Custom Made MultiChannel OpenEXR

By Louis Marcoux - 12 Jan, 2010

In this tutorial, i take a deeper look at the new Multi Channel OpenEXR file I/O in order to combine multiple bitmaps into a single Open EXR file. This tutorial is an extended version of a tip i gave in my tips and tricks webinar on January 13th.

You can view the webinar by visiting the Autodesk Entertainment Center here.

The Connection Extension features discussed in the video can be viewed here.

Part 1 : Multi Channel Open EXR Workflow

The first video is an overview at the basic functionality of the new Multi Channel Open EXR I/O in 3ds Max.

Part 2 : Mental Ray Labeled Element

In this video, i will show you how the Mental Ray Labeled Element can be added to the render elements in order to capture any aspect of a material as a render element. That setup will be useful to define what we want to put in the Multi Channel OpenEXR.

Part 3: Camera Map per Pixel

Here, we will look at the technique used by matte painters to project an image from a camera point of view. This is useful to have matte paintings with few 3D objects that offers perspective even if it's for a matte background. This tool will be useful for rendering bitmaps full frame without bothering with the UV mapping of the objects in front of the camera.

Part 4: Final Setup for Combining Material Components

Here, we will use all the tools we have seen so far to create a setup that will allow us to combine multiple aspects of a material into a single Mutli Channel Open EXR file.

Part 5: Stereoscopic Multi Channel Open EXR

For this final video, we will review our setup to create a basic left and right Multi Channel Open EXR file from 2 image sequences. We will also optimize the render time by turning off what we don't need in our setup. And, we'll setup the file for quick access to the bitmaps when the file is opened and used for Multi Channel Open EXR generation.

 

