*.mt & *.Zpic formats

[gk2k]

XSI renders out motion vectors & Z-chanel in *.mt & *.Zpic formats. What compositing software cam import and use them ?

[richard-sher]

I know that After effects can use zpics and Shake can use motion vectors, but I am not sure if the opposite is true.

Ed
XSI Videos, Tutorials, Tools, Shaders....
Available at:http://www.EdHarriss.comhttp://www.EdHarriss.com

[mike-lasker]

After Effects uses Zpics pretty well for depth of field, although the Zpics aren't anti-aliased, so sometimes you get jagged edges on objects in the foreground.

[wolfinger]

excuse me, but how do you use zpics in AE?

I got a zpic file opened in Photoshop, using the rawfile format, but the result was quite odd. The zpic had four channels, out of which the "red" channel was just about empty, just a little outline barely visible, the "green" channel was a recognizable depth channel, although a "buggy" one, the "brue" channel was just... weird*..., and the "alpda" channel seems to be pure noise, but only in areas where there are objects (no noise over the background).

I'm making a wild guess here... since 8 bits is ridiculously little as a Z-buffer for compositing & effects work, the various channels are somehow different orders of magnitude for the depth.

What I need is some way to extract the data, and use it in Photoshop and After Effects. Are there any tools for this?

(* the weird channel looking something like mostly circular patterns of black&white lines that trace the shapes of the various objects)

[devdoka]

The mental ray Zpic is a binary file containing a single channel comprised of single precision (32 bits) floating point values representing the depth between the camera and the intersection point.

The reason you're seeing garbage is because AE is trying to open the file as 4 channel RGBA with 8 bits per channel. Each 32 bit float value from the file is getting chopped up into 4 pieces each representing a pixel within the assumed color image.

I don't use AE, so I don't know how to make it work for you. The best I can say is to find a way to convert the depth information to a readable format whether it be another scalar based data type or an RGBA color data type.

You might get better results rendering a 16 bit per channel color image for your depth passes. That way instead of getting 256 possible depth values like in an 8 bit color image, you can get 4096 depth values per pixel. I know, not as good as a true floating point depth image, but it should be plenty fine if you're working at broadcast resolution.

I assume AE can support 16 bit images?

Matt

---

Matt Lind
Animator / Technical Director
Softimage certified instructor:
Softimage|3D
Softimage|XSI
speye_21@hotmail.com

[wolfinger]

I tried rendering with 16 bits per channel, but the .Zpic didn't change at all, it was still the same.

I could whip up a simple program to convert zpics into 16-bit monochrome tiffs or something, but if there's a ready program for this purpose I'd rather use that than spend time reinventing the wheel.

[richard-sher]

In reply to:
excuse me, but how do you use zpics in AE?

since 8 bits is ridiculously little as a Z-buffer for compositing & effects work, the various channels are somehow different orders of magnitude for the depth.

If a directory contains an rgb image and it's corresponding zpic then after effects loads the zpics automatically when you drag the rgb image into it. Then you can right click the image and choose some of the effects in the 3d Channel menu. (like DOF, Fog3d or 3d Channel Extract).

Here is an example I created that uses zpics to create a DOF effect in AE.

The 3d channel extract is just what you are looking for to create an rgb image out of a zpic. (This way you don't have to write a tool for it)

Yes, Zpics are 8 bit. But to overcome some of their limits, I usually render out images that are too large for the desired output and scale them down just before putting them to tape. (this helps remove artifacts)

Btw, All this stuff is covered in greater detail (including a couple of examples using after effects) on my Rendering tape. http://www.EdHarriss.com/tape/http://www.EdHarriss.com/tape/

Ed
XSI Videos, Tutorials, Tools, Shaders....
Available at:http://www.EdHarriss.comhttp://www.EdHarriss.com

[wolfinger]

I have After Effects 4.0 (for PC), I guess that is too old. I can't find any references to Zpics anywhere.

I'll just make a quick program to read the Zpics and output either 8-bit int, 16-bit int, or 32-bit float monochrome TIFFs. Should be easy enough, and then I can use the TIFFs in any program I need to.

[devdoka]

@@ I tried rendering with 16 bits per channel, but the .Zpic didn't change at all, it was still the same.

That's because a Zpic, as mentioned earlier, is a floating point format, not RGBA. If you render using the depth texture shader (or depth pass) into a 16 bit RGBA color format such as tiff, tga, sgi, etc... you should be able to bring that into AE without problems. Just make sure you set the image format to 16bit from your render options.

Matt

---

Matt Lind
Animator / Technical Director
Softimage certified instructor:
Softimage|3D
Softimage|XSI
speye_21@hotmail.com

[wolfinger]

The Depth pass trick works excellently, than you very much!

I think I'll make that zpic translator anyway though, or at least the interesting parts

[gazzmills]

In reply to:
The Depth pass trick works excellently, than you very much!

I think I'll make that zpic translator anyway though, or at least the interesting parts

hi you all, fess I think there's allready a program to convert zpics into rgb images right here in highend 3d/softimage tools.
I know it was here sometime ago, not sure about know.
BTW Ed. how do you make after effects work with zpics, i have tried it out several times but i always get an error message, something like zpic file error out of range or something like that, not sure about that message, don;t remembre. But it happens all the time, i have tried rendering my zpics ( and the rgba) files on sgi and NT, and on both i get the same error message, and yes my zpic files are in the same directory as the rgba. thanks in advance..( and sorry this is not an AE forum, but since you guys mentioned what i;ve been trying to solve for some time......)

