my first post: need very very basic help with iray please

hi all, this is my very first post here.

I have a laptop with 4 gb ram and a geforce 820m with 1 gb video ram. I can't get iray to use my video card. If I set cpu then it renders, but if I set GPU 820M it quits without even starting rendering and leaves me with an empty image.

Now I know that there are memory limits to render with GPU but I can't even render a simple vase with no textures ! So I guess this is not a memory issue.

What I need is a very simple scene that I can load and render using iray just to test if iray works with the GPU. A simple sphere would do the job. Could any of you please provide a very simple scene ready for iray that I just have to render ?

thank you for any help

Comments

  • ChoholeChohole Posts: 33,604

    AFAIK you need a more powerful GPU before Iray will use it.   More cuda cores and more on board memory.   That is quite an old, low power card.

  • PadonePadone Posts: 3,700

    thank you very much for your reply

    are you sure ? so I can't even render a simple cube with my card ? what are the minimum requirements for iray to render a simple cube then ?

    I can use Blender and it works fine with my 96 cuda cores. But I would like to give iray a try. But if you say it has min reqs for card ok. It just seems odd to me that I can't even render a simple cube.

  • ChoholeChohole Posts: 33,604
    edited August 2015

    This is a thread where people are posting their benchmakrs on a starter scene   http://www.daz3d.com/forums/discussion/53771/iray-starter-scene-post-your-benchmarks/p1

     

    I think DAZ 3D are recommending 4gb ram on the gpu

     

    Another thread here about choosing a video card   http://www.daz3d.com/forums/discussion/56583/choosing-a-new-nvidia-card-for-iray-rendering/p1

    Post edited by Chohole on
  • PadonePadone Posts: 3,700

    thank you very much for your reply

    I downloaded the scene but there's something odd. That scene doesn't even render with cpu. That is, the iray engine runs since I get iterations going on 1,2 .. 10 etc. But the rendering stills a black screen.

    I can render other daz scenes. For example the barefoot dancer in the beginner tutorial goes well with iray cpu rendering. Though it doesn't work with GPU. But the bechmark scene you pointed to me doesn't render stills a black screen. I deleted spheres 8 and 9 as suggested in the benchmark post.

    Anyway .. thank you for your help very appreciated. I'll try to find or build a simpler scene to do my tests .. Anyway at least I can use the cpu (but not with the benchmark) .. bye and thank you again

  • PadonePadone Posts: 3,700

    update

    Well if I use photoreal mode then everything works fine I can render with iray cpu. The scene just doesn't work with interactive mode dunno why. Still doesn't work with GPU. What makes me wondering is why DS doesn't give me some error message or anything .. If I choose GPU it just says "finished rendering" and exits with a black screen. Could say not enought memory .. or card unsupported .. or anything ..

    well .. I'll go on with tests and see ..

     

  • MelanieLMelanieL Posts: 7,384
    edited August 2015

    Question 1 - I presume your video card is showing up in the Advanced settings in the Render tab? Mine failed to show up at first because my drivers were out of date.

    Question 2 - If the card is showing up, did you select both CPU and your video card to do the render? If so, then even if the card is inadequate the render should automatically switch to use CPU.

    Question 3 - Are you sure you're not getting any error messages earlier in the Log file? For example I get these messages in the log file on my laptop (it's drivers are no good):

    "WARNING: dzneuraymgr.cpp(256): Iray WARNING - module:category(IRAY:RENDER):   1.1   IRAY   rend warn : Failed to determine NVIDIA CUDA driver version; iray can only run in CPU mode. Please update your NVIDIA driver (www.nvidia.com)."    then further down:

    "NVidia Iray GPUs:
     GPU: 1 -
     Memory Size: -1 bytes
     Clock Rate: -1 KH
     Multi Processor Count: -1
     Cuda Version: NA
    WARNING: dzneuraymgr.cpp(256): Iray WARNING - module:category(IRAY:RENDER):   1.0   IRAY   rend warn : There is no GPU available to the iray renderer."

    This all appears during DAZ Studio initialisation, before even loading anything into the scene.

