I made a small video in blender: http://www.vimeo.com/8481706
But, there was a problem, when I made it: a can’t use the render passes to take the objects to background, because if I mix the passes, the shadows (and AO) on the floor are disappear, and the alpha channel, too.
I want to use passes, because I easily set the lights in the scene. The “only shadow” material isn’t so good, because If I switch on the AO, the shadow is disappear. I tried to use the render layers but it wasn’t so good.
Could somebody help me? How can I do it with passes?
Please post the Blend file- and I’ll see if I can correct it- it might be better than explaining it- but I will after I correct it… Short answer- the alpha channel controls the shadow- not necessarily the AO or shadow pass when using it like you have- this means working with your plane and boosting the “Amb” setting under shaders to tweak how much the ground recieves. when recompositing it will take down the amount of shadows- so sometimes it has to be tweaked from the material “amb” setting. It can be done with nodes also, but its better to see the file first before continuing…
Thank you the fast reply! Here is the blend file of my tries. The mixing of diffuses are OK, but the shadows aren’t so good.
Here is the animation scene if you want it, but it isn’t good to show the compositing techniques:D:http://www.pasteall.org/blend/1535
OK,
I think I see what you were trying to do- and I think it was the right path. You boosted the AO then tuned the shadow by adjusting the alpha of the ground plane.
A quick fix is to boost the AO to 3, then boost the ground material Amb (Shaders Tab) to 1.0, that will give you the deeper shadow and then yeah- tune it by adjusting the alpha of the ground plane (Or a balance between those three methods). If it affects the character use the “Amb” setting to scale back on his texture. Ambient Occlusion does not operate always as expected on approximate and is not part of the shadow calculation pass for lights (Ray tracing).
Your lights may not operate as expected due to the scale being so large, but if you were looking for a deeper shadow as a quick fix- try those tips. A more delicate shadow would have to be a few other methods…
Just keep in mind that when you use the ground plane that way- the alpha controls the shadow length…
One other thing- if you need to tune the shadow color alone, you might need to set the material of the alien to “Only Cast” and just render out a completely different shadow pass…
Thank you!
That is a really good idea, but I think it isn’t the best way. How can I make the same shadows as on the normal materials. Or is it impossible?
I will try some way of compositing, hopefully something will be good.
Well actually- it may be the best way because of your scene- ya see- the lights are affected by scale- which means that won’t operate properly because the scale is a little off. Also, you’re only using AO- which means it will not cast a ray shadow which the pass is taken from the lights- so you’re going to have to pull the shadow from the AO pass and not from the typical shadow pass- so because the scene is set that way (kinda of a little circle- one thing affects another)- you might have to sompensate with other CG tricks to do the job- try changing your scale- but yeah there is a better way- but it involves kinda re-doing the project- or atleast altering some elements- which I guess is good…
Maybe theres a better way to jumpstart the shadws the way you want it- but I guess someone else will have to take a stab at it.