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Pochaal | 7 years ago
Never Mind I have instaled Autodesk Connection Extension. Bump question soved Thanks a lot, anyway. Regard Alexandre
Edited by Pochaal 7 years ago
Pochaal | 7 years ago
Hi, Marcoux I love working with Openexr file on my composition projects. It's amazing and flexible. But, I have been facing a problem with my 3D Max Openexr when saving. Because the configuration of the openexr doesn't allow me to select passes like diffuse or specularity. I have noteced that it is the version 1.2, and I think that maybe this problem is caused because I do not have a earlier version of this app. How could I instal a new version of the openexr on my computer to have all the configuration available? Thanks, anyway regards Alexandre
Edited by Pochaal 7 years ago
Pochaal | 7 years ago
Hi, Marcoux I love working with Openexr file on my composition projects. It's amazing and flexible. But, I have been facing a problem with my 3D Max Openexr when saving. Because the configuration of the openexr doesn't allow me to select passes like diffuse or specularity. I have noteced that it is the version 1.2, and I think that maybe this problem is caused because I do not have a earlier version of this app. How could I instal a new version of the openexr on my computer to have all the configuration available? Thanks, anyway regards Alexandre
Edited by Pochaal 7 years ago
metalrahul | 7 years ago
Somebody really has to do a extensive tutorial on camera map per pixel map showing its full capability. I was also wondering is there any way to do multiple camera projection inside Max?
SuperCoon | 7 years ago
As of yet I have still not been able to use or explore the open EXR file format, so I was wondering if anyone could point me in the right direction for research. Basically, stuff like what was the advantage of packing the "Diffuse", "Bump", & "Specular" (as demonstrated in this tutorial) into one open EXR file format? I understand a good deal about the HDRI file format, & I've been told that EXR is very similar; although, I think there is a lot more to the EXR format than I understand about HDRI. Either way, I would be very grateful if someone could point me in the right direction for research.
SuperCoon | 7 years ago
Thanks Louis, I was able to watch the link today. The "Tips & Tricks" was very nice, & it leaves me with a couple of questions: First, is it possible that you may one day do a quick video tutorial on "Match Mover"? Match Mover seemed fairly simple & straight forward, but I would love to have one of your video tutorials to refer back to. Second, has anyone been able to figure out why the "Connection Extension" has been causing the broken "Snaps" issue within Max? I would really love to get the full use (mainly open EXR) out of my subscription by using the "Connection Extension", but to date I have had to keep it removed from Max because I really so heavily on the axis constrained snap feature for my work load. Either way, I understand if you do not have an answer for me; however, as one can see in the links I provide within this thread the issue is fairly old, & a bug report was submitted some time ago by myself & my reseller. Once again, I would not hold you responsible... :) Over all, truly great work, & I come to find myself following your tutorials rather closely; keep up the good work.
Louis Marcoux | 7 years ago
It should be up soon. They told me it would be up by last week but maybe they ran into some issues with the compression. It should be there within a few days... But it will be posted, no doubt. It's in the process... Sorry for the delay... That part is out of my control...
SuperCoon | 7 years ago
It appears the link (not the link on this page, but at the actual source) is still broken to the "Autodesk 3ds Max Tips & Tricks - January 13" web cast; any idea as to when it might become available?
Swahn_Kung | 7 years ago
Shane Bekker, depends on what you are referring to. Camera projection is no problem. You can combine the Camera Map Per Pixel with a Camera Map (WSM) on the object in question to get interactive feedback on the texture projection. Keep in mind that it must be the (WSM) version wich is a World Space Modifier. That means it takes in account the dependencies outside the node wich it is being applied to, like if the camera move (camera belongs to an outside node) then the projection updates accordingly because it knows dependent objects have been changed. As a side note, if you are dealing with texture that uses different resolution than the render output you have to scale the projection camera in X and Y respectively if you want to maintain aspect on the texture. Use Camera Scale / (renderSize/textureSize) to calculate the correct values. It's easily made using the Numerical Expression Evaluator. The scale should be entered as '100' (as in 100%), while if you manipulate using script a scale of 100% is expressed as 1.
Edited by Swahn_Kung 7 years ago
Shane Bekker | 7 years ago
Hope this is not far from the topic but can one do this? http://greyscalegorilla.com/blog/2010/01/camera-projection-in-cinema-4d-part-1/
SuperCoon | 7 years ago
Thanks. I really hope they can get the Connection Extension & Max's UI in sync; it's really annoying. For me I had to uninstall it because I use my snaps so heavily at work, & that limits me to being exposed to some of Max's new features; either way, I'm grateful you passed it on. Thanks for the information on the link, & keep up the good work... :)
Louis Marcoux | 7 years ago
Oh. And the link of the webinar will work later this week. They have recorded the session and will encode it so that it becomes available. It takes a few days after the webinar is done before it shows on the page.
Louis Marcoux | 7 years ago
Hello DMAXMAN, i have pointed our testing and R&D team to the links you gave me. It's worth investigating.
SuperCoon | 7 years ago
One last comment: It is worthy to note that when I uninstalled the "Connection Extension" all parts of Max's UI went back to working normally.
SuperCoon | 7 years ago
Once again some awesome insight, but I've come to expect nothing less from you... :) Anyway, I could not get the "Tips & Tricks" webinar link to work, any ideas? In regards to the "Connection Extension" I have a question that you may be able to answer. Back when the extension came out I installed it & starting exploring some of its features; however, it broke some parts of Max's UI; in particular, it broke my snap settings in within Max. The below listed links will point you to the topics on the Area, but at this time the issue has not been resolved; at least not to my knowledge. http://area.autodesk.com/forum/autodesk-3ds-max/autodesk-3ds-max--3ds-max-design-2010/connection-extension---snaps http://area.autodesk.com/forum/autodesk-3ds-max/autodesk-3ds-max--3ds-max-design-2010/snap-settings-icons-shuffled I filled out a bug report on this issue, but nothing never came of it; likewise, my software vendor contacted Autodesk in regards to this issue & Autodesk confirmed the problem. Have you got any ideas on how to fix this?
Louis Marcoux | 7 years ago
I agree with you Swahn Kung. This workflow was more of a good excuse to show the flexibility of the Open EXR I/O with the Mental Ray Labeled Element. I wanted to find a way to show how far you can go with this and i thought that this approach was good subject. Once the scene is done and saved, you can always call it back to combine multiple channels and you don't have to go through the whole process again to set it up... I use it for stereo shots that i have rendered with my StereoCam script. If you want to combine multiple images into a single Open EXR file, there is also a plugin for Photoshop: http://www.fnordware.com/ProEXR/. I have never tried it but i know it exists. For the buckets size, you are right about time saving. But, in the case of a single plane with only a few vertices to define the geometry, the access to the scene database is not that demanding so it doesn't affect final render time that much. But in the case of a scene with more objects that fits in RAM, i fully agree that it would save time. Reading a scene database for every bucket can take time if the scene is more complex. That would be a good tips and tricks subject right there! :)
Swahn_Kung | 7 years ago
That's some clever workarounds, feels a bit clumsy though. Some minimal tool with sleek frontend would be prefereable ofcourse. And hey, speaking of render optimizations, try adjusting bucket size when rendering simple projected bitmaps. If you find balance between load and memory you can save minutes on each sequence you render. Too small buckets will create a bottle neck were the CPU isn't supplied with enough information fast enough to work optimally. Too large buckets will be too much information for the CPU to process and you get lower performance as well. Your optimal bucket size vary depending on how much RAM and CPU you have ofcourse, and if you don't care to optimize such renders, too big or too small buckets won't make it crasch anyway.