Light simulation tools like Radiance and traditional 3D rendering engines differ mainly in their core goals: Radiance prioritizes accurate physical light calculation, while traditional engines focus on visual realism and rendering efficiency.
Radiance is built to simulate light behavior based on physical laws, making it ideal for precise lighting analysis in architecture, daylighting studies, or energy efficiency projects where accurate light data is critical.
Traditional 3D rendering engines, such as Blender Cycles or V-Ray, optimize for fast, visually appealing outputs, suited for gaming, animation, product visualization, or marketing where realistic visuals and quick turnaround matter most.
In short, choose Radiance for technical lighting performance data; opt for traditional engines when visual presentation is the priority.