Hey - There is not an open mechanism to do that sort of thing right now. If you are willing to look at the source code then the Preview Image attribute is handled in just such a way. I presume that having something like this refactored into an open API would be useful?
- Piotr ________________________________ From: openexr-devel-bounces+pstanczyk=ilm....@nongnu.org [openexr-devel-bounces+pstanczyk=ilm....@nongnu.org] on behalf of Richard Hadsell [hads...@blueskystudios.com] Sent: 17 June 2013 15:33 To: David Aguilar Cc: openexr-devel@nongnu.org Subject: Re: [Openexr-devel] Appending to a partially rendered image On 06/17/2013 06:10 PM, David Aguilar wrote: Not necessarily, but my answer is not strictly an "append" operation. Here's one way that might work. EXR files have a notion of a "dataWindow" which is separate from the display window; they can be different. I'm imagining that you could set the data window to be just the region that does exist; later you can "append" to the image by reading in the current data (as defined by the data window) and filling in the missing regions; eventually the data window will be equal to the display window size, and the image will be complete. This implies that you (or one of the apps you use, e.g. Nuke) is not already using the dataWindow header for something else. The absolute safest thing is to invent your own custom header, e.g. "completedScanlines" or whatever you want to call it, and manage the custom EXR header yourself. Can one modify the header of an output file after opening the file and writing some of the data? I would want to modify the "completedScanLines" attribute after every scanline, before my app has to close or gets killed. I also want to update some other attributes in the header, such as how long it took to render the image so far. -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hads...@blueskystudios.com<mailto:hads...@blueskystudios.com> Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560 Follow Blue Sky Studios on Facebook<http://www.facebook.com/BlueSkyStudios> and Twitter<http://twitter.com/#%21/blueskystudios>
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