[richard-sher]

Like you said, if the Softimage pic images and their corresponding Z-pic images are in the same folder then After effects should load them automatically. I don't know why it is not working for you. I believe that you need After Effects 4.1 or greater to make it work. Maybe you have an older version. I haven't seen the error that you are talking about. There might be a need for you to load the softimage.pic plugin. But I doubt it.

Ed
XSI Videos, Tutorials, Tools, Shaders....
Available at:http://www.EdHarriss.comhttp://www.EdHarriss.com

[gazzmills]

In reply to:
Like you said, if the Softimage pic images and their corresponding Z-pic images are in the same folder then After effects should load them automatically. I don't know why it is not working for you. I believe that you need After Effects 4.1 or greater to make it work. Maybe you have an older version. I haven't seen the error that you are talking about. There might be a need for you to load the softimage.pic plugin. But I doubt it.

Ed
XSI Videos, Tutorials, Tools, Shaders....
Available at:http://www.EdHarriss.comhttp://www.EdHarriss.com

Thanks for answering Ed, this is the exact error message I get:
After effects error: reading from file "NAME OF FILE.1.zpic" - unexpected end-of-file (-39).

I kept on trying and I found out that if the zpic file was rendered in the softimage renderer i always got that error, but since you guys mentioned mental ray I gave it a try and rendered with mental ray's zpic, and it worked. Don;t ask me why, but after effects can;t recognize zpics rendered with the default softimage renderer.
Thanks Ed for pushing me to keep on testing..... = )

[devdoka]

The Zpics coming from the Softimage renderer are slightly different from those made by mental ray.

The old Softimage renderer wrote it's algorithm for Zpics way back in the late 80's/early 90's before the arrival of mental ray. In those days, saving a few bytes of memory meant speed. Remember - a machine with 16MB RAM was considered luxurious in those days. Soooooo, in light of that, the Softimage renderer employed a type of short-ending of Zpic files. That is, no more data will be written to the file after the last object is sampled in the frame. Therefore, if you had a sphere in empty space cenetered in the frame. The softimage renderer would not write any more data to the Zpic file after it encountered the last pixel of the sphere. The remaining scanlines of emptiness would be ignored. When this file is brought into AE, it complains because the file header indicates the resolution to be something like 720 x 486, for example, but the actual data may only cover 720 x 300. When scanline 301 is found missing, things crap out.

mental ray conversely always writes full frame data because it has the full frame in memory at all times (unlike the softimage renderer which only kept what it needed). Therefore, mental ray Zpics will be more reliable.

....I feel old now

Hope this helps,

Matt

---

Matt Lind
Animator / Technical Director
Softimage certified instructor:
Softimage|3D
Softimage|XSI
speye_21@hotmail.com

[gazzmills]

In reply to:
The Zpics coming from the Softimage renderer are slightly different from those made by mental ray.

The old Softimage renderer wrote it's algorithm for Zpics way back in the late 80's/early 90's before the arrival of mental ray. In those days, saving a few bytes of memory meant speed. Remember - a machine with 16MB RAM was considered luxurious in those days. Soooooo, in light of that, the Softimage renderer employed a type of short-ending of Zpic files. That is, no more data will be written to the file after the last object is sampled in the frame. Therefore, if you had a sphere in empty space cenetered in the frame. The softimage renderer would not write any more data to the Zpic file after it encountered the last pixel of the sphere. The remaining scanlines of emptiness would be ignored. When this file is brought into AE, it complains because the file header indicates the resolution to be something like 720 x 486, for example, but the actual data may only cover 720 x 300. When scanline 301 is found missing, things crap out.

mental ray conversely always writes full frame data because it has the full frame in memory at all times (unlike the softimage renderer which only kept what it needed). Therefore, mental ray Zpics will be more reliable.

....I feel old now

Hope this helps,

Matt

-----------------
Matt Lind
Animator / Technical Director
Softimage certified instructor:
Softimage|3D
Softimage|XSI
speye_21@hotmail.com

Thanks a lot for your time and explanation Matt. BTW how old are you, just curious, I'm 29 and sometimes feel old too, hehe, just kidding. talking about changes in hardware, things are going so fast that each year the speed of processors change, i remember when things when changes in computers were a matter of yeras, not months, my old commodore vic 20 and then my brand new commodore 64 ( a whole bunch of 64 K's for ram), great days, but i certainlly like the present a whole lot more,hehe. Thanks again matt.

[zajooo]

In reply to:
I have After Effects 4.0 (for PC), I guess that is too old. I can't find any references to Zpics anywhere.

I'll just make a quick program to read the Zpics and output either 8-bit int, 16-bit int, or 32-bit float monochrome TIFFs. Should be easy enough, and then I can use the TIFFs in any program I need to.

It's in 4.0, but in the production bundle, only.

[atyss]

Sorry for asking an After Effect specific question in this forum, but I searched for this I never found.

I read the post describing the conversion of Zpic floating points files to RGBA files, to achieve greater quality. But could someone please tell me how use those new RGBA files as depth information for the real footage?
Zpics did that automatically, but what about a non-floating point sequence?

Thanks a lot
Bernard Lebel

[hellomojo]

How on earth did Matt Lind know all that stuff about the old soft scanline? Bemused!
al.

[djt0mserv0]

he's a typical newcomer I guess .. ))

In reply to:
How on earth did Matt Lind know all that stuff about the old soft scanline? Bemused!
al.

[ jeva ]

[keirebu-niiru]

Can You explain how to use the motion vector file in shake?

Sanostol