"Mike Miller" <mil### [at] gmailcom> wrote:
> I've run into a problem with the transparent portion of the png when turning on fog.


https://wiki.povray.org/content/Reference:Fog

I think that you're going to have a hard time with the fog since it's purely
distance based.

Also, there's no really good way to make a "cutout" from the transparent image.

You could do a few things.
Try and make a custom prism from the image with a macro.
Make a heightfield from the sprite and difference away a box, leaving just the
visible portion.

fake the fog using a large upward-curving surface toward the rear of the scene
and pigmented using a distance-based function.

Try a thin wedge with a white pigment and slight filter value that gets higher
toward the rear.  The filter may mimic the fog/media effect and be cheaper.
If you need to speckle it like real media, maybe use a noise pattern to make a
texture with white / clear.

Do a 2-pass render with the plants billboarded over the fogged scene afterward.

That's all I got for now.

- BW

Post a reply to this message