My goal is to show only on the boarders of the culled particles some particles that emits light, a sort of cloacking effects.
To made this I’ve inverted the noise map (the same of culled particles) and increase a bit the size of noise to cover also the visible particles.
Recently I found an article on emission channel in the documentation section (thinkboxsoftware.com/krakatoa-channels/)
and I discover that the emission channels only refers to the color and not to intensity.
Maybe is that the error?There is another solution to drive my emission strenght with magma flow with a channel map or some function?
Can you post an image of what you are getting when you try to render? Does it fail? Does it now show any Emission?
Also, can you zip up your scene and upload it so I can play with it? (or you can email it to bobo AT thinkboxsoftware DOT com if you prefer).
A few words about Emission:
*>Use Emission must be checked!
*There is an Emission Scale that can be adjusted independently - normally the Emission is affected by the Density, and could get too strong or too low depending on the settings, so you can decouple it from the Final Pass Density by checking “Use Emission Strength” and entering separate values.
*Additive Rendering does Emission implicitly by copying Color into Emission while setting Color and Absorption to 0,0,0, so Emission channel does not do anything in Force Additive mode.
This is what I get when render the scene, the emission channel totally replace my “diffuse color”, why?? I inverted the noise map so is practical impossible, right? dropbox.com/s/by1s98lcnbgogjo/NewSetup.PNG
Remember, the selection map deletes where the color is greater than 0.0, so anything that is not black gets deleted.
Then the inverse map comes and sets the Emission everywhere where the particles were NOT deleted, and every particle gets a strong Emission!
Your Color was still there, but the particle was drawn as over-bright (above 1,1,1) due to the Emission channel, so it appeared to be overwritten. But it was simply blown out.
Using an inverse map is obviously a bad idea, you want the SAME map! But you also need the Delete to remove particles with a different threshold, not just greater than 0.0. This is very easy:
In the existing flow, delete the inverted InputTexture node.
Switch the other node (connected to Selection) from Mono to Color output mode.
Insert a Breakout behind it to read just the R component (after all, R, G and B are equal) - this will fix the selection to delete the same particles again.
Now add a Logic > Greater operator and enter 0.3 in the right scalar - this will now delete particles whose Red component is greater than 0.3 instead of 0.0!
Connect the Color Output socket of the InputTexture directly to the Emission socket.
RESULT: You should get all particles that have a Red between 0.0 and 0.3 emitting a color between black and [0.3,0.3,0.3] in addition to the Color, and the rest will be deleted.
