Splotchy IR Map

[alfienoakes]

I am a little confused on this one.. Maybe needs a fresh perspective on it.

 

I have a very simple model. There are 3 materials involved; 2 shades of grey, and glass. Thats it. There are no bitmaps, no lighting other than GI. There are no other materials than Vraymtl.

 

Thats it. I am getting splotches on my IR map, most noticeable during the calc phase. Not too bad once rendered, but once I start to apply proper materials, it will start to show up.

 

I have tried a few different things, image samplers etc.. and it still does it. I moved the model right on to the origin, and it still does it..

 

Any clues would be great..

 

Cheers

[Brian Smith]

well i'm pretty sure it's because of your high irradiance map resolution (max pass=0), combined with your low inter samples. the higher the irmap resolution, the smaller the noise (ie splotches) will be...the higher your hspsubdivs, the better colored (for lack of a better word) and less apparent your noise will be. the smaller the interp samples, the less blurred the splotches will be. so you have a high resolution and little blurring, which means smaller unblurred splotches. you would actually reduce the effect by reducing the irmap resolution, which is one reason why i like a medium preset (max pass=-1) because i dont have to set the hsph subdivs or interp samples so high. if you set the max pass to -3 for example you would have almost no splotches because the splotches woud be so large...you dont want to obviously do that for production renders cuz you would loose a lot of detail. bottom line, increase the interp samples and consider using a smaller irmap resolution to save time if you dont loose detail while doing it

[alfienoakes]

Cheers Brian,

 

I did notice that as I decreased the IR quality, I did loose more and more of the "splotches".. but as you say, I loose detail in my map / render (obviously).

 

I will have a play with those settings this pm, and see what I can happily settle on.. I did have my interp samps at 20, still did it. I only noticed it on this large floor plan.. I do quite a few interiors and I live by those settings usually. This is the first big plan I have done for a while..

 

I can change to QMC, which is fine for this type of thing. May be a better way to go for this excercise; find a better combo of first and second bounce..!