Lumion, developed by Act-3D B.V., was already known for its "real-time" rendering engine, which allowed users to see lighting, shadows, and materials update instantly. However, version 2.x and early 3.x releases were memory-hungry. The release of specifically optimized for 32-bit systems was a strategic move. It allowed users with 3–4 GB of RAM and older GPUs to access high-quality rendering without upgrading their entire workstation.
A 32-bit application can only address a maximum of $2^32$ bytes of memory, equaling 4 Gigabytes (GB). Lumion Pro 3.0.1 32 Bit