rainy day here today so i tried to recreate the geekatplay "tree in medow" image. i was also browsing through cornucopia and saw some nice looking butterflies and thought that should not be difficult to do myself. so after browsing the internet for butterfly images and creating textures out of them in gimp i was able to create image below.

now in the process i found that i have to adjust the scale of all the eco objects/plants until they look right. is there no way of kalibration so that grass is always in the right size compared to trees (and maybe in conjunction with the unit system)? or is there a disadvantage if that would be the case?

and with the butterflies (for placement in air i applied the tutorial with the invisible tube) i created a body plane and two wing planes. the wings i made in gimp in a way that the alpha plane was "invisible" (black) for the outside of the wing and in the wing the orange areas kind of transparent (grey), the rest was opaque (white) and saving it as a TIF-file.

after importing vue recognized the alpha correctly from the tif and after setting the material to one-sided and backlight it look good to me. in the shadow you are able to see the effect of the different transparencies in the wing.

in one test i tried to also activate color transmitted light and expected the shadow to be colored but then the "invisible" turned solid and also made a shadow.

ì guess i am missing something? but what? :)

thanks in advance
chris

Regarding size of stuff:

Yes, very annoying. Different merchants sell their items with different scales. Some are correct, others not. If I'm not mistaken, your grass is from AsileFx, correct? That's one of the grass I always have to correct. The items from Linda Daireaux in C3D are usually right.
When I use an item often, I save a version with the correct size for reuse later.

Regarding color transmited light:

Try driving the "color transmited light" slider with a function. Click on the little lightning that appears left to the slider and link the node to the transparency node. I didn't test this, I'm not sure if it works, maybe you need to do some variations around this, but it's probably the right direction.

Hmmm... no, regarding the color transmitted light, it's not as simple as I wrote. I just made a quick test and my suggestion doesn't work. Let me try some more...

actually it does work!

i just had to make sure it connects as greyscale and not as alpha. i also used a filter to bump up the non black values because before the colors did not show that much ... and there is a artefact line on the right which means i have to adjust the filter or the texture.

now i want to understand the difference between alpha and transparency. here i slapped the rectangular pattern in the alpha of the one wing.

so i am guessing alpha modifies the "colour" (light reflection to observer?)) and transparency the "shape" or density (light transmission?)? but the alpha also affects the colored shadow?!? and where would i need different maps?

and what is the difference idea of connecting nodes via grayscale or alpha?

i just hope my curiosity is killing no cats!

I'm glad my "theory" gave good results. :-)
But I have no deep experience in the rest of your doubts, I'm not the right person to answer this in depth. Others will hopefully step in. :-)

Alpha and transparency are the same thing when it comes to apply a transparency (or is it alpha?...) map. But if you want to apply some colour transmitted light, it has to be done in the transparency channel, and not the alpha channel.
Now alpha is also used for various degrees of opacity in a material layer, or for blending materials (the smooth blending strip you can set in mixed materials is actually an alpha transition between mats.)
In the FE, you have the option to use a texture as either an alpha or greyscale, depending on what part of the material you are editing). Greyscale has to be used, but I wouldn't know why, and neither why choosing alpha instead of greyscale makes  a completly different material.

thanks!

Here is a tutorial I did that incorporates alpha maps.  It is a modeling and animating tut but it also shows the why and how of alpha maps.

Part 1
http://www.geekatplay.com/flvplayer/player.php?pathinfo=garyhexmodelfan1

Part 2

http://www.geekatplay.com/flvplayer/player.php?pathinfo=garyhexmodelfan2

Here's another one

http://www.geekatplay.com/flvplayer/player.php?pathinfo=garyhexmoelsalpha

Hope this helps ya

your tutorials are great ... looking forward to watch these :)