I started to refactor my work into Karma, but I've been stopped by the camera. My output is rendered exclusively with a VR camera, and it seems that Karma has its own camera system. Is there any way to implement the VR camera in Karma?



Additionally, I have run into a couple more problems. My files are sometimes renamed to non-commercial files, but I believe updating to a daily build solves this. For some reason my displacement textures are not rendering in Karma, I believe this is a camera dicing issue. It may be the same issue as this post. (https://www.sidefx.com/forum/topic/70878/)


Without the VR camera, I cannot continue to refactor, and will simply continue using Mantra. I'm open to any suggestions/workarounds that could solve this issue.


—


I have done some troubleshooting, here is a list of my attempts at stereo equirectangular rendering.

• I added a “/stage/ropnet” node, but this seems to only render what is in the “/obj/” directory. I'd be happy with a result where I must render in Mantra, but still have access to the USD at LOP level.
  
  
• I attempted to use the “sceneimportcameras” stage node. In this node I have selected the ‘Objects’ to be “/obj/VRcam”. I then connect this camera to a “/stage/karma” node. However, it just produces a blury picture.
  
  
• I also added a “usdrender_rop” however this seems to only render in Karma.
  
  

—


Attached is the standard LOPs demo with these different cameras. Note, you'll need to add the LOPs demo's library into the folder, or add it into the file.

Lens shaders are not yet implemented in Karma. So there is no way to render with the VR camera, or uv camera for baking or any other lens shader.

I'm not sure if this will take a USD change or if a karma specific api is possible.

KitCat
I added a “/stage/ropnet” node, but this seems to only render what is in the “/obj/” directory. I'd be happy with a result where I must render in Mantra, but still have access to the USD at LOP level.

It's not possible to render lops with mantra. (well technically you could unpack it to polygons, but this defeats the purpose.)

KitCat
I attempted to use the “sceneimportcameras” stage node. In this node I have selected the ‘Objects’ to be “/obj/VRcam”. I then connect this camera to a “/stage/karma” node. However, it just produces a blury picture.

The blurry image is because DOF is currently controlled with the fstop value of the imported camera. A value of 0 disables DOF. A global toggle was added in a recent daily build. This still doesn't help with getting in a vr camera as lens shaders are not supported.

KitCat
I also added a “usdrender_rop” however this seems to only render in Karma.

The usdrender rop can render with available hydra render delegates such as prman, redshift, Radeon Pro Render, 3Delight NSI, and others such as Arnold or Vray when they become available. I don't know of any that support lens shaders or setting alternate projection modes yet. The Renderman release notes say built-in projections are supported but I haven't seen how to enable them.

It has been close to a year and I decided to revisit this thread. Houdini 18.5 came out today, and I setup Karma with the new lens shaders [youtu.be]. The default VR lens in the shop context worked when adding lens shaders to the stage camera's Karma (Beta) tab Lens Shader VOP setting.

Thank you everyone working at SideFX for making this possible!

Attached is a simple scene with a VR camera. NOTE: This scene must be launched with 18.5 or higher.

KitCat
Thank you everyone working at SideFX for making this possible!

Hot Dog! I'm surprised legacy lens shaders work without modifications

Now that's what I call progress - I gotta admit, Karma is looking really, really nice lately. Having a “native” GPU engine in Houdini is gonna be bonkers.

This is great, except that it does not appear to work with XPU engine, only CPU rendering with Karma. Is there a solution for those who need to use XPU?

DanielCardin
Is there a solution for those who need to use XPU?

No