I really should just give up. But I thought, no, I have been too hard on the particle system. After all, I have this great landscape generated from the ANT landscape script. I even created a nice node based texture to go on the landscape. http://blenderartists.org/forum/showthread.php?t=156948&highlight=ant+landscape
Then I thought wow, this needs some trees. So I selected a bunch of vertices and created a group for my trees, but that was not good enough, a forest has many trees. So I wrote a sub-divide vertex group script to create multiple subgroups for each tree type. http://blenderartists.org/forum/showthread.php?t=158671
Now when I finally have all the parts, and I think, this is it, it is going to work! But no, Blender let’s me down again. Pie in my face boing (ha - ha every one laughs) they did it to me again. I don’t know why I try.
It looks like Blender can not cast shadows onto an object that is using a node based material!
What a let down, all that time wasted and I still can’t realize my concept using Blender…
The image on the left shows what happens when you try to cast a shadow through an alpha based image map onto a surface that is using a node based material. Yes, I have TraShadow turned on for the node based material and all it’s sub materials (you can examine the material from the landscape link above). The image on the right shows what happens when you use a non-node based material.
I did some quick tests and node materials can recieve transparent shadows, but to get transparent shadowing on any material other than the base the material casting the shadow has to have pixels of 100 percent transparency, in other words the node materials that is not the base material will not show up unless the shadow is 100 percent transparent, so say with a wood texture casting the shadow and a mesh with a blue material layed ontop of a red one only the red will show in the shadowed parts and the blue will only show if it’s 100 percent transparent. A shame really because a professional would think the devs. took a quickie incomplete lazier way to do this and put in a simple transparency test rather than a real alpha test.
@CD: Thanks for taking a look at the problem, so you are hinting there is a solution? I believe my texture files have a true 100% alpha where required. What can I do to make this work? I hate to lose all the time I have invested in this concept. I really want a wooded mountain side.
What I did was search out for all the material nodes in the node tree and set TranShadow every time I clicked on one, but that doesn’t fix the problem with materials layered on top not showing in shadowed areas.
I can’t see how hard this would be to fix, and some node rendering bugs have been fixed since 2.48 like node materials being unable to even cast transparent shadows.
