Maya Iff Z Channel, Reorder Zzzzz Not Work?

[user_deleted]

i can view my z channel (iff file from Maya) with the z view in shake, but when i use the reorder node and set to zzzzz, there's nothing show up when i view r, g, b or a channel. however, i still can view the z channel with the z view.

any ideas why ? i tried turn it into float first, still the same. i even tried use the pixel analys to checked the z channel value, it did show the different value in z.

is it because of something wrong with the Maya (iff) file ? it was render as iff16 bit.

thanks

[user_deleted]

The Z buffer is always float. The renderer needs to somehow encode non-normalised data into usable value and in the case of Maya it is doen using an algorithm which results (from what I can remember) in negative numbers. That means that your range of values might go from 0 (black) to -whatever (less than black). As long as you have promoted your image to float, you can reorder the channels and your image will contain the information, you just wont be able to see it. It doesnt mean that you cant use it though. To see it as a greyscale image you need to normalise the data to the values of 0-1. Try scrubbing the image while looking at the pixel analyser to get the un-normalised values.

I might have some of this stuff slightly innacurate cos it is a while since I have had to deal with a maya rendered z buffer.

Surprisingly, its all in the manual.

[deke-kincaid]

Also there is a tut on turning a z file into something you can see and use here on highend. Just look through the tuts.

[joojaa]

Peple sometimes find the factthat th z depth is in negative numbers bafling. But form a 3d graphissists point of view itrs ovious since the camre cordinate spce is aa transform and we use a righthanded cordinate system. Thet means thet because we like to thing x as up and y as gight z is pointing towards us. THus everyhthing in the camera projection is nagetive.

Just another thing you should know maya Zbuffer ius encoded in a -1/depth way. so if somethings 30 usnts away itll register as -1/30

take alook at how the zviewer lookupscript works it explains it all. Even how to normalize the image. TOugh if your aim is tio sue z for things as dof etc DONT normalize it. Otherwise itll shift on you.

[user_deleted]

thanks

i think the view z scripting is just for viewing (the normal,standard, distance setting), it does nothing to the actual z channel.

the shake user tutorial just mentioned the z view scripting and the maya 0/-1 z channel, it didn't say how to change it, only said download the macro from highend

the tutorial in the highend here about the z is great, and it actually tell us how to change it using the color mult. question again, isn't that by using the color mult () we will push the distance further away ? say 1 and 0.5, the distance is 0.5. but if we mult () it by 10, now it become 10 and 5, the distance now apart now become 5 (although the % still remain the same). is it better to use add instead ? 1 + 10, and 0.5 + 10, the distance apart still 0.5 (of course, we need to *-1 to turn it positive first).

thanks