iray canvases why only exr
WendyLuvsCatz
Posts: 38,535
I made normal maps using iray canvases but found the main image or beauty or diffuse renders black.
The only solution was to rerender my diffuse map without canvases.
I was rendering the Urban sprawl street layouts as textures for Carrara to use on a plane as the 3delight and iray versions do not work in Carrara.
Is there something wrong with canvases and also why exr format, I converted to jpg with image magicbut tiff or png would be much easier to work with as I do not have many options to use exr or convert.
I added why only exr to the title as apparently they do work if you own photoshop and can read exr properly, this has been confirmed by a friend on Skype
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Comments
It probably only appears black, when you open it in PS you can do HDR Tonemapping (Automatically when converting into 8-Bit) and should be able to see something
I do not have PS only thing I have to convert them is image magic, Gimp even throws an error
EXR output (which is the output from Iray canvases) is 32-bit (HDR). These 32-bit files are tonemapped in the process of converting to them regular old 8-bit files. This can be confusing when encountering it for the first time. I would suggest doing some googling on tonemapping 32-bit HDR images - there's a ton of info out there. Here's a couple links to get you started:
https://en.wikipedia.org/wiki/High-dynamic-range_imaging
https://en.wikipedia.org/wiki/Tone_mapping
- Greg
well not owning Photoshop its kinda useless to me then, I might just have to use Octane for the other canvases instead, is faster and gives a useable result, I really only needed the diffuse to be in either iray or the 3Delight one for the proceedural shaders, the normal map was for projecting the 3D shape on a plane with that diffuse.
what iray gives me converted with image magic
what Octane gives me
in any format I chose
what Carrara gives me
also in png, tiff, jpg, bmp, tga and psd for that matter
obviously some blank as elements being selected for render not present but still iray seems to be rather lacking???
this is what I can get from Octane render for Carrara
again in a multitude of image formats
so I am still trying to get my head around how exr is better than the choice of formats the other three offer that all programs even Microsoft paint open
None of this has anything to do with EXR as a file format. It's just a way to represent 32-bit data; it's like a compressed TIF, but with 32-bits per color, rather than 8-bits per color.
The differences you are seeing are based on the canvases that Iray produces, which are controlled by its default light path expressions (LPE) feature. These are mostly intended for use as post work layers, and in facy may be assumed for Photoshop over any other image tool. If you're adventurous, you can alter the LPE to create custom canvases. Not sure you'll get what you're looking for, but the functionality is there to do so.
the point being image magic the only free option I can find to read and convert exr misses all this information
I can no doubt get all those other maps if I owned photoshop but would it not be simpler if like Octane and Carrara iray just gave the option to save as png etc too?
Have you looked at the capabilities of Black Magic Fusion or AutoDesk composite, both I believe free? There's also Natron, and I think there's a PLE version of Nuke now. Any of those should be able to handle .exr files.
The beta for the next version of GIMP includes EXR support, if you don't mind using a beta.
IrfanView can read and save .exr files in different formats, it is also free.
I have not been able to make it work. Same response as Gimp 2.8. Did you manage to open .exr files with Gimp?
D|S already saves the rendered canvas as a PNG, JPG, or TIF. You save this image, and THEN the EXR is automatically created. But these other formats are 8-bit, not 32-bit. Since you're only seeing a quarter of the tonal map, the useful information may be outside the mapped range you need. D|S and other the tools may differ here in which 8 bits are being saved -- top bits, bottom bits, or some place in the middle. I would recommended a tool that opens EXRs (e.g. the ones noted in this thread), but you might also have some success by fiddling with the various tone mapping settings (including the blacks and whites thresholds). That to me seems like a lot of work for any benefit you might get, but it's worth a try.
I have not used the beta for GIMP -- I have Photoshop. But at least one poster in the forums seems to use it for this, don't remember name
I have tried without success using irfanview, I added the plugin but get blank images
Blender will open them but honestly its more trouble than its worth, I am glad I have Octane render and its DS plugin, I mostly want the normal maps and interestingly can get an image from the iray exr for that but it's odd coloured so use the Octane one instead.
What I am doing is rendering out iray procedurals on surfaces for retexturing in other apps and renderers mostly Octane and iClone and Carrara.
Often they are geometry based too so re-uv mapping the item required for my created map, flat mapped from above like the render.
the 3Delight procedurals present similar issues but know I cannot get canvases from that and cannot figure out texture baking from a procedural which actually would solve everything.
Texture baking is what I do in Carrara with Inagoni baker if using a procedural like a terrain shader, if only DS could do that with iray or 3Delight even it would solve everything.
Its a shame so much DAZ content is DS iray only now, exporting untextured obj pretty useless in many cases.
And thanks Richard, I do have Fusion if I could figure out how to actually export from it.
OK I solved it
or rather learnt how to in Blender sequence
simply import images by selecting add browse and hold [a] to add them all as a sequence then under anim do sequence and in format pick one you want and hit render