32bit float alpha

[Filip Kaczorek]

I've been doing a lot of testing with rendering FFX in true 32bit.
Everything seems to work as expected so thanks for this.
I have one idea/suggestion:
is it possible for fume to also store a 32bit float value for the alpha?
ie. A pixel with an alpha equal to 2.0 would be twice as opaque as a pixel with alpha=1.0
Would seem the same during render, but later in post we'd be able to thin out the smoke leveling down the alpha value. Right now the value is being capped at 1 and we can only get a flat semitransparent area of the smoke - would be great if we could restore the transparency variation there.
Is it even possible for FFX and AB for that matter?

[sitnisati]

Hello,

That is not possible as each shader calculates transparency which goes form 1 to 0. Alpha is just an inverse of final transparency.

Regards,
Kresimir Tkalcec

[Filip Kaczorek]

For a single voxel yes, but don't you have to add all the transparencies from all the voxels along the camera ray in the volume to get the final look?
I mean imagine a couple of flames in a single line - each one of them is transparent (not fully opaque) but when you look at them all in one line they create a "solid" flame pixel that could have the alpha = 1. But this 1 was created by some process of accumulating transparencies from all the flames, right? I think even your fallof (visibility and shadow) functions are just based on assigning different weights to the voxels being accumulated - couldn't the result of this accumulation be greater than 1?

[sitnisati]

Thank you for the suggestion, but I'm sorry as that cannot be done.

Regards,
Kresimir Tkalcec

[Filip Kaczorek]

Cool, thanks for listening