Friday 14 November 2014

Octane Notes

Following is general info on Octane for my Octane plugins and Octane Standalone, which may not be provided in the Octane manuals, but which will hopefully help people with the more common issues encountered.  If you have an questions - pls post of the Otoy Forums (http://render.otoy.com/forum).

Pls see http://poserphysics.blogspot.com.au/2016/03/installing-nvidia-drivers-on-linux.html for installing Nvidia drivers in Linux.

Octane will not run, or you are getting cuda errors: 
1) Reboot and try again
2) Check the Octane Log (in the plugin or Octane Standalone)
3) If a 3d app Octane plugin will not run, check to make sure Octane Standalone renders.  If it DOES, it may be another plugin which is interferring with Octane.  In this case, disable all plugins other than the Octane plugin and see if it works.
4) Cuda error 999's are generally a driver or hardware problem.  Under-clocking your card may resolve this issue if it is a hardware fault.
5) If getting cuda errors part way through a render or animation, your card may be overheating.  Use GPU-Z to check.

6) If the Viewport is black,  check to ensure at less one Cuda device is selected in the Cuda Devices panel of the plugin/Standalone.
7) You will get a cuda error if you have exceeded the triangle limit of Octane.  The current triangle limit is 19.6 million (if you have no motion blur, hair strand data or displacement).  If your scene has quads, each quad will result in 2 Octane triangles.  Octane 3 will remove the triangle limit.

Noise-Free Renders
1) Reduce Imager->Hot Pixel (to remove fireflys)
2) Increase Kernel->Caustic Blur (to smooth out Specular and Glossy material highlight noise)
3) Use the Emitters tips below
4) Reduce Kernel->GI Clamp (Try 1.  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 (thank Marcus for this one)
5) 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).

Emitters
1) Use low-polygon emitters if possible (a single polygon plane is best)
2) For IES emitters, load the IES file into a Greyscale Image node connected to the Distribution pin of the Emission node.
3) If using an IES distribution with a Spherical projection in Normal coordinate space, you will get light emitting from each polygon in the mesh in the direction of the normals
4) If geometry is connected to an Octane Placement or Scatter node, the emission power will be adjusted by the Placement/Scatter scale.

Auto-focus
1) When Auto-focus is enabled, thefocus distance is determined from the camera to the geometry at the very middle of the render.  If there is no geometry in the middle of the render, the focus distance may be invalid, and the render will be out of focus.

Displacement Mapping
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

Round Edges
1) Round Edges require that the edge between the two surfaces has shared vertices.  
2) Round edges should only be used for very small amounts of rounding.  For large round edges, use geometry.

5 comments:

  1. Hey, I'm using the Modo plugin and while I've been able to get the displacement to work, the displacement I'm seeing in Octane does not match up with the displacement I'm seeing in Modo's Preview Render (procedural noise). Also, Modo shader bump maps don't seem to work in Octane either.

    I'm new to Octane so please forgive me if these are obvious questions. I did go through the manual and wasn't able to find answers there.

    C Jones

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    Replies
    1. Hi - can you pls ask questions in the Modo plugin forum at https://render.otoy.com/forum/viewtopic.php?f=34&t=42581 . Modo procedural textures are not supported by the plugin (pls see point 4 of https://docs.otoy.com/Modo/?page_id=185 ). Paul

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  2. hi, icant download octane render, please help me. thanks. i need this plugins

    ReplyDelete
    Replies
    1. You can download Octane Standalone and all the Octane plugins from render.otoy.com.

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