Reality renders taking forever

Some months ago, I purchased the reality 2.0/luxrender package. Fired it up once and just thought it was way over my head since I had used to ol' point and click firefly and 3Delight renderers. So, today, thought I'd take it for a test drive since I've educated myself in the actual nuts and bolts of renderers a bit. What I'd like to know is it common for a basic 1-light portrait/head-shot render, 1584x2000 pixels to take 28 HOURS to render? I'm looking for about 500 pixel samples before I shut the renderer down and it's taking about 2 minutes per pixel sample. From what I can tell from the status bar, I'm running between 10 and 14k samples/sec. I'd really like to re-render a few of my favorite scenes with reality but at that speed, it'll take me weeks for just a few renders. Any help for speeding up reality/lux would be much appreciated.

Comments

  • frank0314frank0314 Posts: 8,582
    edited December 1969

    The image will keep rendering until you hit stop.

  • AelfricAelfric Posts: 0
    edited December 1969

    Reality, or more correctly the Lux render engine, never finishes a render, because that isn’t the way it’s designed to work.

    Lux starts by rendering a very rough approximation of the scene. It then refines the render to produce a more refined image, and keeps refining and improving the render until you tell it to stop. Watch the image, and when you’re happy with the result and can’t see the incremental changes, stop the render.

  • LoaarLoaar Posts: 0
    edited December 1969

    Without your system specs it is hard to judge if its being slow or if your computer is dragging it down.


    Reality (Lux) is significantly slower (in my experience) than for high quality stuff than the native render engines in DAZ/Poser though, thats the trade off for the more realistic images.

  • Richard HaseltineRichard Haseltine Posts: 19,316
    edited December 1969

    500 samples/pixel should give adequate, or even good, quality - if it isn't, is you scene enclosed in a room or environment that might be blocking the light?

  • FirstBastionFirstBastion Posts: 2,366
    edited December 1969

    we need more information like the system specs and and maybe the image itself.

  • larsmidnattlarsmidnatt Posts: 2,747
    edited June 2012

    Also 30 hours to render is not that long frankly. You can always cut the resolution down if you only intend to use the image on the internet. If you cut the resolution in half, 700x1000 it would take approximately 7 hours (based on your initial statement 28).


    There are people who let there renders run for weeks, it depends on your system specs and how many samples the image really needs.


    I often have to leave mine running till they hit 1k S/P or more.


    one thing I have not figured out is why some renders take longer than others even though they seem like they should be about the same setup. I had one render take 40 hours, while another scene with similar setup took 8. Once I figure out the variable I'll be a happy camper.


    If you have other computers on your network that can contribute to the render I would do that. Lux lets you add other machines to the cluster, so you can save time there. The hold up will be ram, each machine will need to have enough ram to hold the scene otherwise it won't work. By adding a second machine I cut my render times in half. So that 40 hour render was originally 80 hours for something that was 2400x3600 or so.

    Post edited by larsmidnatt on
  • FirstBastionFirstBastion Posts: 2,366
    edited December 1969

    I believe Paulo said that Lux calculates everything in a scene including what is not visible within the frame of the render. Render times will speed up, if you remove or make invisible anything that is not in the "shot" . Also glossy surfaces take longer to render than matte.

  • BobvanBobvan Posts: 1,425
    edited December 1969

    Hiding unseen things body parts and grouping lights dont really do much IMO. Its all depending on whats in the scene. I have been at it for 3 months 200 plus renders. I get anywhere from 40 minutes to 3 days. I have discovered what seems to eat alot of time is a large amount of lighting. Do keep in mind that new new LUXRC's seem to render alot faster..

  • MrugnakMrugnak Posts: 272
    edited December 1969

    I would also recommend experimenting with the hardware rendering option if you have the video card for it. You don't have access to all the surface options if you do pure-hardware rendering, but with a good videocard it's quite fast.

    Hybrid hardware-software mode can improve performance in scenes with lots of glossy surfaces, but will reduce performance in simpler scenes due to the extra overhead of co-ordinating the two systems.

  • larsmidnattlarsmidnatt Posts: 2,747
    edited June 2012

    Bobvan said:
    Do keep in mind that new new LUXRC's seem to render alot faster..

    I think I have noticed about a 50% increase in speed as well with the most recent RC, really impressive.

    Post edited by larsmidnatt on
  • BobvanBobvan Posts: 1,425
    edited June 2012

    I find I get much superior results with LUX. I dont modify maps and such. I switched to LUX was because I could not be bothered with tweaking too much stuff. Its kind of like with a computer. Some will overclock modify motherboards ect. I Just want to set up and render. The film response and settings in LUX work really well. And finally for stuff that will not play nice in LUX.. PS is your friend...

    OT Im finally starting to get LUX commission project for which I can now charge more for more time invested..

    Post edited by Bobvan on
  • edited December 1969

    OKay.. machine-wise.. I know I'm a tad slight in the ram department.

    It's a quad core amd phenom 9600 gt running at 2.3mhz, 8 gig of ram(can't do anything about it until october).
    As far as letting renders go forever.. just can't do that at this time either.. need the machine for school which involves other 3D rendering at times. Since originally posting this, I've had some pretty amazing results with SLG. I've also talked a bit and harvested tidbits of information here and there. One thing that was slowing my renders waaaaaaaaaaaaaay down was having DazStudio lights in my scenes. I've taken them out with better results.

