Before you submit an Octane support email/forum post....

Things to check prior to contacting support via the Octane forums, or email, regarding any of my Octane plugins....


Check the on-line documentation to see if your question is answered there -> https://docs.otoy.com/#

If you have any type of video card or Cuda error or problem:


1) Reboot
2) Install the latest Nvidia driver
3) Re-install Octane Standalone (any version) from the .exe installer (this will set the Nvidia driver time-outs)
4) Make sure you have not overclocked your card (use MSI Afterburner http://www.guru3d.com/files-details/msi-afterburner-beta-download.html for this)
5) Install and run GPU-Z (https://www.techpowerup.com/downloads/SysInfo/GPU-Z/) and check your GPU temperatures.  Make sure each of your rendering cards is providing valid metrics on the Sensors tab (if not, that card is faulty).

Cuda errors 999 and 719, are usually caused by a hardware problem.  If this happens, check to see if Octane Standalone also produces those errors - if it does, then  UNDERCLOCKING your card (as per step 4 above) can sometimes fix this.

When contacting support make sure you post :-
1) the Octane Log (or error dialog) showing the full error message
2) What Nvidia drivers you are using.  Refer to point 2) above....
3) If the error is in an Octane plugin, is Octane Standalone rendering OK?
4) List the specific card(s) you are using

Artifacts in renders:

1) Check the Kernel->Ray Epsilon.  Check the plugin manual at https://docs.otoy.com/# for the recommended settings.

If the issue is regarding noise in renders:

1) Reduce Imager->Hot Pixel (to remove fireflys)
2) Increase Kernel->Caustic Blur (to smooth out Specular and Glossy material highlight noise)
3) When using emitter geometry, use low polygon surfaces (such as a single polygon plane).  Avoid having emitters behind glass (ie. behind specular surfaces) - instead add an additional geometry emitter over the glass and set the opacity to 0 (so the light emits but the geometry is not visible).
4) Reduce Kernel->GI Clamp (Try 10.  Otoy recommend a GI Clamp of ~10-100x the inverse of the exposure)
5) If you have noise in dark areas this may be due to paths being terminated early, so reduce Kernel->Path Termination Power
6) If the light illuminating the scene has come through a specular (glass) material, using “pmc” rather than “pathtracing”.  In this situation you can also reduce “kernel”->”direct_light_importance” to give the light that has passed through the glass more priority.  Also, you can let more direct light through the glass by reducing the glass material’s opacity (from 1 to say 0.2).
7) If you have had to set your Imager->Exposure substantially higher than 1 (ie. 2 or greater), then there is not enough light in your scene, in which case increase the emitter and/or HDR power.

If the issue is regarding Displacement:

1) If using a Displacement map, remove any Bump or Normal maps.
2) If you use a Displacement "Amount" of 0, the object will not render
3) Octane assumes black pixels in the displacement map have 0 displacement.  If using a displacement map where 0 is a negative displacement (for example, a map generated from ZBrush), put a "Shift" of negative half the "Amount" (ie. if the Amount is 0.01, the Shift will be -0.005)
4) Large polygons with displacement will render artifacts if the displacement Amount is small.
5) Displacement mapping requires UV Projection surfaces.  It requires a displacement texturemap, and procedural textures and Octane nodes which modify the displacement texturemap will be ignored.  Similarly, the Displacement Texture Greyscale Image "Power", "Gamma" and "Invert" pins are ignored
6) Very large displacement "Amount" values may position vertices in an invalid position which may crash Octane.  So start with small (0.001) Amount values and increase from there.
7) Displacement will only work on surfaces which have been UV mapped (and have UV coordinates)
8) The Power, Gamma, Invert and Border Mode of the Image node used as the Displacement Texture will be ignored when determining the displaced surface
9) Displacement on very long, thin polygons will render with artifacts
10) Only UV Set 1 is support for Displacement image maps (ie. If Set 2 or 3 is specified, Set 1 will still be the UV set used).

Installing Nvidia Drivers on Linux

If you are going to use Octane on Linux, you will need to install the Nvidia drivers.  As of Octane 3 alpha 5, you will need at less Nvidia driver version 353 installed in order to render.  There are a number of approaches to installing the Nvidia drivers on Linux, and having gone through the pain of installing and updating Nvidia drivers on a number of Linux installs this week, I though I would post my workflow.  This workflow is based on using the Nvidia driver installer from Nvidia, and will vary depending on the type and ago of your Linux distro.

1) Determine which is the correct, most recent driver for your card via http://www.nvidia.com/Download/index.aspx?lang=en-us and download the installer.  Make the installer executable (ie. "sudo chmod +x ~/Downloads/NV*.run")

2) [OPTIONAL] Remove all existing Nvidia drivers (Ubuntu = sudo apt-get remove nvidia*).  I'm not sure this step is absolutely required.

3) Install the kernel headers and source (this will vary depending on your Linux flavour).  For Red Hat, Centos, etc see http://www.dedoimedo.com/computers/centos-7-nvidia.html. For Ubuntu it will be "sudo apt-get install dkms build-essential linux-headers-generic".  If you have changed your build environment (ie. changed gcc/g++ to be an earlier or later version than came with your distro, then you might need to change this - easiest option is to remove then reinstall gcc/g++).

4) Blacklist or remove/uninstall the Nouveau driver.  Blacklist on Centos as per the above link.  To blacklist on Ubuntu, see http://www.allaboutlinux.eu/remove-nouveau-and-install-nvidia-driver-in-ubuntu-15-04/.

5) Reboot

6) Stop your X server.  Mint is Ctrl-Alt-F2, or in Centos open a terminal and "init 3".  If the Nvidia installer gives an error indicating the X server is still running, kill the process via "sudo /etc/init.d/lightdm stop" (Cinnamon) or "sudo /etc/init.d/mdm stop" (MATE), etc.

7) Run the Nvidia driver installer as root

8) Reboot 

If you cannot get the driver working, and you are using Cinnamon, as a last resort, install  MATE, since it does not use the graphics acceleration that Cinnamon does, so is more tolerant to incorrectly installed graphics drivers.