How to...compose yafray and internal renders?

Here’s my problem: in an animation i am working on, i need to use yafray for GI and other stuff, but i also need the halo particles. I tried to fake the halo, but i cannot setup a similar mesh/material and the effect is really bad. So i would like to render my animation in yafray, than render the particles (and in some way retain the z depth informations) to later (somehow!) compose the 2 passes, so that i get particles going behind characters wehn tey0re supposed to. Any idea on how i could procede to get what i need? (Best way would be to mimic the halos in yafray, but i havo no clues aside from trying with meshes/dupliverts and materials).
Thanks a lot for reading 'till here, and thanks for helping if you will :slight_smile:

i also tried dupliverts with lamps, enabling yafray glow, but the result (not bad) is not strong enough, and i have every parameter to its max…

Ok, I’m not sure about the specifics of your scene setup, but I will take a guess and maybe you can apply it. :slight_smile:

You would render into an image sequence, not a video file. I suggest PNG or Targa. For Internal, make sure the world is black. What you will do is add an alpha channel to each rendered frame, and everything black will be deleted. In the render buttons (F10) select Premul in the Render panel and RGBA in the Format panel. Again, make sure you have an image format set that supports alpha. When you click Anim, it will render your animation normally, but instead of a movie file, you will get a list of images, each one being a frame, in order (ie frame0001.png, frame0002.png, etc). This will be your halos, so turn everything else off.

Then switch to yafray and do the same thing for the objects that need the GI, but without the background. (I am pretty sure Yafray will export 32 bit PNGs/Targas like Internal.)

Then render your background, but without an alpha channel. Now you have 3 layers. Composite them ontop of each other in the correct order in whatever program you choose, such as the sequence editor in Blender.

Hope this helps. :slight_smile:


That should work :slight_smile:
Thanks for your help. I am now rendering a last try to see if i could use lamps as particles in a single render pass, and from static shots it seems decent. Otherwise i’ll go your way :slight_smile: