Shadow of Alpha Map

[shushens]

Hello Everyone!

I am making this scene in which I want to fake sunlight through tree-leaves on a house and the yard. So I have prepared an alpha map of a tree, and I want light to come through only the dark spots, i.e. gaps between the leaves. I am a newbie and not sure how to arrange an opacity mask ( or maybe it is called something else) so that light fully passes through the dark regions and gets completely blocked by the white regions.

Please tell me how I can achieve that effect.

[shushens]

Okay! done it

http://img265.imageshack.us/img265/9780/newpicturerd0.jpg

Never mind :)

[jamal]

Hi shushens,

You can also do this by attaching slide projector shader to your spotlight.

Select the spot (the light itself, not the root or the interest), open the render tree, and choose Nodes > Light > More from the menu. You'll get a browser listing all of the light shaders. Choose Slide_projector. Plug it into the Color port on the soft_light shader.

Hope that helps,

J

[franky]

you might wanna have a look at the sprite shader (under illumination).
it cuts out something with a mask and doesnt involve more than one ray.
the problem with transparency is, that when you have severa of these alpha mapped transparencies behind each other, you have to raise the ray depth to insane counts to go through them all.