Brixx, Brno: 3D reconstructions
Three ways of turning four marketing renders of the Brixx development into a 3D model, compared on the same views. All models open in the browser; drag to orbit.
Astra, procedural Blender model
An agent (gpt-6-astra) derived a site plan from the renders and wrote a Python script that builds every building in Blender.
- Clean, measurable geometry: storeys, balconies, railings, roofs
- Correct layout; facades are a regular, simplified pattern
- Looks the same from every angle
Astra, photo-projected textures
Same model, cameras refitted to the renders, then the renders themselves baked onto the surfaces (the idea behind image-blaster's use of the source image).
- Photographic facades near the four reference views
- Smearing and ghosting where geometry and render disagree, and on the ground
- Hidden sides keep the procedural colours
TripoSR, single image to 3D
Tripo's open-source model (MIT), run locally on one render at a time after automatic background removal. One result per input view.
- Fully automatic, about 2.5 minutes per image on a laptop GPU
- Blobby shapes, no straight walls or storeys, tower too short
- Each view gives a different, inconsistent model
image-blaster and hosted Tripo
image-blaster only orchestrates paid cloud APIs (World Labs Marble for a Gaussian-splat environment, Hunyuan 3D on FAL for objects) and needs keys for both. Tripo's hosted models need an account; the free plan is a small monthly credit allowance, non-commercial, with public models. Neither ran here.
Same views, side by side
Each row: the supplied render, the procedural model, the photo-projected model, rendered from the camera matched to that render.
Away from the reference views
The projected model from three viewpoints no render covers. This is where projection texturing breaks down.
TripoSR results
Left: the input after background removal. Right: the generated mesh from four directions.
