SketchUp AI render prompts that keep your geometry

An image model sees pixels, not a SketchUp file. It does not know that a black line is an edge, that a red line is an axis or that a flat grey face is a wall. When it is unsure, it guesses, and a guess about a roof or a window grid is a redesign.

Three things in a typical SketchUp capture cause most of it. Heavy black edges and profiles read as trim or frames. Untextured faces read as unfinished, so the model invents detail. The default sky-and-ground background gives no site context, so the model adds its own, sometimes a slope that changes the building's base.

The fix is in two places. Clean up the capture in SketchUp, then write a prompt that names what is left.

Open the Styles panel (Window > Default Tray > Styles on Windows, Window > Styles on Mac), click the Edit tab and set the options below. Save it as your own style so every scene uses it. The style does part of the prompt's job.

Even with a clean style, some marks get through. Name them by what they look like, not by their SketchUp name. The model has never seen your toolbar.

• The red, green and blue axis lines crossing at the origin.
• Dashed construction lines and guide points from the Tape Measure tool.
• The section plane rectangle and its cut edges.
• The blue selection box or highlighted faces from a selected group.
• Black edge and profile lines along every corner.
• Back edges shown as dashed lines through walls.
• The default scale figure, if you want it gone rather than turned into a real person.

Locking means giving the model numbers it can compare against your screenshot. Count before you write. A prompt that says 'keep the 2 floors and 7 windows on the street face' holds better than 'keep the design'.

Lock the camera in words too. SketchUp's Two-Point Perspective keeps verticals upright in the capture; tell the model to keep them that way, or it may add the slight lean of a phone photo.

Then check the result the same way. Open the screenshot and the render in any image editor, put the render on top at about 50% opacity and look at the roofline, the window heads and the corners. If they line up, the lock held. If a window jumped one bay or the eaves moved, add that element to the prompt by name and run it again. Counting takes a minute and saves several reruns.

• Floors: Exactly two floors above ground. No attic, basement windows or roof terrace.
• Openings: Seven windows and one door on the street face, in the same positions and sizes.
• Roof: Hipped roof with the same pitch and overhang. Do not add dormers or skylights.
• Structure: Keep the column spacing and the four bays of the carport.
• Camera: Same eye height, lens, crop and horizon as the screenshot.
• Verticals: Every vertical edge stays vertical and parallel.

SketchUp's default colors mean nothing to an image model. A pale tan face could be render, stone or plywood. Write one material per element and include color, finish and joint pattern where it matters. Keep the list short; four or five elements is plenty.

Tie each material to a place the model can see: the upper floor, the base, the left wing, the porch soffit. 'Cedar on the walls' gets applied to every vertical face, including the chimney. If two elements share a SketchUp color, name the difference, or paint them differently before you export.

Edit the counts and materials to match your screenshot. Leave the structure of the sentences as it is.

• This is a SketchUp screenshot (Image 1). Produce a photoreal exterior photo of exactly this house. Image 1 is the authority for form and camera: two floors, hipped roof, seven windows and one door on the street face, the carport on the right, same eye height and horizon. Delete the red, green and blue axes, the dotted construction lines and the black edges. Materials: cedar boards on the upper floor, pale limestone below, dark standing-seam roof, black window frames. Midday sun from the right with crisp shadows. Keep verticals straight. No text or watermark.

Interiors fail differently. The model moves furniture, widens windows to let in more light and adds ceiling fixtures. Lock the layout and the openings, and say where the light comes from. If your SketchUp model has placeholder furniture, name each piece so it is replaced in place rather than removed.

• Image 1 is a SketchUp interior view. Make it a realistic interior photograph of the same room. Keep the room shape, ceiling height, the two windows on the left wall, the doorway at the back and the camera exactly. Keep every piece of furniture where it stands: sofa against the right wall, low table in front, dining table with four chairs by the windows. Finishes: oak floor, white plaster walls, linen sofa, black steel pendant over the table. Daylight only through the existing windows. No new openings, lamps or text.

For night, start from a daytime render you already approved, not from the raw screenshot. Changing materials and light in one step is where geometry slips. Say which windows glow and which fixtures exist; otherwise the model lights every pane and adds wall sconces.

• Turn the daytime render in Image 1 into a night photograph from the same camera. Do not change the house, roof, windows, carport or planting. Warm interior light in the three ground-floor windows and the left upstairs window; the others stay dark. One light over the front door, as modeled; no other exterior lights. Dark blue sky, a soft glow from the windows on the path. Glass shows faint reflections. Keep the framing and straight verticals. No text.

Yes. ArchFor is a web app that turns 3D model screenshots, sketches and existing renders into photorealistic architectural images. Credit packs from $9.99; no plugin and no subscription required. You do not write prompts. You pick Model screenshot as the input, then Exterior or Interior, one of six styles and Day, Golden hour or Night.

The SketchUp recipe already removes axes, guides, section planes, selection outlines and black edge lines, and treats your screenshot as the authority for massing, floor count, openings and camera. The one-line materials note (up to 200 characters) is where your per-element materials go, for example 'cedar boards upper floor, limestone base, dark standing-seam roof'. It changes materials and details, not form.

Each click gives 4 options at 1K, 2K or 4K. From a result, Night makes the night version from the image you chose, checked against your original upload. Results are AI images: small items such as railings can shift, and they are not for construction documents. SketchUp is a trademark of Trimble; ArchFor is not affiliated with Trimble.