hi guys,
can anyone tell me how to make an object emit(colored) light and how to render it?
i’ve tried the emit value and rendered with AO, but it only makes the material brighter.
i want to put some glowing lava in my picture and the sourrounding area should be lit by the red/orange/yellow texture on the lava.
yafray would be the last resort, but i don’t want to readjust all my lights and colors in the scene
Use radiosity.
is that only possible with radiosity? my scene is currently set up for an AO render, changing the render would mean i have to adjust the materials and lights again and that takes ages with that render times…
atm i’m trying to fake that effekt a bit with an transparent halo mesh around the lava mesh… maybe that looks acceptable, i’ll post the pic then
Radiosity is not the best way to do such things as it subdivides the meshes and can take forever.
You could use arealights with a really high square size to simulate the glow from the lava.
nodes and area lamps. nodes for the glow (lava always looks better with glow) area lamps for the light.
now ive used nodes for some glow and an area light, the pic is pretty low res but the effect is visible.
i like the result, but there is still a shadow under the lava, thats not so realistic.
a copy of the lava as a mesh of halos does a stronger effect btw… but i think i will stick to this techique now.
Use lamps to fake it, paint it on, or use halos.
The shadow can be removed quickly by turning shadows off. A 3D software platform I worked with once (don’t remember which, possibly several different ones) had shadow color as a variable. Does Blender do that?
damn im so stupid 
just had to disable the casting of shadow for that lava material…
a shadow color variable does not exist in blender(as far as i know), but maybe nodes can do the job here. but in my scene its not required now.
i’ll post the next result after the render is finished, stay tuned
yes, the 2.43 has a separate shadow render, so you can color adjust just the shadow using nodes.
i’ve figured the technique out. halos, glow, nodes, area lights… they all do the job, halos and are lights give the most realistic effect. but nodes fake it very good, and save render time. i wont post the final result of the picture here because i already postprocessed the last “with shadow” render, didn’t have the patience to render again
u can see the final result here. thanks for the help everyone!
Did that sand(?) material have some sort of reflection value? Is it traced? I want to simulate a room with radiosity minus the mesh killing messiness of it all. I have found the lamps to give an unrealistic bounce effect though. Cute scene BTW
yes its supposed to be sand
render is an AO with 6 samples, sky texture(which is a white blue sky) , 0.4 energy.
OSA is 5
the sand is slight yellow (F3F7BA), shader is oren-nayar with about 0.5 ref and nearly max roughness. spec is blinn with about 0.2 spec, 19 hard, 2.5 refr.
i’ve never managed to make a good (well maybe it looked good, but not realistic) render with radiosity in blender. ambient occlusion with an area light and/or skytexture behind a window is IMHO easier and better.
i would rather try yafray, sunflow or kerkythea(check out the GI/indoor/outdoor tut)http://www.softlab.ntua.gr/~jpanta/Graphics/Kerkythea/) before playing around with radiosity
regards
tick