Pixel Filters

[Oshyan]

And finally...

- Oshyan

[reck]

This is what i'm talking about. Some nice images here to compare the different filters.

Oshyan, I notice that will a couple of the filters with bloom turned off the sunlight on the water, the reflections, have black lines round the highlights. I'm talking here about the Catmull-Rom and Mitchell-Netravali filters.

Mohawk, the filters don't seem to be having much affect on your test images, presumably because of the reason Matt mentioned.

[Mohawk20]

Mohawk, the filters don't seem to be having much affect on your test images, presumably because of the reason Matt mentioned.

That's why I'm running the same test with Bloom on.
Still you could clearly see Cubic B-Spline did give better results than the others..

[dandelO]

I think cubic B-spline is really too soft to use for a general scene. It works well on your high contrast images above because it blurs so much.
In general I'd only use this for distance shots of background scenery to be postworked in afterwards, a kind of fake DOF effect could be achieved. Never know though, I might find another use for it at some point...

[Matt]

Oshyan, I notice that will a couple of the filters with bloom turned off the sunlight on the water, the reflections, have black lines round the highlights. I'm talking here about the Catmull-Rom and Mitchell-Netravali filters.

The catmull-rom and mitchell-netravali filters have "negative lobes" which have a slight sharpening effect. Unfortunately when you're sharpening high dynamic range images you have this problem of very bright pixels having very dark edges. When anti-aliasing bloom is on, Terragen changes the filter for bright pixels, avoiding this problem.

Matt

[reck]

Ah I did wonder if it was because of negative lobes  . With those sort of images you would be using the aa bloom anyway so it doesn't really matter.

[rcallicotte]

Planetside, thanks for this information.  It's a great addition to TG2 and nice to know how it works.

[Mohawk20]

I just finished the Bloom batch. Not that I can see much difference, but the times might still be interesting...

Box                          - 0:52:15
Tent                        - 0:52:05
Narrow Cubic             - 0:53:58
Cubic B-Spline           - 0:53:41
Mitchell-Netravali       - 0:54:54
Catmull-Rom              - 0:53:51

So overall the fastest time is Box without Bloom at 0:46:32 against the longest Mitchell-Netravali with Bloom at 0:54:54
So on almost an hour render time, the difference is only about 8 minutes... I can live with that.

[Matt]

You're gonna hate me for doing this again...     but I think you mixed one of the non-bloom images in there. Sorry!

[Mohawk20]

Fixed


What should I do without you Matt? 

[Mohawk20]

I'm currently rendering an old scene with high luminosity (lightning strike) with Bloom effect.
I enabled 'supersample prepass', and I noticed that the bloom effect is already visible in the GI prepass.

[dandelO]

I noticed this when I was playing around with luminosity on the moon today. Cool, eh?

[Mohawk20]

Matt, do you remember saying this?:

This is THE best news I heard all week, finally a bloom option, so no more PhotoShop needed!
This raises one question though: Will this also work outside the atmo, in orbit shots? And will the bloom expand if the luminosity value is increased?

You may still want to apply more effective bloom or glow effects in Photoshop. The anti-aliasing bloom is basically just the "first line of defence" against aliasing of very bright pixels, in case no other post processing is done. In a future version we would like to add more controllable post-processing filters, but we don't want to do that until we have a system for editing them interactively on finished renders.

It only has a maximum radius of 5 pixels, and it only add just enough bloom to avoid obvious stair-stepping (jaggies) when pixels are too bright to be anti-aliased using normal techniques. The bloom does expand depending on the brightness of the pixels, but only up to 5 pixels for the very brightest objects such as the sun. It works on any pixels, whether inside or outside an atmosphere.

Matt

(Or should that be "last line of defence"? Maybe I should quit with the analogies...)

I'll prove you wrong!
You just made a great leap forward with this bloom.

The first image below is the original render with an older version of TG2.
The second image is the old exr output tonemapped, and brightened, blurred and set to 'brighten' the layer below it, which was the one without filters.

The last image is the pure bmp output of the latest version, with AA Bloom at Narrow Cubic, and Microvertex and Detail Jittering.

Just look at the improvements there!!!

[lonewolf]

That last one rocks! Even the water looks incredible.
Such a vast difference, and may I say, a slight increase in lightning detail compared to modified exr.

Iain

P.S. You do however need more atmo samples now though. 

[freelancah]

Wow that last one is just marvelous! I haven't had time to test any of these yet but looks very usefull