HDRI Environment Shadows

I am experimenting with HDRI scene lighting and seem to be having trouble when using high contrast images to achieve shadow edges with greater definition. I can only get soft edges unless I enable the physical sun. Is this the only way to achieve crisp shadows in Rhino? (I can get shadows with high edge contrast using the same HDRI images using Maxwell.)

test_hdri test_sun

I think it depends on the HDRI and it’s dynamic range. Exterior scenes with the sun visible would be more likely to create a dramatic shadow using the HDR for the env. lighting versus an interior scene with lots of typical lights and overall even lighting. In the Rhino 6 env. library I think ‘Incheon airport’ and ‘RDJ window’ probably have the highest dynamic range but you still won’t get a hard shadow like you would with the sun on. I like a combination of HDR for reflections and actual lights for controllable hard shadows. The renderer used is also a factor.

Thank you for clearing this up so quickly. I have been placing lights to get hard shadows like you suggested that obtain the desired effect. My only question is does it ultimately boil down to the renderer? I can use the same HDRI image using Rhino Render and my Maxwell plug-in and achieve totally different results with what I believe are very similar settings. I suppose this should be obvious to me but since I’m using the same HDRI images I was just stumped. I also thought the size of the light source had a great affect on the quality of shadows as well.

That is a factor for sure in my experience, I would bet Maxwell does more with the HDR then Rhino Render but I currently don’t have a working Maxwell to compare.

For rectangular lights this will certainly be true… the size of the rectangle and it’s distance from the model will influence the sharpness of the shadow edge.