help with volume light....

[hydro]

here is an example of the scene..



my method was putting a direct target as sunlight...with vray shadows on...i made a copy of the light and turned off the shadows..and assign this as my volume light....with a density oh 6...but as u can see...my scene got all foggy inside...that might be becuase of the big light entrance at the end..but still..my purpose is to get the volume fx on the skylights i got on the roof...but as u can see the fx is not accomplished....im going to make a try with a higher density..but maybe im doing something else wrong...may my photon settings or anyhting else...any help will be apreciated

greetz!

[trixian]

well your volume light needs to cast shadows...more specifically shadow map shadows.

[hydro]

i used shadow map but its didnt work either...what might be wrong?

[jedisalf]

why dont you work with 2 passes and then use Photoshop to composite them.

One pass like the image you posted, and the other pass, set all materials do a dark material, so you can only see white or grey the volume of the light.

[trixian]

Make a duplicate of your sun light. Make sure its a direct light and focus its shape along the long slitted opening in the ceiling. Set your shadow map to be abour 1600 in size, and make sure your bias doesn't miss the geometry...(the default value of 1 is a but much in most cases). If this doesn't give you proper volume light, then i dont know what youre doing wrong.
Oh...and make sure your attenuation values are set up correctly, as in far attenuation start starting aproximately at the opening and the end one past the floor. Also I find using the blue attenuation colour in the volume light settings makes for good realistic results....for white-ish light that is.

[hydro]

thnx a lot trixian...its worked!!....

[mohinder]

Can you post the result.Thanks