Tervika

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From Coordinates to 3D Render: A Tervika Workflow

9 min read

This article walks through one real project from start to finish — a fingerpost sign for a lakehouse in southern Sweden. It's the kind of project Tervika exists for: a private location, a handful of personal destinations, and a maker who wants the sign to point correctly without spending a weekend doing trigonometry.

I'll cover the full workflow: choosing the destinations, setting up the Master Template, iterating on the 2D and 3D previews, and exporting the file the workshop actually needs. The article assumes you've already poked at Tervika once or twice; if you haven't, the Get Started page is the better entry point.

The brief

The lakehouse sits on the edge of a forested lake in Småland. The owner wanted a sign at the path junction near the boathouse, pointing at:

Seven plates, two posts of which were obvious in hierarchy (the long-distance ones go to the bottom, the close ones go to the top), and a wide range of distances. The plate at the top would be visible from a metre away; the plate at the bottom would be visible only when someone bothered to look.

That dynamic range is what makes a real fingerpost interesting, and it's what makes most of the design decisions.

Step 1: Pick the location

The single most important number in the whole project is the GPS coordinate of the sign post. Every plate's bearing and distance is calculated from that point. If you set it 50 metres off, the nearby plates' bearings drift visibly; if you set it kilometres off, even the long-distance bearings shift.

Three ways to set the location in Tervika:

I used "tap the map" zoomed in on the boathouse area. With satellite imagery, you can identify the path junction visually and tap the exact spot. Tervika captures the coordinates in decimal degrees and stores them as the sign's "home" location — every plate's bearing and distance is computed from this point.

A small habit: once you've set the location, look at the resulting decimal coordinates and check that they're plausible. A typo or misplaced tap can put you in a different country, and you won't notice until the bearings look strange. The lakehouse was at 56.78°, 14.91°. Anything significantly off would have been a red flag.

Step 2: Set up the Master Template

The Master Template is where you set the defaults that all plates inherit. Setting it up first saves you from re-doing the same decisions seven times.

For this project I set:

The Master Template is what you tweak when you change your mind globally. The per-plate overrides are for when one specific plate needs to be different.

Step 3: Add the destinations

Each plate is one destination. The workflow is the same every time:

  1. Search for the destination (or tap on the map).
  2. Tervika calculates the bearing and distance from the sign location.
  3. Optionally override the destination name (the search result might give you "Tokyo, Japan" when you want "Tokyo").
  4. Optionally adjust the plate length so the text fits properly.

Three things that always come up at this stage:

Plate length follows text length. "Sauna" fits comfortably on a 400 mm plate at 35 mm cap height. "Daughter in Berlin" needs more like 700 mm. The 600 mm default from the template is for medium-length destination names; longer names need their own plate length, set as a per-plate override.

Some destinations are vague. "The boat dock" doesn't have GPS coordinates in any database. For these, tap the map at the actual dock location. Tervika doesn't care whether the destination is named or not; it cares about the coordinates.

Distance scaling reveals plate hierarchy. Once all seven plates are in, the distance values cluster into three groups: under 100 m (cabin, sauna, dock), 1-2 km (friend's cabin), and 300-8000 km (the long-haul ones). That clustering tells you exactly how to order the plates on the post — close at the top, mid-range in the middle, long-haul at the bottom.

Step 4: Iterate in 2D

The 2D side view is where you check whether the sign reads as a sign. Two things to look at:

Proportions. Are the plates the right size relative to the post? A post that's too tall or too short throws the visual balance. Tervika lets you set the post height in millimeters, and the 2D preview updates instantly. For this project I tried 2200 mm, then 2400 mm, then settled on 2300 mm — long enough to space the seven plates with breathing room, short enough that the top plate isn't above eye level.

