How to avoid specular jaggies with clamping unchecked

[stevesideas]

Hi Guys,

Im currently rendering out various interior shots of an aircraft cabin. I have read that you gain more control over a 32bit float image so I made sure that clamping was not checked. So now I have the problem of jaggies on all the edges of objects where the sun is very bright.

How do other users of vray and 32bit float tackle this problem ?

Also, apart from exposure, what benefits do I have for using 32bit float ? Assuming the exposure for the image is looking good and wont be changed in post, is there any reason to use 32bit float ?

Cheers

[vlado]

In general, you solve this with a slight bloom or glare effect in post.

You can also sort of simulate this using the Blend AA filter with a relatively large radius, but of course the blurring will also bring down the HDR range.

Best regards,
Vlado

[stevesideas]

ok cheers for that. I'll probably do the bloom in post.

[Sascha Selent]

...the problem of jaggies on all the edges of objects where the sun is very bright.

Normally I exclude bright light-sources from affecting specular and / or reflection. This reduces jaggies especially in very small geometry-details. This is not possible with a sunlight...

...but maybe you make the sun invisible?

I also use a shellac-material to override the VRay-material-speculars.

Sascha

[duke2]

Normally I exclude bright light-sources from affecting specular and / or reflection. This reduces jaggies especially in very small geometry-details. This is not possible with a sunlight...

...but maybe you make the sun invisible?

I also use a shellac-material to override the VRay-material-speculars.

Sascha

Good God that must hit your rendertimes! From my limited tests, shellac resulted in exponentially higher times.

Vlado is right though, the jaggy speculars are because they're such high values. Spit out a VRaySpecular element, do a gaussian blur of between 0.5-4.0 and put it on the top of your rendering in Screen or Linear Burn mode.

[Sascha Selent]

Good God that must hit your rendertimes!

Hm, yes, it renders longer, but not that crazy.

But this is something for the wishlist: standard-speculars with multi-layer-control for the VRay-material. I do quite often have to exclude lights from specular/reflection because of too heavy speculars.

[stevesideas]

I dont understand why it would be that hard to create a specular bloom option that was defined by the light intensity on the objects..with a bit of control too obviously

[vlado]

I dont understand why it would be that hard to create a specular bloom option that was defined by the light intensity on the objects..with a bit of control too obviously

You can already do that with the Lens Effect render effect for 3ds Max, quite easily and with lots of control.

Best regards,
Vlado

[vlado]

I do quite often have to exclude lights from specular/reflection because of too heavy speculars.

If you need to do this often, then something is wrong either with your materials or your lights set up; it would be much better to set up everything properly than to constantly have to resort to workarounds.

Best regards,
Vlado

[stevesideas]

You can already do that with the Lens Effect render effect for 3ds Max, quite easily and with lots of control.

Best regards,
Vlado

I tried using this method in vfb, but it doesnt seem to work. Thats really where I would like it. Also, do the max glow effects work with 32 bit images ?

[mike_kennedy]

Better off doing that in post, think I will try that pass, rarely run into this but might be a nice look to add.

[vlado]

I tried using this method in vfb, but it doesnt seem to work. Thats really where I would like it. Also, do the max glow effects work with 32 bit images ?

Hm, not really, for both of these. But, we are working on it (not with the 3ds Max Lens Effects of course)

Best regards,
Vlado

[HAWF]

Hm, not really, for both of these. But, we are working on it (not with the 3ds Max Lens Effects of course)

Best regards,
Vlado

WOW! Will we see it on SP3?

[vlado]

Not for SP3, most likely, as it requires substantial changes to the VFB, which are not appropriate for a service pack.

Best regards,
Vlado

[stevesideas]

I do like these little hints that Vlado gives away occasionally