View Full Version : No AA with self illuminated surface + perspective camera

01-24-2011, 06:03 AM
Is it correct that self illuminated surfaces rendered by the perspective camera do not anti-alias at all?

Don't know what I'm doing wrong.

01-24-2011, 10:47 AM
How bright are the self illuminated surfaces? Part of the problem with antialiasing is it interpolates nearest neighbours.. so say you have 1 point which is 50% bright, and it's neighbour is 550% bright, then the interpolated pixel will appear 300% bright, which on a regular monitor will appear just as 'white' as the luminous one.

There's 2 solutions to this.

1) use the setting 'limit dynamic range' in the render globals. This will clamp your brights, so AA will work properly.

2) the more complex but better solution is to tone map the render in a 3rd party app. If you save out a EXR or HDR then you will be able to open the image up, and tone map it, accessing that 'invisible' data, and allowing you to see it properly by modifying the visible pixel display curves. Sadly it's a complex subject to explain easily!

The downside of using the 'limit dynamic range' function is if you do want to work in a floating point environment, you have thrown away any pixel data above standard 100% brightness, which can affect things like DOF, BOKEH and motion blur.

01-24-2011, 02:38 PM
Ah, I never thought of this. Clever.
I expected this effect would be slighty softer when rendering with multiple AA.

Thanks, IŽll try to adjust the dynamic range tomorrow morning.
It seems to be the first time in my life I really going to need this feature.

01-24-2011, 03:08 PM
you can always render with limited region that surface's area with double resolution and then resize it to half and compose...not very pretty but works

01-24-2011, 04:57 PM
there's another way, you can use HDR filters on the image, which basically blurs bright bits to smooth them out, there's a couple of them to choose from in the render globals

I personally don't really like results though