Plate ordering and spacing. Stand back from the screen and look at the silhouette. Does the eye flow naturally from top to bottom? Are the plates evenly spaced? If you've set the order by distance (close on top), is the visual weight balanced? On the lakehouse sign, the long Tokyo plate at the bottom needed a slightly larger gap above it to keep the bottom of the post from looking crowded.

The 2D top-down view is where you check whether the sign reads as accurate. The compass overlay shows true north and the cardinal directions. Each plate appears at its actual bearing, drawn as a small arrow radiating from the post. If you know roughly where the destinations are, you can sanity-check the plate angles against your mental map.

For the lakehouse, the close destinations clustered to the south (the cabin, the sauna, the dock are all south of the sign). The friend's cabin plate pointed east. Stockholm pointed approximately north (about 5° east of true north — the great-circle path is essentially due north for that distance). Berlin pointed at about 200° (south-southwest). Tokyo pointed at about 50° (east-northeast — which surprises people who haven't seen great-circle paths before; the line to Tokyo bends way north over Russia).

If the top-down view shows a plate pointing in a direction that doesn't match where the destination is, double-check the destination's coordinates. Almost always the issue is a wrong city in the search results, not a calculation error.

Step 5: 3D preview for the client

The 3D preview is the conversation tool. It's not for making manufacturing decisions — that's what the 2D side view is for. It's for showing the client what the finished sign will look like in their environment, so they can react before you cut anything.

For this project, I sent the owner the 3D model — a GLB file exported from the editor — and asked them to look at it on their phone in the actual lakehouse setting. They came back with two notes: "Berlin" was misspelled (an extra 'l' I'd missed) and "Tokyo" should read "Tokyo, Japan" because their Swedish friends might be confused otherwise.

Both changes took thirty seconds in the editor, and the 3D preview updated immediately.

The 3D preview also catches scaling problems that the 2D views can hide. Plates that look reasonable on the screen sometimes look comically small relative to the post when you see them in 3D, because the 2D view is normalized to the screen size. The 3D preview shows the actual proportions.

Step 6: Export for the workshop

Once the design was finalized, the export step produced three files:

For the lakehouse the CNC operator was a friend with a Shopbot. The DXF imported cleanly into VCarve, and the toolpaths — pocket-engrave for the text, profile-cut for the plate outlines — were generated in about ten minutes. The total cutting time across seven plates was about three hours. Sanding, oiling, and assembling the sign took another afternoon.

Step 7: AI prompt for the marketing visual

Tervika has a feature that I didn't expect to use much, but ended up being the most fun part of the project: the AI prompt generator.

The feature takes the sign design — coordinates, plates, dimensions, materials, colours — and writes a structured prompt for an image generation model that describes the sign accurately. You can paste the prompt into Midjourney, DALL-E, ChatGPT-image, or any other generator, and get back a photorealistic render of the sign in a chosen environment.

For the lakehouse I generated three images: the sign at golden hour by the boathouse, the sign in mist on a cool morning, and the sign in winter under a thin layer of snow. None of these are accurate to a single specific real moment — they're imagined photos. But they're useful for showing the client what the sign might look like across seasons, which is something a 3D render in studio lighting can't do.

A small caution: AI-generated images are interpretive. They get the general shape right but the plate details — exact text, exact ordering, exact proportions — are approximations. Use them for atmosphere, not for proofing.

What the whole thing took

End to end, from first opening Tervika to handing over the DXF: about three hours of design time spread over two evenings, plus the exchange with the owner about Berlin and Tokyo. The CNC cutting took half a day. The finishing and assembly took an afternoon.

The sign has been up for eleven months at the time of writing. The wood is starting to silver in the way Swedish cedar does. The bearings are still right because the planet's rotation is reliable. The owner reports that visiting friends regularly stand in front of the sign for a while, working out which plate points where they came from.

That last part is, fundamentally, what a good directional sign does: it makes people slow down, look around, and notice the geography they're standing in. Tervika is the tool that makes the sign correct. The conversation it provokes afterwards is the reason to build one.

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