A couple Newbie questions about lighting, rendering setting, and system optimumization.

cdemeritcdemerit Posts: 505

First, I'd like to say, I wasn't sure if I should post this here or in the new user area...

I'm fairly new to Daz, and am still learning a lot, and have a lot to learn. I have a couple questions, that are related about lighting, and what happened.

This is my base image: http://i.imgur.com/ciR1fYf.png one of my characters in bed. I know there are some posing issues, but it was a quick (or so I thought) lighting test, so I wasn't worried about pose. I didn't use any lights with this image. I like the look for the most part, but would like to see some shadows. render time about 45 sec.

This is the same image, but using UberEnviroment2 light preset: http://i.imgur.com/SxdLNPd.png I get some shadows, but I also get a grainy squares in the render, that almost look like the UV map is bleeding through. I'm sure I had to do something to cause this. any thoughts? render time: about 3 minutes.

and finally I tried the "bright moonlight" preset: http://i.imgur.com/YZD59Fx.png The first attempt to render took 10 minutes to get to 20%, 10 more minutes to get to 26%, and stalled there, at 26% for almost 1 hr before I cancelled the render. (had to reboot the computer too.) I deleted one of the 4 lights in the preset, and tried again. as you can see it worked, but it took 1hr 30 mins to render. I like the look, but I don't need so much detail, at least not if it is going to take 90 minutes to render each time.

All renders used the 3Delight engine, and the only settings that changed were the lights. My computer is not optimal for 3d work, but I'm in no position to upgrade it. During the render I was watching system resources, my CPU was pegged, but I was only at 60% physical memory. I had closed out any non-essential programs/processes during the render) running windows 7 64bit, with 6GB ram and a 2.8 ghz processor.

So my questions are:
what happened in image 2 to cause the graininess in the render?
What render settings can I change to reduce the detail in the render (in the hopes of speeding the render)?
is there any way I can move some processes to help take the stress of my weak processor?

Comments

  • LinwellyLinwelly Posts: 5,946
    edited December 1969

    unfortunately I'm not able to explain the fenomenon to you but at the same situation for several times when I added an Uberenvironment light. So It seems to me the cause really is the uberenvironment. In my last render I somehow bypassed the problem even though I used the Uberenvironment light. I'm not yet sure what I made different this time.
    Hope to get reason an wa way to avoid this as well, so good luck

  • GarrettDRGarrettDR Posts: 229
    edited December 1969

    Some thoughts:
    1) The 'grainy' look
    https://www.youtube.com/watch?v=AlKMMeTY3h8

    2) Render settings
    http://www.daz3d.com/forums/discussion/16085/

    3) I don't think so, depending on your computer specs, the more you put into an image, lights, shaders, objects, size, etc. the more it is going to ask of your pc.

  • Scott LivingstonScott Livingston Posts: 4,340
    edited December 1969

    There is often a tradeoff between speed and render quality: the quicker an image renders, the lower the quality; the nicer it looks, the longer it will take. This isn't an absolute rule, and there are ways to make things go much faster without sacrificing much quality, or ways to improve the quality without slowing it down too much, but these tricks depend on a lot of different conditions.

    For UberEnvironment2, I'd recommend looking through this thread: http://www.daz3d.com/forums/discussion/5320/
    It's a complex topic, but a very powerful and important thing to learn.

    The short answer to how to improve image #2 is Shading Rate. You may need to lower the shading rate of the UberEnvironment2 itself, or the overall render shading rate, or both. Here's how you find these settings:
    - UE2 shading rate can be found by selecting UberEnvironment2 in the Scene pane and then going to either the Parameters pane or Lighting pane
    - overall shading rate can be found on the Render Settings pane

    For UE2, I generally use a shading rate of anywhere between 8.00 and 2.00 (lower is better, but takes longer to render), depending on the scene, what other lights I am using, etc.

    For overall shading rate, I use anywhere from 0.1 to 1.00...most of the time I use 0.20. Again, lower is better quality.

  • cdemeritcdemerit Posts: 505
    edited December 1969

    Linwelly said:
    unfortunately I'm not able to explain the fenomenon to you but at the same situation for several times when I added an Uberenvironment light. So It seems to me the cause really is the uberenvironment. In my last render I somehow bypassed the problem even though I used the Uberenvironment light. I'm not yet sure what I made different this time.
    Hope to get reason an wa way to avoid this as well, so good luck

    Thanks for the setting link. I set my render settings for the draft version, and reloaded the same scene that took 90 minutes to render last night, and it took less than 5 minutes to render, with almost no difference in the render look. At least nothing that will be an issue in my project. I knew there had to be a way to turn down some of the render conditions... I just had no idea which ones.

