Particle Systems

I have used the ubiquitous particle generated smoke for the following example as the change in appearance is very obvious. The jpegs above are the same frame from a moho file with one small change - the one on the left has been rendered with no masking effect, while the one on the right has had the masking option activated. Neither image is superior to the other; each has a look which would be more effective in different circumstances. The smoke in the frame to the left looks more like wood smoke, whereas the frame to the right has a greasy feel, much like a tire burning.

Moho Layers Box

The jpeg to the immediate left shows the layout of the layers box. The particle layer with its sublayers was placed into a group layer.

Group Properties Options Box

As you can see in this screen shot, the 'Use Lowest Layer As Mask' option is checked (circled with the orange ellipse). This is the way that the 'greasy looking' smoke was created. To achieve the 'wood smoke' look, this option was left unchecked.

I was going to offer the two .movs as a download, but the Sorenson compressed version eliminates most of the subtilities and the animation compressed version is too big for such a short clip. I am therefore linking to the .moho file which you can dl and render both ways on your own machine (for best results I recommend 'Animation' compression with 'Best' quality).