3D photo-realistic rendering: Diffusion, ray-tracing

I want to create a photo-realistic, static rendering of a room's interior. I want to know what options I have for open-source renderers. It does not have to render quickly. Initially I experimented with sketchup and photo renderer plugins, but they are costly and in my opinion clunky compared to what could be done with programming, plus features and quality seem to be hit-and-miss. I need the following capabilities:

Diffusion

• e.g. translucent frosted glass

Material tint

• e.g. tinted car windows

Reflections

• Mirror-like: e.g. Coloured materials with a semi-reflective, smooth surface
• Diffuse reflections e.g. ambient light created by point-light reflecting off walls

Shadows

• e.g. non-point-light shadows of an object that produce a shadow with soft edges

My preferred solution would be programmed in WebGL. Would it be capable of doing the above? I'd be particularly enthused with high-level libraries or similar which would be quick to program with.

Thanks

Can be done. You might want to have a look into Learning WebGL for the WebGL core essentials or three.js if you prefer a framework to work with.