funny zdepth map !

[appius]

i can't get a zdepth map with the vray frame buffer...
here is what i get:



if I try to save it, i got a black picture.

seems also that it doesn't work with DR..

[percydaman]

ya its been said before. The information is correct apparently, but you would have to save as rpf/rla I guess to be able to use it. Strange.

[RErender]

not really strange, it is saving actual numerical data not grey scale. It would be cool to have a another layer with a grayscale depth.

[percydaman]

exactly. which is why i called it strange. Why not just output to grayscale like the scanline renderer.

[appius]

outputing to greyscale?
here you are...
nice, isn't it?

[RErender]

easy enough to convert it to greyscale from a rpf in combustion or the like.

[Morbid Angel]

yeah i posted the original thread, however I found that rpf/rla make combustion crush often with this zdepth info...also zdepth can be used for other purposes then just zdepth, like selection mattes. So it is very much so needed for vray to render normal zdepth as we know it. On bsg i had to render zdepth with mr....which sucked because motion blurs didnt line up...

[appius]

the trouble is there's nothing to save but black pixels...

[Morbid Angel]

i think in some cases...you can do scanline zdepth with camera multipass blur if you have moblur as its the closest to what vray does.

[appius]

the trouble is i'm using some vrayfur, and default scanline can't handle it.

[Morbid Angel]

thats dope...there is always a fog approach...which is a cheat, where all materials are set to 100 self illum, and there is atmospheric fog, which mimics zdepth (we used to do it with maya)

[percydaman]

ya not everyone has combustion... vray should have option to render out usable zdepth without forcing you to use combustion or really any other program to use it.

[vlado]

It's rendered quite correctly, but exporting to an image is somewhat problemmatic - you will need to define the white point and the black point distances yourself. When 3dsmax creates the z-buffer, it only shows it as a grayscale image, but in fact the underlying data is a floating point distance in camera space. Typical 24bpp file formats do not have enough precision to store z-buffer information. Only .rpf files are capable of storing the actual floating-point data (and recently, .exr).

Best regards,
Vlado

[tom schuelke]

Hi the approach to do more but a greyscale immage is a good approach.

in our previous company, they tried to use grayscale z-depth out of max for a larger city animation.

what we found out was, that the available 256 grey collors didnt bring out enough information to do smooth depth. So a floatingpoint solution is the better approach.

now i also would like to have a switch to use it as i want , greyscale or floatingpoint.

Tom