Arcon
11-26-2005, 09:38 PM
i've got an outdoor scene and i'm rendering a reflection pass which is basically just the glass objects, with everything else set to matte opacity zero for the composite.
the problem is whenever an object that has transparency comes between the glass and the camera, you can see the portion of the object which should be transparent as it passes over the glass, it looks like a semi-transparent 'dark shape', for example some paintFX trees which i converted to polys, you can see the areas of the leaves which should be transparent (i've tested by dumping a simple lambert on the leaves to make sure it wasn't their shader, and i got the same problem as soon as i added transparency to the lambert). i'm pretty sure the problem is not just paintFX polys, i've got poly planes in the scene with transparency maps and same issue.
i found out what causes this problem but i don't know why, nor do i know a good solution :). basically i can only see the problem when the glass is assigned anything with a specular component (phong, blinn etc). a dgs shader works but that's not an option, too much rendertime.
there is no radiosity in the scene, and i've tested it without shadows, same result. there is some light linking but i don't see how that shold adversly affect things. i've tried maxing out global ray depth levels, reflection levels etc.
it renders fine in maya software, only MR has the problem. i can't composite passes from the two renderers though so i really need a solution to this. :/
the problem is whenever an object that has transparency comes between the glass and the camera, you can see the portion of the object which should be transparent as it passes over the glass, it looks like a semi-transparent 'dark shape', for example some paintFX trees which i converted to polys, you can see the areas of the leaves which should be transparent (i've tested by dumping a simple lambert on the leaves to make sure it wasn't their shader, and i got the same problem as soon as i added transparency to the lambert). i'm pretty sure the problem is not just paintFX polys, i've got poly planes in the scene with transparency maps and same issue.
i found out what causes this problem but i don't know why, nor do i know a good solution :). basically i can only see the problem when the glass is assigned anything with a specular component (phong, blinn etc). a dgs shader works but that's not an option, too much rendertime.
there is no radiosity in the scene, and i've tested it without shadows, same result. there is some light linking but i don't see how that shold adversly affect things. i've tried maxing out global ray depth levels, reflection levels etc.
it renders fine in maya software, only MR has the problem. i can't composite passes from the two renderers though so i really need a solution to this. :/