DOF (2)

[wurp]

Is there a way to link the distance value in the DOF lens shader to the distance between a camera and an object? This would be good for animating a scene with DOF where the distance between the camera and the objects keeps changing.

Also, is there a way to simply copy and paste a material onto another object?

[atyss]

Bonjour wurp,

Go check this link:
http://grabiller.3dvf.net/site/content/tut...ispass\_eng.html

This page describe a way to generate a DOF pass that is to be used in post. However, you could use very similar expressions to link your DOF instead of playing with colors.

As for the copy paste thing, open an Explorer, expand the source object, select its material, hit ctrl+c, now select the target object and hit ctrl+v. It's done!
Don't forget that it is better to group your objects and apply a material to this group (thus propagating the material on each member of the group), instead of copying the same material on many objects. Also, you can parent make your objects child of a null, branch select this null, and apply a material on it (propagating the material down to its children).

Hope this helps
Salutations - Cheers
Bernard Lebel

[withanar]

Sure. Turn on the DOF effect and switch it over to custom. The start & end distance parameters will become enabled. Get a couple of nulls or implicit objects and link their distance to camera with the start and end DOF params.

[wurp]

hi and thanks for the reply, but errrm....how do I link the didtance between the two nulls and the near and far focus in XSI?
I kinda need a step-by-step guide...

Thanks

-Andreas

[ottscay]

Andreas,
Unless this is more for your own knowledge (that is, not for production), I would say forget about 3d DOF and do it in post. I'm sure lots of other apps has good DOF filters, but I use Commotion's True Camera Rack Focus, and it's a godsend. It's much faster, and you can tweak the results more interactively. The bottom line: Better results in _much_ less time. Good luck either way!

Scott

[atyss]

Scott, I have a question of you.

How does Combustion deal with Softimage Zpic files? In my case I use After Effects, however when I apply DOF using the z-channel, I oftenly get artifacts and jabbed edges. This results in that most of the time I don't use DOF at all.

Does Combustion give better results? I was at the Combustion 2 presentation. The DOF was great, except that the guy was only using .rpf files. However he didn't show how Combustion behave when it comes to zpic.

Can you bring light in this please?

Merci - Thanks
Bernard Lebel

[richard-sher]

You can minimize the artifacts that you get when using AE to do DOF by rendering larger images, running them though the DOF process and scaling them down. Not the best solution, but it works.

[atyss]

Bonjour Ed,

Thanks for the reply. What do you suggest as a decent size? Somewhere I read that twice is the ideal.

I saw in one of your recent posts that now you rely mostly on the FXTree. What do you think of it in terms of DOF? Do you have to go trough similar issues as in AE?

Merci - Thanks
Bernard

[richard-sher]

Twice the size is a good start. I usually do a couple of test res renders first to see what's best. If I can get away with smaller renders, then great. Otherwise, I'll have to go larger. I do usually use the FX tree. But as far as I know, it does not do depth effects (using zipcs) yet.

[richard-sher]

Twice the size is a good start. I usually do a couple of test res renders first to see what's best. If I can get away with smaller renders, then great. Otherwise, I'll have to go larger. I do usually use the FX tree. But as far as I know, it does not do depth effects (using zipcs) yet.

[ottscay]

Andreas,
Sorry, I don't use Conbustion, though I've heard good things about v2. If you are having trouble with zpics, just render out your own depth map movie. Create a copy of your scene and name it "yourscene_depth" or some such thing. Set all your objects' materials to constant shaded black. Then add a global white fog to your render pass.
Ideally, you want to measure the distance from your camera (unhide it) to the objects that get closest and furthest to your camera during the scene.
Then, set the fog parameters so that it begins at a distance that coincides with the closest an oject gets, and becomes opaque at the furthest distance an object gets from camera (this provides more accurate information for your 2d filter to work from).
Because you can crank up the antialiasing, you won't have to deal with artifacting. Once you've done it once or twice, you can set up a scene as a depth matte in like five minutes, and it renders quickly. Then use the output as the depth matte layer in whatever DOF filter you use.

If you have any problems you can email me.

Scott