Animating Depth Of Field - VRay

[TomElcott]

Hey Guys,

 

Iv recently started playing around with some DOF using the VRay Physical Camera. Im really struggling to get any DOF in my rendered image... I know i can use the Z-Depth Map rendered out seperatly, but i want to use the DOF in an animation and i dont want to use masks or anything like that...

 

Basically what i want to achieve(if possible) is that my VRay Physical Camera Target is my focal point with regars to the DOF, so if i move the Camera Target to another object, the DOF will change as it moves from one object to the next, making the first object then blurred and the "back" object my new focal point in focus...

 

Im pretty sure its quite clear what i want to achieve, but in case im not clear, i want to get a similar effect as alex roman's piece, -third seventh- with regards to how he has used the DOF...

 

I have read many tutorials on DOF and most of them i cant seem to get to work with just pressing render, i can get it to work with the Z-Depth Map, but that is not my goal...

 

All help will be greatly appreciated

 

Tom

[azeta3d]

hey there! first of all, rendering the dof directly form the camera will increase a looooot the render time, maybe on a still image you can live with that, but when rendering an animation means maybe 4 hours of extra time, personally I add a z depth map as render element and then make the DOF in after effects, combustion, ps or whatever.

But well, if you want to experiment with the camera DOF i think the key to do that is to animate the specify focus value. If you want to focus in a near object and then on a far one, just add a key with the first focus and then another with the distance to the second, that should blur the first and focus the second. Should tweak maybe the timing on that, but for sure it will work.

Hope it helps you, cheers!

[TomElcott]

At the moment im getting absolutely no Depth of field? I cant think what im doing wrong... If i tick the Specify focus box then change my focal Distance it doesnt change at all? Also though this is not the way i want to get it working... i would prefer it if i could animate my Camera Target and the DOF changes with the Camera Target movement... If this is possible?

 

Here are my Camera Settings... Sorry i dont know how to post it bigger but if you click on it it opens bigger...

[ATTACH=CONFIG]38808[/ATTACH]

Edited August 23, 2010 by TomElcott

[STRAT]

i'd consider doing things like dof in post, whatever you think. it'll make life much easier for you. post is a non-destructive and flexible process that all the pro's use. rendering dof in the renderer is so time consuming and inflexible. post is just as realistic if not more so.

 

i use DOFPro personally

 

if you do want to proceed in the renderer the first thing you need to crack is the basics of your camera. get basic dof under your belt. then practice up and down with the sliders and different spinners to familiarize yourself with it all. get yourself a whole extreme load of dof going. this'll get you on the learning trail.

 

I done a quick tut on the vray camera. take a look at the principles of it. it's a specific C4D tut, so i dont know how it'll translate over -

 

http://www.buzzbox.eu/content.aspx?pid=33

[TomElcott]

Thanks Strat, I just went through your Tut and it was very helpful!

I think the idea of getting to know how the F-Stop And shutter speed etc effect the image is probably the right place to start...

[TomElcott]

My Biggest problem with doing it in post is that If i want to animate my camera focusing from one object in the for ground to another object in the back ground i will have to render the animation more than once... So time of render aside, i still need to render the animation with DOF on the image before doing any post work...

[azeta3d]

Well, to do it in post you might have to render 2 different z depth maps, one focusing on the foreground and the other on the back ground. Then when rendering is done, mix those 2 maps in any video editor making the first smooth fade into the second in the time you want the transition, then save it as a image sequence, and there you have it, an animated z depth map ready to make an animated DOF in post. Hope it works, cheers!

[Nic H]

My Biggest problem with doing it in post is that If i want to animate my camera focusing from one object in the for ground to another object in the back ground i will have to render the animation more than once... So time of render aside, i still need to render the animation with DOF on the image before doing any post work...

 

no you dont - use a vray extratex element (or 2 or 3 or 4 etc) with a falloff set to distance blend and put near and far ranges in.

render to 16bit and do it all in post - it will look much better and wont kill your render times.

[STRAT]

With dofpro you only need render a single zdepth map - you can fully animate and differentiate the focal lengths most naturally. Most good post dof processes allow this full range of animated editing

[azeta3d]

With dofpro you only need render a single zdepth map - you can fully animate and differentiate the focal lengths most naturally. Most good post dof processes allow this full range of animated editing

 

wow, does DOFpro work for after effects?? it would be a nice plug in to take into acount!

[Tommy L]

Aftereffects will do this also. You just animate the focal point (as a grey value) in the DOF parameters of lens blur effect. You need to render a z-depth pass with black and white as your extremes of depth focus max/min distances specified in the Render Elements panel.

If you are determined to do it in the render engine....I think it sounds like you probably missed the enable check-box in the camera section of the render panel.