Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: Njen on 2016-07-26, 10:43:32
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Are there plans to implement a bitmap format that is Corona specific? Other renders see speed advantages with custom bitmap formats in areas such as mipmapping and in what order of bits an image is read from disk and how it is accessed.
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There is already: CoronaBitmap, and it's implemented in V 1.3 if I am correctly.
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That's right. We have Corona Bitmap for this.
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I am pretty sure nobody really uses it yet. I haven't see any speed advantage, or better visual clarity. Both 'smooth' and 'fast' filters are kind of... ok. The elliptic from VrayHDRi still has benefit.
It would be useful if it had something 3dsMax Bitmap does not. Like 360 degree mapping, Gamma, some HSL controls, etc. Currently there is no incentive to use it.
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Besides those "xtras" mentioned by Juraj, a "Monochrome" button or tick box would be nice - reducing the need of the ultra slow Color Correction just for this.
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Yeah I don't use it. I'd rather have CoronaHDRI.
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I think Njen referred not to a bitmap loader-I\O plugin\map but to a separate and specifically optimized image format like some of the renderers out there have.
There are already some image formats which are better suited for 3d rendering (or at least better for some specific renderers and some specific scenarios) like uncompressed tiff or some lossless variants of jpeg2000 (which has sadly very limited support) and a couple of others, mainly due to their memory mapped nature, but I'm not exactly sure if Corona utilize that technology or not - Mental ray for example does - http://download.autodesk.com/us/maya/2009help/mr/manual/node20.html or at least did when that was published. + there are some internally mip-mapped\eable image formats but again I'm not sure if Corona can or will utilize that as well as are there any real benefits to that (if any) and aren't there some downsides to those - remember the thing with romullus's "favorite" and rightfully dreaded bitmap proxies )
Again, I'm not totally sure of the benefits and downsides of using those memory mapped formats, though, from my experience, it seems what large, and I mean like REALLY Large res (in my case some terrain satellite imagery of 25000x25000 resolution weighting almost 3.5GBs) in an uncompressed tiff format, used with Corona, rendered a bit faster and 3ds max was generally more responsive with it than with the other compressed and non memory mapped format types I tried using for that same purpose, of course it came with increased memory (both ram and vram) usage during the modelling yet totally or almost the same usage during the rendering itself (which isn't surprising), and it seems that the rendering was starting faster. Still that needs some more thorough testing or even better some explanation\clarification from Corona's team, because I may be exaggerating the benefits and those may only be my wishful thinking or some other sort of placebo effect + that was around 2 or more years ago and I may have simply forgotten that scene's as well of that particular monster of a texture's exact behavior.
So my point would be, such - probably Corona does not need to have it's own image format but instead should be taught to utilize (if it does not already do so) those already present and relatively easily editable ones instead of inventing the wheel anew so to say ). Or maybe I just misunderstood the whole point of the discussion ))
And yeah - here's http://forums.cgsociety.org/showthread.php?f=2&t=607414&page=1&pp=15 some quite old but interesting discussion around and on that particular theme, some of you might find interesting too - there are many speculations but some facts are present as well )
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You're right, it didn't even occur to me.
Imho there is an industry accepted format for memory intensive bitmaps with mipmaping, tiled multiresolution .exr. No reason to reinvent this wheel, there is nothing worse than native stuff that differs from what everyone else uses. I don't know if Corona utilizes it, but Vray does.
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As antanas mentioned, I didn't mean a map type, I meant a format loader type. Reading mipmapped textures are necessary when you have huge amounts of textures to read and want to save on memory. For example, on my current short film I am making, I am at around the 250gb mark so far for textures, and I have more to make.
Not being in front of my computer at home (I'm at work atm), does Corona read mipmapped exr's? what about tx files?
[Edit:] I don't want to turn this thread into a discussion about using smaller textures, I obviously know that's an option to use if necessary. Modern renderers should be able to handle using large amounts of textures. I work in a VFX studio, and some shots I work on sometimes have up to 2tb of textures to read from disk.
