OTOY Forums

Proupin wrote:About the overbright areas getting aliased edges, are you working on a solution?

This is very similar to an annoying (very annoying ) problem for VRay, with sub-pixel mapping OFF.

I was going to point out that; Vray does have a solution for this, even if it means losing ranges beyond 255. The sub-pixel option you mention, caps all subpixels that go beyond 255, so the resulting pixel does not outshine neighbours.

Also, with the introduction of glow/glare, overbright areas get some glow that does spill to neighbour pixels to cover up this jagginess... when it was introduced by Chaosgroup they pointed out glow could be used to address this.

Grabriele, the problem lies with sub-pixels being out of range, and creates such a contrast with neighbouring pixels there's no filter size that can smooth that (without smudging the whole image that is - see edit) The only realistic solution is to be very careful on not using too powerful emmiters that are visible from camera/reflections... if the scene allows. If you HAVE to have such powerful emmitters and they are in the shot, you're out of luck.

edit:

This is a little test of what happens in overbright areas even if you raise the filtering to 4. Results: completely blurred render, overbright pixels get scattered by filtering.

ok now I understand what you mean, antialiasing doesn't work on overexposed objects (mesh emitters)

Probably a clamp tool could help, I always used it in vray + subpixel mapping.

I know a little bit VRay ehehe )))
Sub-pixel mapping in the first version of VRay was hide and, by default, ON. Clamp was exposed.
But, after the 1.46 (or 1.47) Vlado exposed this parameters.
With sub-pixel OFF, we have a better rendering, more realistic highlight, but the rendering time, sometimes (in the interior), is x5!!!
So, if you had a rendering in 3 hours, now, with sub-pixel off, you can easily have a 15-20 hours rendering (BF+LC) Crazy!
I fight every day with Sub-pixel and noise in VRay. But, with our little renderfarm, is not possible turn on Sub-pixel mapping.
But this is not enough, sometimes. If you have bright object or hight light contrast shader, you have equally some artifacts, like jagged edges.
And this is a big problem! So, I must clamp output. Sometime 4-5 is enough, sometimes not.
But this is for a producer render
If we talk about VRay-RT we have two different solution CPU and GPU. In the last version, Vlado, for solve this boring and very annoying problem,
only in the GPU version added a "filter" that "blurred" the final output.
But with strong highlight, the new filter (no option for this filter now. It's on by default and hide) this not solve the jagged edges.
My friend doesn't have this problem with Arion...
In the RT engine, you cannot clamp the output, or you'll lose the HDR.

The look like a photo.. very nice

Hi Ceco,

without your guide I never learnt Vray. Chaos has to thank you.
Recently Chaos and Vlado is getting nervous because we found bugs and we post them.
They don't listen their customers. I posted hundreds of Vray rt bugs

this is not the place to post vray bugs obviously.
I would like to use Octane for Max for all my renders but today I can't.
We need several tools to do everything.

Yesterdey I used Vray rt to render an interior with a lot of glass panels illuminated by hundreds of ies lights.
In Octane you can't because it doesn't have an architectural specular mat. You can't simulate transparent thin walls with glossy mats because they are fake and you lost refractions on borders.
Also the sun doesn't shine through the glass.
Regarding the ies, try to point 100 lights rotating that tiny diamond. Octane needs directional lights with target point.

Regards

VRay Producer is old (2001) and strong renderer. VRay-RT is young and we would like to see all the VRay Producer tools already in the RT version =)
Same for Octane vs Octane4Max. We must wait, with patience

gabrielefx wrote: In Octane you can't because it doesn't have an architectural specular mat.
Regards

Did you try to use glossy material with 100% reflection and falloff in opacity?

gabrielefx wrote: You can't simulate transparent thin walls with glossy mats because they are fake and you lost refractions on borders
Regards

What do you mean?

gabrielefx wrote: Regarding the ies, try to point 100 lights rotating that tiny diamond. Octane needs directional lights with target point.
Regards

Does it make sense?
It is without a target point. At least you can see the direction.

Sample of fake glass