arnold6 USD tests

I am testing new Arnold6 native USD support. Fist time to pixel is super fast, 2-3 seconds on arnold6 CPU with 1 million splines USD asset 8 sec. on Arnold6 GPU in Houdini and Gaffer.

Its a shame, that’s Autodesk HtoA plugin is is unusable. interactive rendering does not takes any updates, except shader values changes and light exposure changes. Also, Arnold6 GPU have big render artifacts with spline render mode set to “Thick”. what it look likes a cool shader, are actually render artefacts.

also arnold6 GPU renders 5 times slower then CPU version as soon i turn on SSS or transmission. ( quadro RTX5000 vs Xeon 6 core at 2.4 GHz )

atmossphere volume in arnold

rendered with Arnold in Houdini. I’ve tried the atmosphere volumes the first time. easy to setup. The render time was quite slow on the volumes, typically for volumes, but much faster then render the screen envr with VDB cloud. I’ve used a mesh light for inner character illumination. 

it’s a shame I could not use Arnold 6 GPU, because its missing features. Volumes would boost get huge speed boost with volume raymarching on a GPU. I had to use a denoiser from Affinity Photo in dark areas.

with Arnold 6 GPU it does not drop any errors, you have to wait 1-2 minutes if data is loaded to GPU and starts the rendering or not. even a wrong file pass to an Hdri image makes Arnold GPU drop out, you sitting and wait in front of a black screen and don’t know if it will render or not.

light simulation

I’ve made a simple scene to test the physics of light. for proper light calculation, I used spectral render Indigo and Octane.

Indigo has multiple Engines, standard Spectral Path tracer on CPU or GPU and Bidirectional path tracing with MTL sampling (metropolis Light Transport). Octane has only default Spectral Path tracer on GPU but includes an MTL sampling method. I’v also added Renderman 23 to the test with its unified rendering integrator. It supports bidirectional path, manifold caustics and path guiding on the CPU.  

Another render engine like Arnold or Cycles with regular Path tracing would impractical fro complex light calculation tasks.

The base scene is Sphere and squashed Sphere underneath inside a volume box (uniform VDB).      

The following image is the result of Indigo Renderer with BiDirectional path tracing and MTL. It was by far the fastest rendering.

NNody simulation with openCL

an N-Body simulation which calculates a gravity field and corresponding velocity and acceleration contributions accumulated by each body in the system from every other body. Shows how to mitigate computation between all available devices including CPU and GPU devices, as well as a hybrid combination of both, using separate threads for each simulator.

the setup in Houdini : 120.000 stars simulated with the openCL wrangle in a Solver. the graphic card on my macbook RX420 GPU is about 25 faster then NBody in C/Vex on the I7 CPU

realtime nbody on my macbook with 40.000 stars