PDA

View Full Version : Node Image Filter Best Practice



dulo
11-04-2010, 11:40 AM
In the Screenshot I have a simple NIF to blur the Background channel.
Even this simple setup took me quite some time to figure out, it works, but it still seems wrong somehow. Why would the Store Extra Buffer Access knot overwrite the color in the input node, but it doesnt overwrite the Alpha Channel like in the screenshot ?
Isnt there another way to trigger the branch of this node network than to fiddle around with the Access knot ?
Is it implicitly clear that the Get extra buffer Node is evaluated after the image filter branch ?

Is this node setup valid ? or is there a more elegant way to do it ??

dpont
11-04-2010, 12:36 PM
Is this node setup valid ?

Store Extra Buffer node is useless here,
you should rather mix the blurred background
with the foreground and an alpha channel,
but I don't think that blurring the background
in a post process is a good idea.



...or is there a more elegant way to do it ??

Use the Image Filter NE as preprocess
in the Image Editor for your background image,
Render Buffer Color output -> Fast Blur -> Color input.

Denis.

rezman
11-04-2010, 08:03 PM
I never thought I'd see the words "best practice" in a Lightwave forum. :help:

dulo
11-05-2010, 03:33 AM
This whole setupup is just a test without any real sense. I just wanted to be able to generate new image filtered buffers without affecting the color or the alpha of the rendering. Therefore the store extra buffer and the get extra buffer to save the generated channel.

I am also unable to make this setup multithreaded. I always stays on one cpu. Should it be able to use more cpus or does multithreading mean in this case that it could evaluate some nodebranches simultaniously ? Meaning is it even possible to "multithread" eg. one FastBlur node ?

dpont
11-05-2010, 04:32 AM
This whole setupup is just a test without any real sense. I just wanted to be able to generate new image filtered buffers without affecting the color or the alpha of the rendering. Therefore the store extra buffer and the get extra buffer to save the generated channel.


In this case, since the "Access" output of Store Extra Buffer
is always zero, connect it in a Math Scalar Max node with
the original Alpha of Render Buffer node and connect the
Max node to the Alpha root input, check "Replace Buffer"
for Alpha in the Image Filter node editor.


I am also unable to make this setup multithreaded. I always stays on one cpu. Should it be able to use more cpus or does multithreading mean in this case that it could evaluate some nodebranches simultaniously ? Meaning is it even possible to "multithread" eg. one FastBlur node ?

In postprocess there's just Multithreading in Pixel Filter NE
for AntiAliasing and this is managed by Layout,
A lot of things are not compatible with Multithreading.

Denis.

dulo
11-05-2010, 09:05 AM
Thanks a lot for your help. Things already start to get clearer ..