OpenEXR filesΒΆ

Multi view

If multiple AOVs have the same filename, those images will be stored in the same file. This multi view image output is only available with the OpenEXR format.

You can define how images are named in the file by specifying a name pattern in the Render Settings > File > Layer Pattern property of the RenderPass. The Layer Patterns use the same specifiers as the File Pattern, such as $l, $n, and so on. If left blank, Guerilla will use the OpenEXR specification as follow. Let's say we have a layer with two AOVs, Beauty and Z, in stereo, with the File Pattern $05f.exr at frame 10. Guerilla will write the file 00010.exr with the following channels:

R
G
B
A
Beauty.right.R
Beauty.right.G
Beauty.right.B
Beauty.right.A
Z.left.R
Z.left.G
Z.left.B
Z.left.A
Z.right.R
Z.right.G
Z.right.B
Z.right.A

According to the OpenEXR recommandations, the first AOV is not prefixed by "Beauty.left.".

Channel vs Multi-parts

You can choose to store your layers and AOVs in channels (OpenEXR 1.0) or parts (OpenEXR 2.0). To store them in parts, check the "RenderPass -> File -> Multi Part" or the "AOV -> Multi Part" attributes.

Deep Images

Guerilla Render can render deep images. Those images must be written in OpenEXR 2.0 files. Those files are written in multi parts.

All the pixel filters are available using deep images.

Deep images are heavy on disk. To reduce their weight, it is possible to compress the deep pixels with a lossy compression using the "RenderPass -> File -> Deep Compression" or the "AOV -> Deep Compression" attributes.

  • 0 : no compression (lossless deep image)
  • 0.1 : a conservative deep image
  • 0.9 : a light deep image
  • 1 : maximum compression

The flatten image is always lossless, whatever the Deep Compression attribute. Only the deep image may loose some informations because of the deep compression.

Deep images are always in gamma 1.0, whatever the Gamma attribute.

Data window

By default, Guerilla writes the EXR files with the minimal data window. This data window is used by the compositing softwares to detect the empty part of the image. It has been reported that some Adobe products may fail to read such EXR files. In that case, uncheck the Properties -> Rendering -> Write EXR Data Window local attribute on every computers rendering EXR files.