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kriscabrera
07-28-2007, 08:50 PM
Hey guys i am kinda rusty in afterburn since i havent used it in a while but i am getting some banding on the smoke heres a pix for a better look, but i have did alot of process of elimination but i can seem to find out what the banding is maybe you guys can help thanks.

SoLiTuDe
07-28-2007, 09:43 PM
Try lowering your step size... how big are your spheres and what is your step size?

kriscabrera
07-29-2007, 12:32 AM
My step size is set to 6.0 and my spheres start at 5 and reach 30
Thanks for the help

SoLiTuDe
07-29-2007, 03:03 AM
bring your step size down do 1 or so, possibly lower -- depending on how it looks. Have the step size larger than the sphere size will make it look nasty... you may basically get one or two samples out of the entire sphere near the beginning which will look gross. :)

BrandonD
07-31-2007, 03:18 AM
A quick explanation on Step Size:

When a volumetric renderer traces through a volume, it takes samples along each ray as it's cast through that volume. Step Size is the length between each step or sample. This means that low values produce more samples and larger values cause the renderer to "skip" through the volume. More samples = more accurate but slower. Imagine a car driving through a tunnel full of pictures hanging on the wall. If you only stopped every fifty feet to take a photo of the inside of the tunnel, you won't get as detailed a record of what's inside the tunnel vs stopping every five feet.

Now it's important to note that there are times when a larger Step Size is advantageous. First, when doing quick draft renders where you just need general color info. Second, when you have a low density volume it's often not necessary to do lots of detailed sampling within because there's not much detail to begin with. On the other hand, if you have a very detailed, dense volume, you'll want a small Step Size.

Here's where I usually set it:

Density 3.0 Step Size 0.5
Density 2.0 Step Size 1.5
Density 1.0 Step Size 2.5
Density 0.5 Step Size 3.0

kriscabrera
07-31-2007, 07:12 PM
thanks for the tip brandon it is very useful =) i understand it better now,
thanks for the help guys =)

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