Particles and alpha channels and transparencies

[Rampage0007]

I am doing some final renderings in A:M v15, and after reading these boards I decided the best way to go was to do them in layers and then composite said layers together. That way I can use post effects to blus my background and foreground objects.

Except when I render a model that has particle streaks, A:M is putting their transparencies into the Alpha channel even if there is a visible object behind them. (so if I have streaks in front of a wall, and both the streak emitter and wall are to be rendered, the wall should be sorta visible though the transparent streaks. Instead, it is just transparent all the way through. Shouldn't A:M only be applying transparencies to the alpha channel where there is nothing behind the streaks?)

I hope I am wording my question correctly. Hopefully someone else had this problem and figured out what the problem is, as I am stumped...

[robcat2075]

post a targa with alpha channel showing the problem.

 

You might have to render the streaks and wall separately.

[Rampage0007]

So here is an example. if the streak emitter and stage are part of the same model, I cant render them seperatly. The checkerboard I added behind the layer to represent the transparent area

 

[John Bigboote]

Try going into the model itself...select the emitter's CP's...and hide everything else (eyeball, or 'H') Now try that render again.

[Ganthofer]

I understand the problem. I can duplicate it. The Streak emmiter doesn't have to be part of the model for this to occur though. (using V14c)

 

First I would file a bug report with A:M Report.

 

Second I would seperate the Streak emitter from the model and render just the Streak emitter(with alpha). then render the model (the stage in this case)

 

In your example it will work just fine when composited. But if the streaks are in front of the background (stage) and there is nothing to be composited between the streaks and the stage, then why render with alpha on, as this would be your background plate.

 

This of course may not work for what you are trying to achieve.