shadow from the alpha texture

i was trying to get the shadow from the plane that applied with alpha texture (chess like texture)

using this texture

and i put a red spotlight at the back of the plane (and i thought i would get some shadow generated by the chess (white part). but … :frowning: :frowning:

i use the following method to set the texture on that plane
{from: jedicinema}
-Under Map To tab, map the image to Alpha (or Col & Alpha)
-Under the Material tab, turn A. to 0.0
-Under the Mirror Transp tab, turn on ZTransp

so, any idea? maybe i miss out something? :confused:

Did you try ray transp? and ray on on the lamps panels, too.


If you want to see shadows on the floor, you will have to turn on TraShadow in the shaders panel for the floor material.

Best of Luck!

hi pikseli & obi,
after i turn on the TraShadow, it works!

big thanks to obi.

I guess I’m pretty stupid because it doesn’t work correctly when I try to do this tutorial:
I’ve put on TraShadow, so that can’t be the problem.

I’m using Blender 2.42a; does this version maybe needs other settings or is there maybe a little bug?

Hope someone can help me,


gallardo, it works fine in Blender 2.42a. Make sure you are following the instructions on that page exactly - especially the two important settings right at the bottom of the page.

Okay, so I’m really stupid. :wink:
But still, it’s not working (even after remaking it and following the tut exact).

I attached a printscreen of the settings and the result.


btw: thnx rawpigeon for the fast reaction


I tried this thing again and again… and finally I found the solution. :smiley:
I type here the solution because I think it will be usefull for others who have the same kind of ‘problems’.

I only put the TraShadow on for the plane with the leave.
You have to put TraShadow on for the object on which the shadow is ‘projected’. If you make the two planes in one object, it will work fine too!

Does anyone know the reason for this?

Thnx again for the help rawpigeon,


Glad to see you found the problem! From your screenshot it didn’t look like your two planes were two parts of the same object - in fact, how did you texture it? You’ve only used 1 material - did you use a uv map? I thought the most likely problem was that you had TraShadow enabled on the leaf object instead of the shadow-catching grey plane. Could have been a weird glitch!

You are right again rawpigeon. While testing it yesterday it suddenly worked. I thought it had to do with the objects but instead it was a fault I made with TraShadow as I explain in my previous post (which of course, I edited :wink: ).

Thanks again (and srry for my bad english),

Glad you figured it out - it’s not terribly intuitive, is it? Lots of people have that problem. If it was turned on by default it would solve this problem, but then slow down rendering on all the other materials. I guess the idea is it’s better to learn how things work and do it properly.

As a memory hint, I’m pretty sure the tool-tip for TraShad says that it enables the material to RECEIVE Transparent Shadows.

I guess practising is the best way to learn to work in blender.
When making faults, searching for solutions (and hopefully finding them), you really learn understanding all the functions and possibilities.

remember: practise makes perfect… or in my case at least better! :wink:

ciao & thnx again for the help,