C4DtoA 4.7.8: USD improvements, faster volume intersection, faster baking, and Cryptomatte on GPU

[Stephen.Blair]

C4DtoA 4.7.8 uses Arnold 7.3.5.0 and is a minor feature release, bringing new shader presets, and Scene Export improvements.

Installation

• Download Arnold for Cinema 4D from your Autodesk Account. See Download Arnold for more information about downloading C4DtoA from your Autodesk Account.

• Follow these installation instructions.

Cinema 4D Compatibility

• 2023.0.0 and above
• 2024.0.0 and above
• 2025.0.0 and above

Enhancements

• OpenPBR shader presets: OpenPBR shader presets are now shipped with C4DtoA. You can load them from the Presets tab or from the Asset Browser. (C4DTOA-3242)

  

• Standard hair shader presets: Standard hair shader presets are now shipped with C4DtoA. You can load them from the Presets tab or from the Asset Browser. (C4DTOA-3301)

  

• Export Save settings to scene file: If regular and/or multi-pass image outputs are defined in the Cinema 4D render settings, they are now exported to the Arnold scene file during Scene Export, in case the selected image format is supported by Arnold. (C4DTOA-3277)

• Export display driver to scene file: The Arnold display driver is now exported to the scene file during Scene Export as a jpeg driver, if it is the only output in the scene (native image Save is disabled and no other Arnold drivers are in the scene). Imagers assigned to the display driver are exported as well. (C4DTOA-3277)

• Ask to overwrite scene files: Scene Export now asks to overwrite scene files if they already exist. (C4DTOA-3278)

• Optimized Cryptomatte and GPU support: Arnold now has an internal implementation of Cryptomatte that adds support for GPUs and improves performance on CPU. Cryptomatte now consumes less memory for samples, making it easier to use higher AA settings, progressive rendering, and adaptive rendering (when properly used with FIS). In a simple scene rendered at 640x480 resolution with three cryptomattes the below table shows improvements in peak memory. (ARNOLD-11042)

CPU	7.3.4.1	7.3.5.0
fixed-AA	1346MB	442MB
progressive	3433MB	532MB
adaptive	8584MB	441MB

GPU	7.3.4.1	7.3.5.0
fixed-AA	-	799MB
adaptive	-	810MB

• Corrected clamping of OpenPBR metallic lobe: The OpenPBR metallic lobe Fresnel previously exhibited energy gain when the specular_weight parameter was increased above 1. This has been corrected so that the Fresnel conserves energy in this case, saturating to a mirror reflection in the limit of high specular_weight.

• Improved instancing in the alembic procedural: Instanced geometries are now better handled in Alembic. This fixes the known issues with make_instance, which is now enabled by default. (ARNOLD-15209, ARNOLD-8364, ARNOLD-8924, ARNOLD-7818)

• Faster OpenVDB volume intersection: Intersecting OpenVDB volumes are optimized for many-cores. Scenes where volume::intersection is a sizable component of render time can see large speedups. One scene where it accounted for 73% of render time on a 128-core machine saw the volume::intersection time drop to 16% of total time, for an overall 3x speedup in render time. (ARNOLD-15448)

• Faster uv_camera baking: The uv_camera.grid_size default is now 0 instead of 16, where 0 specifies that the grid_size is automatically chosen. Using the new default, baking a sphere with 800k triangles is now 6.5x faster than the previous default. (ARNOLD-15441)

• Add more options settings to image metadata: Images with metadata, such as EXR files, now include arnold/AA_samples_max, arnold/AA_adaptive_threshold, arnold/fis_filter, and arnold/fis_filter_width metadata. (ARNOLD-15521)

• [GPU] Support element linking of array parameters in ramp shaders: Arnold GPU now supports the linking of individual ramp parameter components for the position, value, color, and interpolation parameters. (ARNOLD-7120)

• OSL version 1.13.3.0: OSL has been upgraded to version 1.13.3.0. See OSL release notes for details. (ARNOLD-15319)

• MaterialX OSL closure support: the OSL closures defined by MaterialX (v1.38) for definition of layered physical materials have been ported to Arnold. For example, all the closures needed to implement the OpenPBR are now available in OSL. See OSL Shaders for more information

• Limit node update recursion: Previously, node updates were propagated up the parent chain for all node types. We now do this for shape nodes only. This can improve node update time. (ARNOLD-15492)

• Avoid unnecessary node updates: Resetting a node parameter to the current value will no longer cause a node update. (ARNOLD-15402)

• Per-parameter update dependencies: Previously, a node update dependency caused a node to be updated whenever the dependency node was modified. We now define these dependencies based on parameters, so the node update is triggered only when one of the specified parameters on the dependency node was modified. (ARNOLD-15483)

Incompatible Changes

• Missing dependencies: Custom nodes must declare all dependencies. Now that Arnold uses per-parameter dependencies, any missing dependencies will result in invalid data that may cause crashes or hangs. Also, shaders that depend on render camera values must declare a dependency on options.camera so that the shader is updated when a new camera is set. (ARNOLD-15483)

Bug Fixes

• C4DTOA-3296 - Python warning when verifying plugin version
• C4DTOA-3297 - Material asset preview renders with watermark
• C4DTOA-3298 - Wrong color space in shader presets
• C4DTOA-3302 - Tx Manager incorrectly shows outdated Tx files

• ARNOLD-11891 - Random crashes when using the Maya hypershade
• ARNOLD-15542 - Crash when modifying light group array on a mesh with instances
• ARNOLD-15478 - [GPU] Hangs and crashes with uv_camera
• ARNOLD-13968 - Add execute permission to ADPClientService on Linux
• ARNOLD-15454 - Support overriding a user property on an instance if defined already on parent
• ARNOLD-11794 - Vector type shaders render black when assigned to a shape