Modelling Basic Property Topography

I wish to model my yard. For the most part it is a very basic rectangular lot, but along the back of the lot (50’) there is a very basic sloped hill. It rises 31" from the level part of my property, out 221" from the rear lot line.

What is the best approach to model this terrain, considering I wish to add a retaining wall into the hill, and model the structures that sit in my lot (on the level portion). How about simply stretching a triangle along the back of my property 31" high, with a 221" base running the 50’ length? This would provide unrealistically sharp edges.

How about sharing some hand drawn sketches to show which is what? And maybe the file of what you have got sofar?

Thank you Wo3Dan for stepping up to offer some help.

I’ll share this sketch. It’s not really complicated. I don’t have a sketchup file yet, other than a rectangle of 50’x120’, my lot. My next action, i think, will be to add the hill before I start placing any structures or components.


The blue dash-dot-dash is the botton of the hill. 221" from the rerar property line.
The dashed lines are pseudo topopgraphical lines. They kinda illustrate the steepness.
The sketch at the bottom is a profile sketch along the right property line, A is the base of the hill, and B is the crest of the hill, a difference of 31".

On the left side of the sketch, the left property line also has a small hill. It extends 81" out from the property line. At the front (where the orage 81" is), the elevation differencer is 18". At the back, the elevation is 31". The rear left corner is basically a part of a bowl.

I hope this kinda helps.

I’ve attached a file of a conceptual approach to doing this. This illustration below tries to show where I am lacking the skills to do what is necessary.

The side hill, in addition to slopping from front (0") to back (31") - as illustrated - it also needs to slope from right (0") to the left property line, at at elevation of 31" at the rear, and 0" at the front. This I am unable to do. Of course, the side hill will merge into the rear hill.

I would like to “soften” these edges and faces to reflect a more natural landscape feature.test1.skp (121.4 KB)

See next screenshot as an option to get the basic shape done, (basic tools like in SketchUp Free):

I started with a rectangle 1440"x600"

Split off 221" with edge through A
Split off 81" with edge through C

Draw vertical edge towards B, length 31"
Draw vertical edge towards D, length 18"

Create an arc from B to A, tangent to the longer lot side (blue when tangent)
Create an arc from D to C, tangent to the shortest lot side (again blue when tangent)

Group each enclosed vertical face (the arc shaped triangles) separately
In group’s editing context push the vertical faces to the respective other sides.

Now its a matter of scaling either side of the longer slim shape to meet the desired heigth at front and back of the lot.

7.4" could even be reduced when scaling down further.

In the end the groups can be exploded to then apply “Intersect Faces with Model” to intersect both curved surfaces.

Thank you so much G.H. Hubers. Your instruction provided exactly what I had asked for. Now that its sketched out I think I need to do some tweaking as a result of poor explanation on my part. With this accomplished, I see that the top left corner where the two hills intersect should really have a bit of a plateau on it. Shrug.

I did notice, that after intersect faces was applied the the selection of both hills, that I’m getting some unusual artifacts on the left hill. Is this something that needs to be accepted, or is there a way to get rid of that?

test2.skp (115.0 KB)

You could start with Follow Me around the two sides and then scale the geometry at the back to make the longer slope.

Hi Dave,
I thought I would take an opportunity to learn some new skill by applying your suggestion.
I’ve attached my model.
I constructed the face of the small hill, 81" out, 18" high and used the follow me tool to follow the left and rear (property) lines
Now, I’m having trouble creating the hill at the back from it. I used the scale tool to adjust the hight (31") and dept of the rear hill (221’) using the opposite face of the extrusion. (In my attached image it would be the white face).
I think I’m missing a critical step as this scaling did not get applied to entire length of the hill, and the rear left corner didn’t adjust in height. It should be 31", this the left hill will go from 18" to 31" front to back. The rear hill is consistently at 31" high.

test4.skp (145.5 KB)

Use Scale tool for certain portions and don’t forget to add the unit of measure to the dimension to resize exactly

Thank you everyone. I finally got it! Everyone contributed a little bit to the final solution with each person’s suggestion. It was additionally a great learning opportunity. :+1:

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try using the add location tool and look at terrain