So, I’ve been all over the radar with rendering software for the last 5 years, but have been consistently coming back to vray lately for most of my animation work and large mass rendering projects for it’s flexibility.
The major hang up for me now is those nasty jaggies where highlights are overblown. I’ve tried all sorts of VFB blooms and post glows, but it just never looks right. This is where I have to fall back on other rendering engines for still work.
To be honest i don’t think any renderer “just works” ( i work with several too ), and that’s why it’s important to have some settings to play around to solve issues like this.
Talking about Max Ray Intensity, I still don’t understand the value of this setting … what does it correspond to ? how should I know if the default value of 20 is enough or too high ? how should we know how to tweak this value ? increasing it ? decreasing it ?
Thanks.
The Max Ray Intensity will cut the actual value of the secondary rays to the one you have set in order to suppress very bright rays which might cause such issues, just like the Clamp output and Sub-pixel mapping options. The drawback of this will be that the overall brightness of the scene might be decreased.
Low Max Ray Intensity values will ease the antialiasing calculation respectively better render times but it might decrease the overall brightness. The best way to know what value to use will be to test it. Check which value manages to decrease the overbright pixels and still keeps a good overall brightness.
ok, understood - thanks for your answer. However, that doesn’t about the unit of this setting … is that a percentage ? sorry to insist, but I don’t like not understanding something
Its the intensity of the pixel/ray. You can check the pixels intensity in the VFB. In example if you set a light Multiplier to 30 and you render that light you will get intensity value of 30 for the pixels in the light itself and if you set Max ray intensity to 15 the GI, Reflection and Refraction rays generated from that light will be cut to 15. So no mater how high you set your light multiplier, Max Ray Intensity will cut its GI, Reflection and Refraction rays to 15. I hope this helps.
Thanks for these additional informations, that definitely helps !
A last question, to be sure I understand: now if my lights intensity is, let’s say, 10. Setting Max Ray Intensity to 20 won’t have any impact, right ? since the “cutting” value is above the initial value … so I should set Max Ray Intensity to 5 for example to get it working, no ?
Again, please excuse my insistance about understanding … we regularly face the jaggies problem on high intensity reflections / hightlights, and I’d really like to know how to efficiently get rid of this.
The only thing that changes for me when I reduce the value dramatically is the scene gets darker, but the jagged reflection remains. I tried reducing the amount to half of the light that is causing the problems, but nothing changes.
I did some quick tests here. I guess the jaggies are just the result from trying to fit the bright pixels of the hightlight next to the darker pixels where the highlight dims. Using larger resolution will produce better result because there will be more pixels inbetween for interpolation. Another solution is to change the BRDF type in the material setting and see what comes out. Here’s how it looks in my tests.
They say Ward is best for metal surfaces and the results confirm it in this case. Was this helpful for you?
now if my lights intensity is, let’s say, 10. Setting Max Ray Intensity to 20 won’t have any impact, right ?
that is correct
but the jagged reflection remains
if the Max ray intensity doesn’t help you can use use Clamp output and sub-pixel mapping with clamp value of 4/5 in example. On another hand if you want to fully preserve the dynamic range you can use lens effects (this is how bright areas are smoothed in real photography). Also another option will be to check which light generates this bright highlight, disable it s reflections, create a second identical light which affects only the reflections and decrease its intensity.
