post dof

#1

Could/would someone point me to a tutorial or tip on how to do depth of field in dxf?
For example, is it possible to use a grayscale image to control the effect?
So that the white areas would be sharp and the darker areas would blur.

All regards,
Pensart

#2

This one will show you the priciple:

ftp://gecko.newtek.com/multimedia/eyeon/DepthFog.mov

Cheers mate,
Andy

#3

Thanks for the reply durexlw but its not what i was after.
I found a way to do it. All i needed to do is use the grayscale image
as a mask on a blur node. And it really looks good! Depth tools in Dfx
only work when u have a zbuffer in your image.

#4

Depth Blur node has has an additional input slot, so you can use a separate image for your blur.

#5

Hi wiz, i did different attempts but i cannot get it to work. That’s why i was looking for a tut.
I have very little to none experience with dfx or other compositing software.
I will give it another go.

#6

In order to use the z-buffer with the dept blur tools you need to use the channel boolean tool to copy the z-buffer image into your RGB image.

  • connect the z-buffer image to the foreground input of the channel boolean tool
  • connect the RGB Image to the background
  • set every channel under “Color Channels” to “do nothing”
  • under “Aux Channels” set copy red foreground to z-buffer

Now connect the channel boolean to the depth blur tool.

The easyest way would be to use an image format that contains a z-buffer like RPF.

Florian

#7

Thanks Limbus!!

I did what u described but when i look at the zbuffer “from the bolean node” only. The zbuffer image i used is way f#c# up. But i get the idea and will play abit more with it. Looks like an interesting setup.

#8

Thats OK. DF somehow normalizes the image. But now you can pick the point in focus in the depth blur tool.

#9

Has anynoe had any real luck with post dof in fusion? I mean i know how to do it, but i can’t ever get any real acceptable results. When two objects overlap, fusion sucks at edge detection. And the blur doesnt account for boheck(or however you spell it) effects. I’d be curios to see if people have made significant use of it.

#10

thought id post an image of the problem.

Im rendering out a depth pass, and then channel booleaning the RBG into the ZDepth channel. The blur works fine, but as you can see, it has trouble with the edges, and i have never been able to get it to work.

#11

It’s not Fusion that’s messing up the DOF, when two objects overlap the final RGB output is anti-aliased to smooth the edges… You can’t properly AA the zbuffer image as it will make the edges seem to be at the wrong depth, you have to use a zcoverage channel (although I’ll admit I’m unsure of how to use it in Fusion, and can’t test it out right now).

The image with the messed up DOF - could you post the RGB and zbuffer images? Are the golf balls displaced and the zbuffer image is of non-displaced spheres?

#12

I had same problem using the Z-depth to compose images, and yes the edges are aliased, but if you turn on the Motion Blur option insdie the emrge node you will get a nice smooth aanti-liasing , plus you can use a matte control over your images to smooth a little your footage ’ s alpha channel. Another fact is really “deep” z-buffers seems to become usntable and produce weird results when more than 2-3 layers are composed, and PLUS usign z-depth from mental ray is quite diferent than using from Software render ( assuming youa re using maya and iff format )

#13

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