21 / INTERIOR DESIGN / CAD-TO-RENDER VISUALIZATION

A pipeline that turns a CAD floor plan directly into a full set of photorealistic marketing renders.

Client: Mid-sized interior design firm

Tags: Interior Design · CAD Automation · Generative AI · Architectural Visualization · Real Estate Marketing

// Problem

Handed a raw CAD floor plan, an end client sees lines, labels, and geometry — not a home, and not something they can picture themselves living in. The old fix was a 3D animation or walkthrough built by hand for every plan, and even after that effort, it still looked stiff and artificial, never like a real photograph. And that manual process had to start over from scratch for every new layout and every revision.

// Our Solution

A way to turn a CAD floor plan straight into photorealistic images that actually look like real photos of a finished space. The floor plan is read automatically and turned into a full set of finished renders — a hero shot, an overhead view, a full-house cutaway, a close-up of the best room, and an evening shot — each one convincing enough to use in real marketing. And because it's automated, the team can now try different angles, lighting, shading, and furniture styles for the same plan without starting the manual 3D process over from scratch.

// Technical Details

CAD Ingestion & Semantic Summarization

A DWG floor plan is converted to DXF and parsed into structured entity data, then compressed by a dedicated summarizer from a raw dump that can run past 100,000 characters down to a 2-4k character summary an LLM can actually reason about — deduplicated layer names, extracted room-label text, a bounding box with an automatic meters-vs-millimeters scale heuristic, wall/polyline complexity, and fixture counts.

Topology-Preserving Geometry Description

An LLM turns that summary into an 8-12 sentence geometry description — dimensions, room positions by cardinal position, wall construction, fixture locations — under an explicit instruction to preserve the plan's actual topology rather than let the model take creative liberties with room placement.

Five Engineered Rendering Prompts Per Plan

Five fully-specified photorealistic prompts covering a hero interior perspective, a photorealistic top-down plan view, an isometric dollhouse cutaway, a room-specific close-up, and a twilight exterior-interior shot — each one required to specify materials, cinematic lighting, camera height and framing, staging, and a consistent set of render-quality keywords.

Automated Rendering with Resumable Batches

An image-generation model renders each of the five prompts per floor plan automatically, with retry and exponential backoff on failure and a skip-if-already-generated check, so a batch of floor plans can be queued and left to process without babysitting.