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the plan with Corona bitmap was to do these things (mipmapping, out of core, ...), but basically 3ds max API screwed us over big time on this - it turned out there are several places where 3ds Max bitmap node support is hard-coded and other plugins cannot do the same thing (right click menu, popup window for selecting bitmap, copy/paste, ...). So we focused on other things. But we still use the internal part of Corona Bitmap in standalone and Sketchup plugins, so it was not wasted effort
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And there may still come:
CoronaBitmap + rotation controls (degree) + gamma control
https://corona-renderer.com/bugs/view.php?id=1972
And of course the most important part: copy or rename to CoronaHRDI :]
Good Luck
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the plan with Corona bitmap was to do these things (mipmapping, out of core, ...), but basically 3ds max API screwed us over big time on this - it turned out there are several places where 3ds Max bitmap node support is hard-coded and other plugins cannot do the same thing (right click menu, popup window for selecting bitmap, copy/paste, ...).
Some of these obstacles because of Autodesk archaic code are pretty bizarre :- ) It sucks but it does bring some laughs..
And of course the most important part: copy or rename to CoronaHRDI :]
My brain is melted from past caffeine fueled nights, but I hope this is irony :- D The reason why 95perc. of Vray users don't know that VrayHDRi is just extended bitmap loader currently is because they still think it's for 360 HDRi images. So nobody uses it either.
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I hope this is irony :- D
It would at least help to get around a reasonable amount of posts :]
Good Luck
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My brain is melted from past caffeine fueled nights, but I hope this is irony :- D
AFAIK somebody un-ironically requested there to be both CoronaBitmap and CoronaHDRI :D
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In a vaguely related question to my original post to the devs: what are the best performing file attributes when using exrs with Corona?
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Corona de-compresses the file before sampling, so all types of EXR will have the same (maximal) rendering performance when rendering with Corona
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Ahh, right, so any changes in compression would really only affect the read/write speed from disk then I assume.
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at this moment yes
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So, if I understand it right, for now, the only benefit of using big uncompressed/memory mapped format textures (like tiff or exr) is what it can be a little easier for Corona to decompress or do some other similar operations (as I'm too stupid to understand what decompressing means applied to a seemingly uncompressed format)) which Corona does with those before render thus speeding a precalc phase a little at the expense of longer initial texture loading\reading times ?
Also, it would be good to know, which formats and which of their compression\saving modes would be most beneficial in that's the case, well if there are any benefits at all ))
If so, when this tradeoff is surely a thing to consider when using DR especially when many heavy textures are read from some slow non raid and non ssd source ....
And, of course, another question - can we expect Corona to support those memory mapped file format features in the future and are those worth it at all (besides the ability to render something what otherwise simply wouldn't fit in ram) or is there something what prevents you from implementing that, well like sluggish render speeds, some instabilities, bucket only operation possibility or something like that ? I mean in theory it would be a tremendously helpful feature for Corona to have the ability to read those heavy textures directly from hdd when those are needed\seen by rays without the need to keep those in memory all the time.
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Corona de-compresses the file before sampling, so all types of EXR will have the same (maximal) rendering performance when rendering with Corona
is this decompression only for the part of textures that exists on render view or for all of scene textures?
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...
The problem with true out-of-core is that it is SO prohibitely difficult to implement well, that we can make 5 other complex features in the time it would take to implement. With current RAM availability and prices, it makes more sense now to ask customers to bite the bullet and buy more RAM, and offer other helpful features instead (such as multilight, bloom&glare, improved DR, PBR material)
Corona de-compresses the file before sampling, so all types of EXR will have the same (maximal) rendering performance when rendering with Corona
is this decompression only for the part of textures that exists on render view or for all of scene textures?
All of them, there is no easy way to predict what will be visible, and thanks to GI, everything is usually "visible" when considering secondary rays.