OTOY Forums

Sorry to both you Radience, I know you must be hard at work with the Beta but just wondering if the IBL system will have smart IBL characteristics so we can get hard shadows. Most of the examples so far have diffuse shadows I would be nice to use HDRIs and also get realistic shadow detail. Also looking forward to seing the sun/sky system in action. Octane looks to be shaping up nicely, think its going to be very impressive when its out there.

hi,

initially not, it's just a pure diffuse environment light.
i can probably add that pretty easily, but i'm not aware of existing techniques to configure it ?
i can probably add some for of mask that allows you to define the angle/width of the illumination ontop of the env map,
is this what you're asking ?

Radiance

Thanks for the reply. Im no expert but ASFIK the 'smart' bit features some form of importance sampling so the strength of the sun is actually realistic IE 1000's of times brighter than the rest of the sky. The problem with creating hdris is the fact that the camera can't pic this intensity up so people have developed ways within their software to intelligently boost the exposed areas more. Im not sure how they do it but its pretty wide spread the other engines I use are Fryrender and Vray and they both have it. It just makes a sunny hdri actually behave like a sunny hdri!

As a side point is Octane based on Radiance (so hence the forum name)? Ive met Greg Ward a couple of times cant believe he developed that like 20 years or so ago! The hardware then must have been hopeless, but he said he could get a render out over night which is impressive.

Cheers
Rob

hi,

no it's got nothing to do with the software called 'radiance'.
radiance has been my internet nickname since about 12 years, long before i was doing any 3d stuff.
it's a coincidence.

Radiance

sIBL adds standard lights in the host application (Maya, 3dsMax...) and positions this light at the brightest spot in the hdr map.

So it won't work in Octane for now. It's also limited to sunlit hdr, at least in Max+Vray, as it can only place one sharp light per scene.

By the way, it's perfectly possible to obtain very sharp shadows with an hdr map. I do it all the time. It should in fact be even easier in an unbiased renderer.

The conditions are: 1- always use a hi-res hdr map (bearing in mind the ram limitations of you card), 2- boost the contrast in a 2d editor if you have to by lowering the gamma value of the map, 3- let it cook long enough for the shadows to resolve.

thanks for clearing that up bdb,
it makes sense now.

i'll add this to my TODO list of features, it should'nt be too hard to implement that in the future.
although i can't make any guarantees as to when it will be implemented.

Radiance

It would be fantastic if you could sort a way for HDR lighting to produce sharper shadows without fireflys in the 3ds max plugin.
Here's hoping...