is there away to order the which particles are rendered? im trying to create an engine with a flame(which i want ontop) and a trail of smoke. the problem is that the smoke is rendered over it and you can’t see the flame… any suggestions?
Try rendering with the Unified Renderer.
Martin
I tryed that now im getting a black hole effect with a halo im using
Seems to me that I read somewhere that that is a bug in 2.3, I think it will be fixed in 2.31. Until then use 2.28, it does halos correctly.
aha, I had the same problem with halo’s and the unified renderer in 2.3
Seems I just gave to wait for the next version.
As a workaround you can always composited the output of 2 diferent renders.
Alexandre Rangel
Well I’ve found that you can achieve semi-decent results using Key as opposed to Premul or Sky for the alpha calculation. Though I found that in the Unified Render you’ll get strange results if you’ve got envmaps.
Sky:
Render:
Particles completely disappear, when directly infront of the world.
Envmap:
Particles will show with the proper color world. Dithering is somewhat better than Key
Premul:
Render:
Particles will appear with large black boxes, when infront of the world.
Envmap:
Particles will show with a black color world. Dithering is excellent due to apparent black based alpha calculation of particles.
Key:
Render:
Particles will appear similar to the envmap particles of Sky. Dithering is slightly reduced in quality with a good deal of black visible.
Envmap:
Particles will appear quite blocky on proper color world. Dithering is non-existant. Particles will appear to have a flat color that fades near the edges.
Doubt any of that is actually correct, but feel free to correct me if you are more intimate with the details of the particle system. If you would like some visual samples I can create some.
To counter the effects on particles over the world best, create a simple plane behind your objects. Then give the plane a shadeless material with the color of your world.
tell me, is premul different than premultiplying the alpha?
iirc the equation for alpha blending is: (assuming opaque background)
new_color = dest_color*(1-src_alpha)+src_color*src_alpha
and for a premultipled texture it is:
new_color = dest_color*(1-src_alpha)+src_color
(is that what premul is for?)
Premul means exactly that. Premultiply the alpha with the RGB data.
Key keeps the RGB data intact and uses only the alpha channel to do the blending (hence transparency using Key will look weird if you only watch the RGB channels).
Martin