# Terrain to solid model without extensions?

**URL:** <https://forums.sketchup.com/t/terrain-to-solid-model-without-extensions/315250>\
**Category:** Pro\
**Tags:** modeling\
**Created:** [February 20, 2025, 7:31pm UTC](https://forums.sketchup.com/t/terrain-to-solid-model-without-extensions/315250 "2025-02-20T19:31:05Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![vitabaltram](https://avatars.discourse-cdn.com/v4/letter/v/f1d935/32.png) [@vitabaltram](https://forums.sketchup.com/u/vitabaltram)\
**Post date:** [February 20, 2025, 7:31pm UTC](https://forums.sketchup.com/t/terrain-to-solid-model-without-extensions/315250/1 "2025-02-20T19:31:06Z")

</div>

Is it possible without using any extension from external providers to create solid/volume/skirt from terrain, which was made using contours and sandbox tool?

 ![image](https://global.discourse-cdn.com/sketchup/original/3X/4/b/4b01b2fc6bac1cdd1e437cbc8ae71e26c510883b.jpeg)

---

<div class="post-metadata">

**Author:** ![ateliernab](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/ateliernab/32/198399_2.png) [@ateliernab](https://forums.sketchup.com/u/ateliernab)\
**Post date:** [February 20, 2025, 7:36pm UTC](https://forums.sketchup.com/t/terrain-to-solid-model-without-extensions/315250/2 "2025-02-20T19:36:17Z")

</div>

by hand. you see the red outline you have ?  
using the drape tool from the sandbox, you could drape it onto a flat face below the terrain. then, all you’d need to do is use the line tool to trace all the vertical lines (dashed blue in your image). each line should close a face, and when you’ve gone all around, you should get a volume.

but if you’re using the sandbox tool it means you’ve got a pro version, and you can get this free extension that’ll make it for you in a couple of clicks.

> **[SketchUp Extension Warehouse](https://extensions.sketchup.com/extension/71021899-fff7-44e9-87ef-14b79ecbd3b9/eneroth-terrain-volume)**
>
> Your library of custom third-party extensions created to optimize your SketchUp workflow.

---

<div class="post-metadata">

**Author:** ![jean\_lemire\_1](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/jean_lemire_1/32/665_2.png) [@jean\_lemire\_1](https://forums.sketchup.com/u/jean_lemire_1)\
**Post date:** [February 20, 2025, 7:46pm UTC](https://forums.sketchup.com/t/terrain-to-solid-model-without-extensions/315250/3 "2025-02-20T19:46:31Z")

</div>

Click in sequence on the scenes tabs of this SU file that I created in 2013 using only native tools (Sandbox Tools).

[Box under topo.skp](https://forums.sketchup.com/uploads/short-url/qfEiUOecuIkyuxtVllzXiNwslwn.skp) (44.7 KB)

---

<div class="post-metadata">

**Author:** ![ateliernab](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/ateliernab/32/198399_2.png) [@ateliernab](https://forums.sketchup.com/u/ateliernab)\
**Post date:** [February 20, 2025, 7:57pm UTC](https://forums.sketchup.com/t/terrain-to-solid-model-without-extensions/315250/4 "2025-02-20T19:57:07Z")

</div>

oh yeah, even better. I usually deal with square terrains, so it’s simply “draw the vertical lines on the four corners” but with a complex terrain, your solution is way better !

---

<div class="post-metadata">

**Author:** ![eric-s](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/eric-s/32/55392_2.png) [@eric-s](https://forums.sketchup.com/u/eric-s)\
**Post date:** [February 20, 2025, 10:31pm UTC](https://forums.sketchup.com/t/terrain-to-solid-model-without-extensions/315250/5 "2025-02-20T22:31:19Z")

</div>

Intersect with selection. Delete top half.  
 ![Feb-20-2025 14-30-54](https://global.discourse-cdn.com/sketchup/original/3X/c/f/cfd987c0cbab8c6d1e5c04f32c98570d44f1f12c.gif)

To make solid, explode terrain surface and group with base geometry.

 ![Screenshot 2025-02-20 at 2.32.26 PM](https://global.discourse-cdn.com/sketchup/original/3X/4/d/4d248a3db0c5c5fc78ae03398815c53bccd29bfc.jpeg)

---

<div class="post-metadata">

**Author:** ![vitabaltram](https://avatars.discourse-cdn.com/v4/letter/v/f1d935/32.png) [@vitabaltram](https://forums.sketchup.com/u/vitabaltram)\
**Post date:** [March 4, 2025, 12:55pm UTC](https://forums.sketchup.com/t/terrain-to-solid-model-without-extensions/315250/6 "2025-03-04T12:55:32Z")

</div>

Thank you - it works nicely!