NOT SOLVE> Yafray objects as lightsource ie. flourescent

Hi all,

>> ADDED: I recently added that the problem was solved, but it was an illusion. The shadows where actually not cast from the lightube. Im Still working on a solution to fix this within blender. It seems like it wont be an easy one though. Fiddling with the xml-file seems to work…havnt tested it fully out, but it would be easier to just use yafray directly from within blender.

IM trying to make an emitting OBJECT as LIGHTSOURCE with YAFRAY. The function emit works fine in blenders internal renderer, but the interlan blender quality compared to yafray…do i need to say more?
Its a cylinderchape that i want to emit 360 degrees (not in the X axel = the ends) like an neonlight-tube.
Have fiddeled with various settings in both material and yafray with no resutl. The cylinder dont cast any light or shadows at all.
Ive tested to gather meshes in blenders radiosity, and when i press GO the tube emits nicely (low poly)

>> ADDED, i dont want any spotlights or that cind of lightsourcetricks. Must get the tube to cast realistic light. Have tried rect arealights to put inside the tube. But not acceptable result. As you will se there is a cind of thingy that you can rotate in the X-axis to cast the light (if succesfull) in different angles.


You could try using an hdr image as a texture on the tube. Here is an example.


Forget what I said: I’ve been experimenting.

The emit value for a material does indeed cast light in yafray (when using global illumination), but an emit value of 1.0 isn’t enough. Increase it to about 20.0 and you get similar results to the above picture. To do that:

  • In blender, make sure your yafray path is set to something sensible.
  • Run the render to create an xml file for yafray (you can cancel once the xml file has been created).
  • Open the xml file, find the flourescent light material, and change the emit value to, say, 25
  • Run yafray from the command line to render the xml file.
  • View the tga in gimp or whatever.

That should do it.

Hmm, interesting.

It’s kind of a shame that to get objects emitting light in yafray, you have to manually edit an XML file to do so.

That’s all well and good for a single frame render, but what if this project were an animation? :o

Anyone know how future additions to blender may address this issue? %|

I know - they wont… seriously, its not an issue. :stuck_out_tongue:

In the Yarfay GI tab in blender set EmitPwr to 30 (or more), and reduce the background intensivity. It doesnt shine, in your renders, beacouse its the same, as if you turned a lamp during a sunny day - it wont give much light compared to the sun and the sky.



Your technicue was very near the solution. I tried fiddeling with the xml-file but thought it took to long time to view the results. Started now again with new interest. And did almoast as before.

Materialsetting for the emitting frourucent tube. is
Emit to max : 1.000
Transulency : 0
Also checked the add VCol Light (dunno if this has anything to do with it)

And now the Yafray settings.
Shadow, Env Mapping, Ray, Radio checked. (do these settings affect yafray?)
xml: unchecked
Auto AA: on
Clamp RGB: on
Raydepth: 10
Bi : 0.001
Gam 1.000
Exp: 0.100 (this one is set to low to compensate for the emit option later)
Method: Full
Qualyt: Actually LOW in this render, took about 30sec to render.
Depth: 5
CDepth: 5
Cache: on
NoBump: off
Photons: on (but dont think it has anything to do wiht thits when there are no light in the scene.)
Just to not babble all the setting as above, ill just note the ones i changed.
Precision: 6
EmitPwr: 100.00
GI Pwr: 0.30

This is the first result ive rendered, and the quality is probably possible able to be increased alot. The main thin is that there are no lights in the scene. There is a sun just to compensate for the ambient feeling. All shadows are renderd from the flourucent lights.

Again all, thanks for helping me out, and hope this will make people try to use new lightning methods. It was actually hard to find anything good about this problem. Maby with fiddeling with balls and other forms as lightsources could be fun.
Happy Blending