    As for the system changes, I know some people basically use flash drives to to run graphic heavy processes, but where in my case it's processor power and not memory, I didn't think it would help, but it never hurts to ask.

  • ShawnBoothShawnBooth Posts: 465
    edited December 1969

    I would add (IMO) - Uber should be used as a base with additional lights used to light the scene. I wouldn't use Uber all by itself as it's rarely enough.

    I typically start with Uber, drop it to 60% and then start lighting.

  • Richard HaseltineRichard Haseltine Posts: 100,848
    edited December 1969

    There are several uber lights, and shaders - it's a brand name - so you need to specify which you mean.

  • ShawnBoothShawnBooth Posts: 465
    edited December 1969

    There are several uber lights, and shaders - it's a brand name - so you need to specify which you mean.

    So sorry, you're totally right.

    I am referring to UberEnvironment2. It's a great base (or ambient light) to start lighting from.

  • Deep somewhere in the UberEnvironment2 documentation is a very key detail: When using raytracing with your uber envorinment and your lights, every surface you are rendering in your scene must have trace displacements turned on. And the default is OFF, which I think is dumb since raytracing is so common these days. What turning trace displacements on does is take each piece of geometry, figure out the light for the entire surface or group, and then render it after it has figured out averages, instead of each ray of light hitting a piece of geometry and giving you a color for that pixel, and then calculating the next pixel... and the next with slight variations... causing the pixellated look. Turning trace displacements on smooths out the look considerably, particularly in the shadow areas of light colored objects such as skin. What will happen with your rendering experience is that it will seem to stop, do nothing for a while, and then wiz quickly through an object before stuttering to a halt..

    Trace Displacements ON does little to slow down render times for simple geometry like walls, but consider turning raytrace off and just using deep shadow maps on your lights, and trace displacements off on your surfaces like skin and hair, when you are doing renders for which accurate colors in your shadows is not essental, such as when a scene is in the planning stages, or while you work on a different part of the scene. When setting up your scene, set your Uber Environment to Ambient, which wont give you any shadows, but wont cause the render choke of Occlussion or Indirtect Light. Also another hint: Hide your hair, or turn it to ambient only, as raytracing does not like transparent surfaces. For this reason hide volumetric effects until you need them as well. Get rid of any lights that you aren't using. In fact, if you don't need it, hide it. I test render with body parts floating hairless in mid air with only those objects around them which might cast a shadow or influence my perception of color.

    Per OmniFreaker:

    Trace Displacements
    When using raytracing (occlusion, shadows), this must be turned on in order for geometry to shadow properly. This will slow down renders.

    Post edited by Whitehart Creative Arts 3-D (fionathegood) on
  • cdemeritcdemerit Posts: 505
    edited December 1969

    Deep somewhere in the UberEnvironment2 documentation is a very key detail: When using raytracing with your uber envorinment and your lights, every surface you are rendering in your scene must have trace displacements turned on. And the default is OFF, which I think is dumb since raytracing is so common these days. What turning trace displacements on does is take each piece of geometry, figure out the light for the entire surface or group, and then render it after it has figured out averages, instead of each ray of light hitting a piece of geometry and giving you a color for that pixel, and then calculating the next pixel... and the next with slight variations... causing the pixellated look. Turning trace displacements on smooths out the look considerably, particularly in the shadow areas of light colored objects such as skin. What will happen with your rendering experience is that it will seem to stop, do nothing for a while, and then wiz quickly through an object before stuttering to a halt..

    Trace Displacements ON does little to slow down render times for simple geometry like walls, but consider turning raytrace off and just using deep shadow maps on your lights, and trace displacements off on your surfaces like skin and hair, when you are doing renders for which accurate colors in your shadows is not essental, such as when a scene is in the planning stages, or while you work on a different part of the scene. When setting up your scene, set your Uber Environment to Ambient, which wont give you any shadows, but wont cause the render choke of Occlussion or Indirtect Light. Also another hint: Hide your hair, or turn it to ambient only, as raytracing does not like transparent surfaces. For this reason hide volumetric effects until you need them as well. Get rid of any lights that you aren't using. In fact, if you don't need it, hide it. I test render with body parts floating hairless in mid air with only those objects around them which might cast a shadow or influence my perception of color.

    Per OmniFreaker:

    Trace Displacements
    When using raytracing (occlusion, shadows), this must be turned on in order for geometry to shadow properly. This will slow down renders.


    Thank you very much for that, It will most definitely help in improving the quality of my work.

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