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 )
i am starting to use Image EngineGaffer (opensource software) for some private projects. but vanilla version of the software is quite naked and not very user friendly, so i decided to pimp the software with my own extensions.
first step, pimp the node icon’s and make it 4k screen ready.
the colours are not quite right, I am trying to integrate kelvin colour temperature. the current colour is based on density and speed.
In this simulation, I assumed 48% amount of negative gravity to fill the mystery of dark matter. I used 1 million nbodies for the simulation. for the steps, I am planning to add finer particle streams to get more details.
I’ve tested RenderMan with spline rendering. it’s much faster compared with baked Geometry. the spline primitives are very good in Renderman.
I’ve stopped the test with mantra after 10 minutes, it is super slow even with optimized render settings.
the Renderman images rendered for 3:20 on a 6 core Xeon 2.7ghz with pxr pathtracer. 4k resolution
rendering splines directly saves a lot disk space and meshing time. interactive rendering was super responsive.
Octane 2019.2 renderings is very fast, I’ve used the geo to render it. 2 minutes, as except its lot faster the CPU renderings. the spline rendering in octane does features custom width yet.
Octane gives physical correct shading out of the box. Renderman the shading is extreme flexible with NPR renderings, which is hard to get in Octane. the IPR responsibility was a little slow with shader tweaks.
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.
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.
‘ve open a Houdini and rendered with RenderMan 22.6. I used only xrDirectLighting integrator and the render speed was super fast on CPU. I’ve ditched the Pathertracer for this scene, it gave no visual benefits/improvement in this case. Pure spline rendering, no Polygon meshes.