ZBlur dof question

[Tuvshoo]

Hi. i can't make the dof effect in Nuke. i know it's zblur but i tried a lot no result. my z depth rendered with mental ray in exr. i'm making dof effect in after effect using lens blur and want to make it in nuke. can anyone give me a little bit detailed instruction how to use zblur node. thanks.

[Tof]

Hi,

Be sure that your Depth channel is correctly graded. You can check that by roll over your image in the viewer and check the depth value. Usually, you add a grade node for the depth pass, to adjust the values between 0 and 1, and then you add your zblur node.
Then use your depth.Z as depth in Z of your zblur node. You can activated the focal-plane setup to adjust the focal plane value
Personnaly I prefer to use the convolve method that will give you a much better result, but that's an another discuss

Enjoy.

Christophe

[Tuvshoo]

a haa. it works. thanx a lot for reply tof. i rendered depth pass in separate file and made mistake on channel copying later. some setting are hard to understand. can u explain me about convolve method? kkk. thanx again. best lucks to you. :-)

[Tuvshoo]

a haa. it works. thanx a lot for reply tof. i rendered depth pass in separate file and made mistake on channel copying later. some setting are hard to understand. can u explain me about convolve method? kkk. thanx again. best lucks to you. :-) .

[Tuvshoo]

a haa. it works. thanx a lot for reply tof. i rendered depth pass in separate file and made mistake on channel copying later. some setting are hard to understand. can u explain me about convolve method? kkk. thanx again. best lucks to you.

[lucienfostier]

hi there,

another useful method is to use an expression node on the depth pass

to do that

append the expression node and in the first field selected your layer (ie= rgba if you render you pass in that layer or depth.z if you already copied it there)

then type

abs(Z) in the expression field

you are free to mult this result by whatever make sense.

after that you can add a grade operator and use the black and white point to either compress or expand your depth without breaking the gradation as a mult or gamma would.

this can be helpful to create depth based mask to color correct, and this can also enhance the different level of blur between your out of focus elements and sharp elements, but be careful of not breaking the realism too much.

have fun

[Tof]

hi all,

just to complete the lucien's post, the absolute method will works if your ZDepth value are only negative (positive doesn't require abs), unless you'll get a mix of transposed values and other that still positive from the original datas. So in some case (depending of your 3D software) it could works, and sometime not.

Enjoy !