    Where I've decided most of my roadblock is is more mental than anything and a product of my artistic past. I started out in the irc-based magazine scanning community. Mainly on the dalnet channel #SDC for those who may know of the irc community. The way you work with magazine scanning is to scan huge, do your post work and then reduce image size to tighten up the image. It wasn't unusual for me to scan at 900 dpi which creates an image well over 7000 pixels high for a full page scan and then gradually reduce down to 72 dpi which makes a respectable 1024x768 shot. I still have(had) that mentality with rendering. Render huge and reduce in postwork. That isn't needed with most renderers and specially not Lux. I have to put it in my mind to render at what I want the final size to be or just a wee bit larger. This would greatly reduce my render time but it's hard to overcome as I'm used to looking at really high quality pics that are like 3000 pixels on the longest side.

    On the lux side. I've downloaded the 1.0rc version and installed it but reality still is telling me that it's 0.9 and I can't seem to find out what the issue is. I've even installed it in a separate folder and pointed reality to the new folder. I'm using reality 2.0 and can't do much about upgrading to 2.2 until October either. All my rendering product was provided by my now-former employer and I don't have the info to get the free upgrade to 2.2. Fortunately enough, content-wise I was able to walk away with all the product that I had purchased for the company going clear back to '06.. which if my math is correct equals up to the cost of a new Corvette with all the options.

    Haven't had the time to render with Lux after harvesting the new info that I have in the last 24 hours; but, I'll post the results later when I have something to show for my work.

  • larsmidnattlarsmidnatt Posts: 2,747
    edited December 1969

    I only have 8 gigs of ram and I make it work, but then again I know I can't render higher than about 4000k pixels in a single dimension. usually renders start off eating around 4g and slow go up from there. Haven't had a problem though. I do want 16gigs, but I can't really do that at the moment so I just work around it.

    And a lot of my scenes end up only needing 2gigs of ram and occasionally less (a pinup for example).

    Glad you got rid of the daz lights :)

  • MRICEY1980MRICEY1980 Posts: 0
    edited December 1969

    Just obtained LUX and bought the poser 3 reality plug in

    As with most people I'm pretty efficient with Firefly and D/S renderer
    This however is a whole new ball of wax..

    My Sys spec is the following >

    Windows 7 Home edition 64 bit
    AMD Bulldozer 6200 6 core processor clocked at 4.2 GHZ
    16 Gb DD3 Ram 1333 speed
    1 Terabyte HDD
    250GB SSD

    and my GPU is a Radeon 7770 1 GB DDR 5 card

    Am i going to have issues running this software..?

    Many thanks

    Platinum x

  • StratDragonStratDragon Posts: 1,746
    edited December 2013

    Just obtained LUX and bought the poser 3 reality plug in

    As with most people I'm pretty efficient with Firefly and D/S renderer
    This however is a whole new ball of wax..

    My Sys spec is the following >

    Windows 7 Home edition 64 bit
    AMD Bulldozer 6200 6 core processor clocked at 4.2 GHZ
    16 Gb DD3 Ram 1333 speed
    1 Terabyte HDD
    250GB SSD

    and my GPU is a Radeon 7770 1 GB DDR 5 card

    Am i going to have issues running this software..?

    Many thanks

    Platinum x

    nope, you're fine. just start working small and remember your not rendering in 3Delight, it's different behavior altogether.
    LuxRender is more of a reality based (the physical workings of it, not the software package with the same name) approach to rendering, especially when it comes to lighting. if there is a specific something you're trying to find out you can also ask in the LuxRender forums
    http://www.luxrender.net/forum/

    Post edited by StratDragon on
  • Herald of FireHerald of Fire Posts: 3,359
    edited December 1969

    The biggest contributors to long render times are reflections. If you have high amounts of specular on a lot of surfaces, it takes longer for individual light beams to be 'destroyed', since they're just bounced around the scene while yet more photons are created. For that reason, enclosed areas aren't ideal, and you should avoid creating 'perfect' mirrors that face each other. By 'perfect mirror' I mean materials which reflect 100% of the light and absorb nothing. The mirror material in Luxus/Reality is designed to absorb a small amount of light as real mirrors do.

    Off-screen geometry is calculated even if it's not visible. That means that if you have a particularly large amount of off-screen scenery or figures it's as good as zooming out and rendering everything on screen, since it will still calculate the light for those polygons and shaders whether it's visible or not, due to it being an unbiased renderer. For that reason, hiding items not in the frame will significantly impact render times overall. Of course, if the item in question is casting a shadow visible in the final render, then keep it visible, but make the material into a matte to minimize light bounce.

    Too much light bounce is also the primary cause for fireflies, so it's best to tackle problems at the root.

  • VanguardVanguard Posts: 457
    edited December 1969

    And to address the "I don't have time to let a render run" scenario, one big plus to using LuxRender is that you can pause the render and continue later. Or stop it completely and resume the render later. Thus letting it render while you are AFK, for example.

  • StratDragonStratDragon Posts: 1,746
    edited December 1969

    Vanguard said:
    And to address the "I don't have time to let a render run" scenario, one big plus to using LuxRender is that you can pause the render and continue later. Or stop it completely and resume the render later. Thus letting it render while you are AFK, for example.

    you can also turn down the core utilization and split your CPU to render and continue modeling, surfing, etc. with what you left over right from the Lux Interface.

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