Hi. I’ve run into a bit of a problem that I just can’t find the answer to elsewhere so I thought I’d ask.
I’m trying to render a 2D image by plastering it onto a plane as a texture. The image itself isn’t square so I made use of the ZTransp button (only took me two hours to find, that one) so it actually appears to be an arbitrary shape. So far so good.
The problem comes when I try to render a shadow. I know how you basically set up shadow rendering, but what I’m finding is that the shadow cast by my alpha-image carrying plane comes out plane-shaped (ie square) rather than image-shaped. If anyone knows how to get the shadow rendering accurate in this situation I’d love to know – I can’t face sifting through page upon page of HTML in the hopes of stumbling across the answer any more!
best bet… slap ya texture on a new plane thats the right shape for the image, then find the sizes in material mapping (input)… if you know the dimentions of your image, a little bit of maths may come in usefull…
good luck
p.s.
if you really want to render shadows of the alpha, your only real option is to modify the textures to look like shadows, then render from the lamps perspective, use that image with a duplicate spot shadow lamp that has its clipping set to only effect the area where the shadows area case (also works well for rendering shadows of halos)
… or maybe trans shadow raytracing can do it too… been to busy to play with rays properly sofar
It can, as it turns out, but only if a few other things have been set up properly (see below.)
That’s it! I’d already found the TraSha button but it wasn’t making a bit of difference… however, following the ray settings in dgebel’s post AND making sure that the light itself was set to ray tracing rather than shadow buffering fixed things right up.
Many thanks guys - that was driving me up the wall!