    Since I updated the drivers on my main rendering machine, I can render small scenes perfectly well with my 2GB video card, but maybe 1 GB is just too little - for example I just loaded a primitive sphere and added an Iray carpaint shader to it, set draw dome to "on" (using the simple HDRI that comes with DAZ Studio) and rendered to GPU and 1158 MB of my GPU memory was being used in total (it's also running my monitor and anything else a video card normally does)

    Post edited by MelanieL on
  • ToborTobor Posts: 2,300

    D|S does give you feedback/errors/warnings. Go to Help->Troubleshooting, then choose the log. Scroll down to the end and it'll tell you what happened during the last render.

    Though the 820M supports CUDA, and Compute Level 2.1 (the minimum is 2.0) if it's the only video card in the system, it has to hold the memory for your screen, as well as the rendered scene. There might not be anough RAM for even a simple one object render.

    You can create your own simple scene by choosing File->New, and adding a new primitive -- Create->New Primitive. Choose Cube. Render, and when it's done, check the log. Any errors that prevented GPU rendering will be shown.

    As Melanie points out, you must be using a fairly recently driver. If it's older than about spring of this year, it may not work.

  • PadonePadone Posts: 3,700
    edited August 2015

    Melanie, Tobor, thank you very much ! You did catch what the problem is !! I didn't know there's a log before .. if I go to help > troubleshooting then the log says:

    IRAY   rend info : NVIDIA display driver version: 33343
    IRAY   rend warn : Failed to determine NVIDIA CUDA driver version;
    IRAY   rend warn : GPU 1 (GeForce 820M) with CUDA compute capability -1.-1 cannot be used by iray.
    IRAY   rend warn : There is no GPU available to the iray renderer.

     

    Then i updated both my intel hd and nvidia driver and now the log says:

    IRAY   rend info : NVIDIA display driver version: 35560
    IRAY   rend info : Your NVIDIA driver supports CUDA version up to 7050; iray requires CUDA version 6050; all is good.
    IRAY   rend info : CUDA device 0: "GeForce 820M" (compute capability 2.1, 1024MB total, 966MB available)

     

    Now everything works fine and I have to say iray is pretty impressive .. I can use the intel hd as viewport renderer so to leave 1G ram for iray and maximize performances. I already do this with Blender and it seems it works with DS too.

    Thank you again very much you guys .. err .. and ladies cheeky bye

    Post edited by Padone on
  • MelanieLMelanieL Posts: 7,384

    Glad to hear you got it working. Enjoy!

  • PadonePadone Posts: 3,700
    edited August 2015

    Tests are excellent ..

    Despite my low-end laptop I can render a complete dressed character in just some minutes ! A scene takes just a bit longer but usually needs less convergence because human eyes are less sensible to scene details than to character details .. The only limit I have is I can't render characters and scene together because it takes way too long. I guess not enought memory and/or computing power to do so .. Anyway I can render scene plates alone and then compose characters on them. This also has the advantage that scene plates can be reused without having to render them again.

    Below is a simple composition from the barefoot dancer tutorial. Character took 4 minutes to render, scene plate took 5 minutes. I composed them together with gimp afterward .. no filters used just plain rendering .. HW specs N2840 4G ram geforce 820M 1G ram .. very low profile hw cheeky

     

    dancer_03.png
    500 x 650 - 740K
    Post edited by Padone on
  • PadonePadone Posts: 3,700

    update

    well I found these two little cuties cuda-z and gpu-z that are simply amazing .. cuda-z tells you everything about your cuda capabilities, so if you have any doubt about specs this is the way to go .. gpu-z is even more amazing, since you can keep it open while DS is rendering and it tells you how much gpu power and video ram is used !! perfect for monitoring iray ..

    so just rendering and watching I discovered some facts

    - nude G2F takes about 190 Mb in video ram, while dressed takes about 250 Mb

    - the bf dancer scene takes about 500 Mb in video ram

    So it is not true that I can't take both of them at the same time as I supposed before. The fact that it is slow to render doesn't come from lack of memory. I guess when a character is inside an environment then iray has much more calculations to do that's all. While rendering the scene separated from the character simplifies calculations and thus iray is faster.

    If anyone has some experience with memory and gpu optimizations in iray I'd love to learn anything .. smiley

     

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