Hi!
In my project I need a warm effect light. Kind of like the one you get from Ikea (pics). I played around a little with different effects for this specific paper effect. I guess I got it fairly good now for the begining.
I also set up lights on the inside of the lamp.
The only thing now is to get this shine-thru-effect. = On darker arreas less transparency and on lighter areas more.
How can I achieve this?
LeFish
Place a lamp inside the lamp shade. In the material settings, enable ZTransp. Below the RGB colors, there is a slider with an A, which is short for Alpha. It is now set on 1.0. Slide that baby left and your material will get a lit from the inside. Too much sliding and is disappears, like quality from your ikea product. Too little, and it will not shine through, like a burned out bulb or electrical short in your newly purchased Ikea product.
Thanks alot. Didn’t think it was that easy!
Hi!
I dont really know what I do wrong, but I followed your description and my lamp does not get lit from the inside… There is light outside reflected by the walls now, but this nice indirect lighting-like effect is still missing…
hope someone knows what i am doing wrong…
LeFIsh
lighting is NOT that easy. There are people in CG whose entire JOB is to light. I sometimes spend a whole DAY just lighting a set. You wont get it with an hour’s worth of work. You have to play with it. There are good lighting tutorials out there. read the wiki on lighting and lighting rigs. there are books in the library and on Amazon. You may have to use multiple lights of different types and intensities to get the look you want. This picture has a tube of alpha .6, with two lights, a lamp and a spot, inside of it, and the scene is illuminated with another lamp. Learn, play, experiment, succeed. Good Luck!
It may just not have been rendered, make sure the red highlighted button is pressed down.
Wait, there’s a button in Draw Extra that has to do with how stuff renders in any way? That’s kinda screwed up, since everything else there is about showing you extra stuff or changing how it displayes WHILE EDITING . . . O_O.
no, that is for on-screen. but the ZTrans button in the Materials panel does have to be on if alpha is anything less than 1.
No no, ignore leadgolem, he’s talking through the back of his neck. Actually, I’m using fire-fox and the dictionary thought I spelled ‘leadgolem’ wrong. The first correction that it offered was ‘misleading’. How apt.
Anyway, you can control translucency with the ‘translu’ slide in the shader tab, and if you want more control, you can control the amount of translucency with a texture map.
so I’d probably have to map a texture, with wich I want to control the amount of transluency , to the alpha channel, right?!
do I have to have ray tracing on for transparency? are there any differences in this term in between blenderinternal and yafray (the one I wish to use for my finals)
LeFish
No, you’d have to map it to the translucency channel. Anyway, be warned, blender’s translucency is a cheap hack, it basically just lights backfaces. 
I’m not familiar with yafray, on the other hand, so I can’t help you there.
LeFish,
There’s a few different aspects of the ‘ikea’ effect that you may be trying to capture. One aspect is capturing the translucency of the paper, which all of the comments so far have been about. The other effect is the diffusion. The quality of light through paper is very soft and non-directional and (unless I’m mistaken) even if you use the technique here perfectly, if you’re just using a single lamp inside of your lantern, you still get a very hard light that doesn’t give that paper lantern effect.
This seems to me to be a textbook case for using radiosity, which gives a softer more natural light and allows you to use translucent materials to diffuse light. If you don’t want to use it or can’t affort the extra render time, I would point to what RogerWickes mentioned: “You may have to use multiple lights of different types and intensities to get the look you want”. I’ll expand on that a little bit further. The diffuse light effect happens when light comes from a spread out area rather than just one point. One way to get that effect is to use multiple dimmer lights near each other, rather than one brighter point light. You might explore using dupliverted light sources on a slightly scaled copy of your lamp mesh. You might also explore using spotlights with the new irregular shadow buffer feature, show here:
http://www.blender.org/development/release-logs/blender-243/irregular-shadow-buffer/
Information on lighting in Blender can be found in the lighting section of this page:
http://wiki.blender.org/index.php/Manual
There are a lot of different ways to light a scene. I hope that my thoughgs here might lead you to some new ideas.