well for the scale i m making a bathroom CAD software for the compagny i work for ( actually making this for me to make my work easier )
all the models are using this scale and i need precision i could always use 1 = 1 meter but... i bothers me ... i hate small numbers when debugging :p
the links you gave me could be usefull for the photorealist rendering for a single frame but with all the objects i will be dealing with when actually using the software i d like to keep the calculation low for FPS'sake ( all the computers it will run on are pretty basic )
that s why i m sticking with shader model 2
i m only looking for a nice way of lighting my scene and have shadows ( internal stencil gives me way too much artefacts )
or maybe it s the models that are buggy :/ converting from DWG autocad
I'm not sure what you mean by 1 unit = 1 metre and then you hate small numbers? -- a metre is larger than a millimetre. The issue is with rendering precision, you're going to have problems if you insist on 1 unit being 1mm. We often say that scene scale is rather abstract and dependant on the project/person. But there are still limits.
You can do HDR in SM2. It doesn't really matter how many models you have in your scene, this is post. All that matters is what you render and send through the pipeline.
The lighting and shadows, well, that's a very very wide subject. Could spend years discussing and talking about different techniques( particularly shadowing ). The trouble is I don't really know what CAD software entails. So my only real suggestion is to start writing small shader samples, get a feel for HLSL if you haven't already, then start working on ideas that suit you and your project. There is really no finite solution to these questions, particularly when it comes to shadow(mapping).
