32 bit float exr's from COPs
2913 8 2- chris wells
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- chris wells
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or maybe it just saves out whatever it is given? which if that's the case, how does one process a COP VOP in 32bit float?
I have a height field that I pass it to COPs then use a VOP to put the height data into RGB which at that point it becomes 16bit float. Then when I save that out as a exr, and bring it back into SOPs as a heightfield file, it doesn't match, which means I lost precision at some point. interestingly enough if I just do a heightfile and connect to that VOP and grab the Red channel, it looks fine. so there is something about the exr saver that loses precision. don't know if it's a 16bit thing or what.
I have a height field that I pass it to COPs then use a VOP to put the height data into RGB which at that point it becomes 16bit float. Then when I save that out as a exr, and bring it back into SOPs as a heightfield file, it doesn't match, which means I lost precision at some point. interestingly enough if I just do a heightfile and connect to that VOP and grab the Red channel, it looks fine. so there is something about the exr saver that loses precision. don't know if it's a 16bit thing or what.
- chris wells
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so here is a simple scene, doing what was explained above.
I also brought back the exr and blured it in 16 bit and 32 bit to compare and it's clearly the 16bit causing issues.
I just don't understand how I can connect directly to a 16bit red channel after the VOP and have it look fine,
so for clarity, how can I VOP in 32bit, and if I did would that force the exr saver to write a 32bit exr?
Thanks
I also brought back the exr and blured it in 16 bit and 32 bit to compare and it's clearly the 16bit causing issues.
I just don't understand how I can connect directly to a 16bit red channel after the VOP and have it look fine,
so for clarity, how can I VOP in 32bit, and if I did would that force the exr saver to write a 32bit exr?
Thanks
- jsmack
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The bit depth is set by whichever node is creating the image planes. If you are using the ‘SOP Import’ node, it has a parameter on the image tab “Raster Depth,” which is “Default Depth” by default. This uses the depth of the project, which is 16 bit by default. You can change the project depth (for your scene file) in the Composite project settings. (Edit menu > compositing preferences. or Alt-Shift-I. Or change it just for this node by selecting an alternate depth from the drop down.
It is possible to change depth after an image plane is created, but by this time information will have already been lost.
It is possible to change depth after an image plane is created, but by this time information will have already been lost.
- chris wells
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- jsmack
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If you use a vopcop2generater you can control the bit depth of generated channels. Otherwise, with the vopcop2filter, new channels assume the project default, which can be changed in the compositing preferences. It would seem one would want new channels to have the same depth as the input ones, but here we are.
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