challenge. Some of the image processing programs have an edge detection algorithms that may help but they are not very accurate but may make you drawing effort easier.
I would aslo consider using MeshLab it has many different filters for smoothing data and creating meshes but question if the data you are trying to use maybe way under sampled. Can you post image here with info on how many sample points per contour and what the steps are?
Just SWAG on thoughts:grimacing:

Thanks for the reply. I’m learning, but the curve is very steep… Unlike my contours. I didn’t explain it very well. The contour interval is 20 metres. Lowest is 40, highest just over 300, so 19 intervals, but over a ground distance of 3 x 5 kilometres.

I imported my Corel drawing as a TIF, then drew the contours over the basemap. scaled to 10%, so with an SU axis dimension of 30 metres x 50 metres.

There are 2,546 entities. Is that what you mean by sample points? I uploaded the flat drawing, as I started to try and lift the individual lines to scale with the drawing, but it didn’t go well.

I have found and viewed all sorts of tutorials, but none take you from blank sheet to finished TM, so I am going step by step. I’ll take your advice on MeshLab. All advice gratefully received :slight_smile:

Contours scale draw.skp (1.7 MB)

OK. That’s a start. The thing is, you need to complete the contours out to the edges of the rectangle. Then you should get faces that can be extruded upward. Look closely at your contour lines. Some of them have some extra edges.Look at that rightmost loop, second contour, for example.

You can see I’ve done a few of them here. The edges show thin when the contours form loops.

I just pulled a few of them up with Push/Pull. The interval was just a random distance but you would use your elevation interval.

1 Like

Like @DaveR says, there are numerous errors that will create problems.
I’ve flagged most in this copy of your model:
Contours scale draw_errors.skp (1.7 MB)

Hi @NormanW

You’ll achieve a more orderly TIN by moving endpoints around with the Move tool.
That is, try to have the line segments of adjacent contours roughly mirror each other.

Eliminate unnecessarily short line segments by simply dragging their endpoints together.
You’ll need to explode the curve entities first before you can work with their individual line segments.
Select All > Right Context click on the selection > Explode Curve


more of same

Sorry did not keep skp file:sleeping:

Thank you everyone for all the excellent advice, and especially for opening and critiquing my efforts.

I will do some more reading, then work and let you know how I get on.

I really appreciate the super quick and knowledgeable replies.