db&w Support Forum

hey,

just started a few days ago with that exr stuff! i´m now on a point right now in fusion where i´m in confusion ,)

a scene was rendered in lightwave using exr-format, every channel included to one image file (rgbaz). load up in fusion, some color corrector applied, think looks good.

right after the loader and the cc i´ve pushed a depth-blur channel. ok. so, what the strange thing is at that point, the z-channel in the exr loader shows as full white!

in the loader all the channel-links are correct, everthing where it belongs. if i change and show up the z-buffer in the alpha buffer and take a look at it, it shows me the
z-buffer correctly. ???


somebody some ideas?

thx in advance!


   sascha

Are you normalizing the view in Fu5 when viewing the Z-Buffer?
If you don't normalize it, Fu5 will display the range from 0 .. 1.0 only, anything beyond that is white, anything below black. The Z-Buffer export from LW is likely to be mostly white then since in most cases objects are am or more away from the camera.

Cheers,
Mike

 ;D - thats it! i see it! thank u!

but seeing not necessary meens working  :-\

to simpler explain myself, i attach here an image!


http://transfer.shenom.net/shenom/flow.jpg


i can pick the focus point, but every other channel don´t seem do change anything. some idea?


thx in advance

   sascha

Try lowering the Z Scale to something like 1.0, or even 0.1 and play with the Depth of Filed in low ranges.

It seems that the default settings in Fu5 are made for RPF/RLA files, which store the Z in different ranges.

Cheers,
Mike

again  ;D

u need 2 use extreme low values. around 0,001!


thx alot!


   sascha

Great. Yeah, it seems the defaults are catering for the (different range of values) Z Buffer embedded in RLA/RPF files.
You can always try to find some decent LW settings and save them as a default for the tool in Fu5.

Cheers,
Mike

I've been facing the same problem but with depth fog. Unfortunately fusion won't let you use a Z-scale any smaller than 1.0 for fog. Try as I might I could not get decent fog. (All I could get is the background completely fogged and nothing on my test objects. That or no fog at all, it seems mostly because I can't get the scale down small enough to get any good gradation)

That said I've been fiddling with the scale of my lightwave scene, the z-buffer scale in EXRTrader, so far I can't seem to find lightwave settings that will do the trick. I'm wondering what is the scale that RLA/RPF use? Perhaps then I could find the right settings.

Hi,

I have no idea actually (RPF scale), however, I'll have a look. You could of course always render out a frame with RPF using LW to compare the values.

I have to admit, I haven used the fog much in Fu5, I'll check it out once I have a spare moment (sorry, things are a bit crunchy at the moment).

Cheers,
Mike

Thanks for checking into it, I've been doing some more digging. It appears that it is a common problem. Common enough that a company sells a DF5 plugin to deal with it.

Here is a link. (http://laffey.tv/ztool.html). I may just get this plugin for now. But if its just a scale thing, I'm hoping I can find Offset and scale settings for EXRTrader that will do the trick. One less node to worry about in the flow.

Nothing wrong with Joe Laffeys plugin, but I don't think you'll need it.

The Min/Max settings for the Depth buffer behave a bit differently for exrTrader. They basically define the distance to the closest and furthest away object/position in your scene.

As a first test, you can guess them using the grid, if you want to autmate it, you can add two Nulls to the scene and add an expression to the exrTrader envelopes to set the min/max to the distance of a specified camera to the Nulls.

I'll set up a sample scene over the weekend to show how this works.

Cheers,
Mike

Good news, after much fiddling with EXR Traders settings, particularly the scaling option, I have had some success. It appears that Digital Fusion smiles upon a depth buffer multiplied by 1000. Don't go above 1000, some sort of clipping seems to occur at that point. Also Digital Fusion seems to want the z-buffer inverted. At least the depth functions seem to work more predicatably that way.

I can't claim any significant mathematical knowledge as to why it seems to work this way. I arrived at my solution via trial and error (numerous test renders).

Lol, sometimes that seems to be the only way. Good to hear, thanks. Hm, I guess this whould be part of a Fu5 preset then.

By the way, if any of you have actually created some presets, I'd love to make them available ot other users.

Cheers,
Mike

Any tutorial on how to use exrTrader depth values in DF5 would be greatly appreciated.
Screengrabs or maybe even a camtasia tutorial would be awesome!
Best Regards,
Zareh

Yup. I've got a capture tool installed. I was planning to create some to show off exrTrader (and infiniMap Pro). You'd have to bear with my voice though ;)

Cheers,
Mike

 ;D
cool! Looking forward to it Mike.
take care,
Zareh