Quote:
Originally Posted by daveb867
ok in the image i posted i had the settings as described, i then made one change and that was putting the bitmap in the haze slot, i sat the haze value to 1 and the output level on the bitmap to 10, the bitmap was only just visible but it was also not projecting the true colours it did when viewed in a normal windows picture viewer????
|
Of course not; the whole point of the "haze" method is to simply use some *picture* of clouds to drive the haze. The only thing used is the shape of the clouds (derived from the brightness levels of your photo - you may need to play with contrast in some cases). The colors come from the physical sky simulation that uses different haze values for different directions in the sky, hence generating a "faux claud" result.
It's not true volumetrics, of course, but it's pretty nice because it follows the color over time-of-day, and gives you the visible sun disk for free.
Quote:
Originally Posted by daveb867
i then tried with a skydome and just a mrsun, everything works but i had to select unitless on the photgraphic exposure and up the value of that otherwise the scene rendered black,
|
I never said to use
just the mr sun. You should still use the mr sun and mr sky
lights, only you replace the environment shader with your sky image. So only the "visible" component of your sky is swapped out for your photograph.
Quote:
Originally Posted by daveb867
and also the mrsun was having no effect even tho i had used ray switchers on the mental ray material etc,
|
Why would you use ray switchers in this case!?!
You have two options with a "sky background photo"
a) Keep using the mr Sky as lightsource
OR
b) Use the "Skylight" as sky lightsource, set to "Use scene environment" mode, multipleir 1.0
In
either case you must make sure the physical intensity of your "background photo" matches that of a sky, which you by turning up your sky bitmap's "Ouput Level" - or - as you tried - by playing with the "physical scale".
My blog is shock-full of explanations on this topic.
Quote:
Originally Posted by daveb867
with me selecting unitless on the exposure control would i then need to up the intensity of the mrsun to get it to have an impact on the scene?
|
Unitless/Physical mode only impacts "non physical" things (in a practical sense), i.e. whatever this is set to, doesn't impact the suns contribution, because the sun has a fixed physical interpretation at all times, and the exposure control treats those physical values with the physical exposures at all times. The unitless/physical switch is for any non-physical properties, like non-photometric lights, and, also, including your "background image".
/Z