Note: Known issues in the legacy Arnold Shader Network Editor since Cinema 4D S24:
Drag & drop nodes to the node editor does not work as expected:
Drag & drop an Arnold Material to create a reference. A Cinema 4D Object Operator node is created instead of an Arnold Material reference node.
Drag & drop an object to create an object reference. A Cinema 4D Object Operator node is created instead of an Arnold object node.
Drag & drop a Vertex Map to create a Vertex Map shader. A Cinema 4D Object Operator node is created instead of an Arnold Vertex Map shader.
Ctrl + drag a shader in the node editor in S24 creates two copies instead of one. shift + drag and Shift + Alt + drag does not work.
Enhancements
Pyro render performance improvements: Faster initialization and reduced memory usage, when rendering an uncached Pyro simulation. In our test scenes we've seen 1.25x faster scene initialization and 2.85x less memory usage on average. (C4DTOA-2963)
Pyro GPU render: Uncached Pyro simulation can now be rendered on the GPU. (C4DTOA-2963)
Density and emission in default Pyro volume shader: Density and emission in the default Pyro volume shader (when no shader is assigned to the Pyro object) is now adjusted based on the Cinema 4D and Arnold project scale. For instance, if the Cinema 4D project is in centimeters and the Arnold scene is in meters, density and emission is scaled up 100x. This change does not affect old scenes. (C4DTOA-2967)
Optimized Arnold Sky viewport display: Faster viewport display of HDRIs, when the texture is defined with a relative path. (C4DTOA-2972)
Global matrix in the object shader: The object shader can now output the transformation matrix of the referenced object, that can be connected to any matrix type input, such as uv_transform.matrix. (C4DTOA-2973)
Motion blur with set_transform: The set_transform operator now has a matrix attribute, that can be animated and driven by any object from the scene. This allows set_transform to apply animations and get correct motion blur. (C4DTOA-2945)
Bug Fixes
C4DTOA-2872 - Random crash in the legacy node editor after undo
C4DTOA-2874 - Rare IPR crash when adding new tags to the scene
C4DTOA-2884 - Rare crash when redrawing image in the IPR window
C4DTOA-2962 - Crash when closing the IPR window while the scene is updating
ARNOLD-13043 - DeepEXR and Cryptomatte use more memory than needed
ARNOLD-13128 - Node init and update happens twice when doing a negative AA progressive render
usd#1359 - Refresh the Arnold instancer when the prototype mesh points have changed
usd#1483 - Indexed normals with vertex interpolation are now converted properly
usd#1462 - Ensure shader scope doesn't appear twice in the hierarchy
usd#1477 - Fix the motion blur with interframe geometry samples in the render delegate
usd#1419 - Add a note in the README about the USD_ASSIGN_PROTOTYPES_DETERMINISTICALLY environment variable, which fixes the flickering instances in cryptomatte issue
usd#1426 - Skinned transforms are now correctly used on the skinned meshes
System Requirements
Windows 10 or later, with the Visual Studio 2019 redistributable.
Linux with at least glibc 2.17 and libstdc++ 4.8.5 (gcc 4.8.5). This is equivalent to RHEL/CentOS 7.
macOS 10.13 or later.
x86_64 CPUs need to support the SSE4.1 instruction set. Apple Mac models with M series chip are natively supported.
GPU rendering works on Windows and Linux only and requires an NVIDIA GPU of the Ada, Ampere, Turing, Volta, Pascal, or Maxwell architecture. We recommend using the 525.89 or higher drivers on Linux and 528.49, or higher on Windows. See Arnold GPU for more information.
The cache also needs to be re-populated after installing a new Arnold version, updating to a new NVIDIA driver, or changing the hardware configuration of GPUs on the system. More information can be found here.