Evaluation · 2026-11-03
How we test ArchFor renders
Before choosing the image model behind ArchFor, we ran every tool on the same 12 test inputs with both candidate models and scored each image by hand. This page shows the scores, the rule we used and the failures.
What we tested
Twelve synthetic inputs built in three.js so that anyone can check the geometry: SketchUp-style screenshots, clay models, line sketches, 2D elevations and real-time render exports of a house, a townhouse, a two-story box, a room and a garden. Each input ran once through the production recipe with Nano Banana 2.1 and once with Nano Banana Pro, at 2K, with no retries and no editing.
Every image got 0, 1 or 2 points on four questions:
- Geometry: are the massing, openings and camera the ones in the upload?
- Realism: would it pass as a photograph at screen size?
- Artifacts: no melted edges, floating objects or broken backgrounds?
- Preset match: does it show the style, time or action chosen?
An image counts as usable only when geometry scores 2 and the total is at least 6 out of 8. A beautiful image with an extra window is not usable for a client review.
Results by tool
| Tool | Nano Banana 2.1 (used) | Nano Banana Pro (not used) |
|---|---|---|
| Model → Render | 5 of 8 usable | 6 of 8 usable |
| Render Enhancer | 4 of 4 usable | 1 of 4 usable |
Our rule: keep the cheaper model when it is usable on at least as many inputs as Nano Banana Pro, or within one. Nano Banana 2.1 was, for both tools, and Nano Banana Pro was not better overall, so ArchFor now runs Nano Banana 2.1 only. You choose the image size instead: 1K, 2K (default) or 4K.
Where Nano Banana Pro was better: clay models. On both clay inputs Nano Banana 2.1 invented a detail (a roof overhang, an extra window), and it did the same on two more clay models in the page samples. We rewrote the clay instructions to say that each recessed rectangle is exactly one opening and that a flat roof stays flat, then ran all 4 clay inputs again on Nano Banana 2.1: 4 of 4 kept every opening. That corrected recipe is the one the site uses now.
Every input and score
| Input | Settings | Nano Banana 2.1 | Nano Banana Pro | What we saw |
|---|---|---|---|---|
| House, SketchUp-style screenshot | Model → Render · Exterior · Warm timber · Day | 8/8 · usable | 8/8 · usable | Both kept the six openings, porch and roof pitch. |
| Room, interior screenshot | Model → Render · Interior · Scandinavian · Day | 7/8 · usable | 7/8 | Nano Banana Pro turned the wall panel into a window; Nano Banana 2.1 kept it but left the room open to the sky, as in the model. |
| Two-story box, clay model | Model → Render · Exterior · Concrete & glass · Golden hour | 7/8 | 8/8 · usable | Nano Banana 2.1 added a roof overhang the model does not have. |
| Townhouse, clay model | Model → Render · Exterior · Modern minimal · Day | 7/8 | 8/8 · usable | Nano Banana 2.1 added a third upper window. |
| House, line sketch | Model → Render · Exterior · Mediterranean · Day | 8/8 · usable | 6/8 · usable | Nano Banana Pro placed the house on a floating terrace. |
| Room, line sketch | Model → Render · Interior · Industrial · Day | 7/8 | 6/8 | Both reinterpreted the low platform; neither is usable. |
| Townhouse, 2D front elevation | Model → Render · Exterior · Warm timber · Day | 8/8 · usable | 6/8 · usable | Nano Banana Pro left half of the background white. |
| Two-story box, 2D front elevation | Model → Render · Exterior · Concrete & glass · Day | 8/8 · usable | 7/8 · usable | Both kept the three upper windows and the glazed base. |
| House, real-time render | Render Enhancer · Make it photoreal · Balanced | 8/8 · usable | 7/8 | Nano Banana Pro added posts under the door canopy. |
| Two-story box, real-time render | Render Enhancer · Night · Balanced | 8/8 · usable | 8/8 · usable | Both usable; Nano Banana 2.1 lit the interiors more convincingly. |
| Townhouse, real-time render | Render Enhancer · Add people · Balanced | 7/8 · usable | Failed | The Nano Banana Pro job failed at the provider (refunded in the product). One figure on the balcony looks pasted in. |
| Garden, real-time render | Render Enhancer · Replace sky · Balanced | 7/8 · usable | 4/8 | Nano Banana Pro reflected the new sky in the lawn and the base of the model. |
Three comparisons
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Nano Banana 2.1
Nano Banana Pro
Upload
Nano Banana 2.1, first recipe
Nano Banana 2.1, corrected recipe
Upload
Nano Banana 2.1
Nano Banana ProPage samples and adjustments
We then made one Nano Banana 2.1 image for every tool page that had no image from the comparison: 13 of 17 were usable on the first try.
- Two clay models gained windows (fixed by the corrected clay recipe and re-run).
- One garden render lost a tree and one gained a soil edge under the lawn; both were run a second time and the second image is shown.
Finally, we ran each one-click adjustment on a finished image, with the original upload attached so the model can check the geometry:
| Adjustment | What we saw |
|---|---|
| Brighter | Kept geometry; the change is mild, about half a stop. |
| Moodier | Kept geometry, but the change is hard to see. For a clear change of mood, use Night, or render again at Golden hour. |
| Night | Kept geometry; lit interiors and a blue-hour sky. |
| Add people & planting | Kept geometry; four people at the right scale, no blocked entrance. |
| Change facade (brick) | Kept openings and frames; both stories became brick. |
| More like this | Kept geometry and layout; small changes in styling. |
Limits of this test
- One image per model and input. A real round gives four, so your odds of at least one usable image are higher than these single-image scores.
- Synthetic models are simpler than real projects. Dense facades, curved forms and furnished interiors were not part of this round.
- One person scored the images; the scores are judgment.
The before-and-after pair on each tool page comes from this test: a Nano Banana 2.1 image at 2K, not retouched. Try it on your own model.