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HtoA 5.5.0.028 Oct 2020 

 

HtoA 5.5.0.0 introduces  and is a feature release bringing a brand new post-processing framework (imagers), support for nested Arnold 6.1.0.0dielectrics, much improved progressive and adaptive sampling, on-demand texture loading on GPU, integration improvements for Solaris, and Arnold-

 (4e5710fa).USD

Installation

Download Arnold for HoudiniFollow these installation instructions

 

System Requirements

Houdini, Houdini FX, Houdini Indie and Houdini Education

17.5.46018.0.59718.5.351

Windows 7 or later, with the Visual Studio 2019 redistributable.Linux with at least glibc 2.12 and libstdc++ 3.4.13 (gcc 4.4.7). This is equivalent to RHEL/CentOS 6.OSX 10.11 to 10.15. Note that macOS 11 Big Sur is not certified.CPUs need to support the SSE4.1 instruction set.GPU rendering works on Windows and Linux only and requires an NVIDIA GPU of the Turing, Volta, Pascal, or Maxwell architecture. We recommend using the or higher drivers on Linux and , or higher on Windows. See 455.38 457.09 (Quadro), 457.30 (GeForce) Getting Started

 for more information.with Arnold GPUOptix™ denoiser requires an NVidia GPU with  and above. CUDA™ Compute Capability 5.0

 

Enhancements

Imagers

We're introducing a brand new framework to apply post-processing effects such as color correction, vignetting, or tone mapping. A new type of post-processing nodes called operate on pixels before the output driver. Imagers can be chained. The initial set of imagers consists of:imagers

New Windows system requirement

If you use the option to install HtoA, you must manually install the Microsoft Visual C++ 2015-2019 Extract contents onlyRedistributable.

The VCRedist install is in the HtoA folder. For example:redist

\\SERVER\htoa\htoa-5.5.0.0_r5b05c8c_houdini-18.5.351\htoa-5.5.0.0_r5b05c8c_houdini-18.5.351\redist\VC_redist.x64.exe

 

 

Autodesk Network Licensing in Arnold 6 requires new license files with an updated 2020 version. Please follow the instructions on this page to generate your license file. More info about Arnold 6 licensing can be found here.

imager_exposureimager_color_correctimager_lens_effectsimager_white_balanceimager_tonemap

Imagers work both in batch and interactive contexts. While imager parameters can change interactively during rendering, adding a new imager currently requires the render to be restarted, so it's a good idea to add the ones you will need to adjust at the beginning of an interactive session. We are looking at removing this limitation in a subsequent release. (core#8368, core#9716, core#9723, core#9724, core#9867, core#9868, core#9869, core#9938).

Color Correct

Lens Effects (vignetting)

 

: Nested dielectrics Physically-correct reflection and refraction of rays in scenes with adjacent dielectrics, such as liquids in glass vessels, has been implemented by resolving overlapping, i.e. "nested", dielectrics via a priority system. This allows for more realistic renders of scenes such as glass containers with liquid contents and bubbles, correctly accounting for the change in the index of refraction as rays refract through the transparent media. The new dielectric_priority parameter on the shader assigns a priority to the internal standard_surfacedielectric medium of the closed transparent object the shader is assigned to. These priorities specify that in an area of overlap of two transparent objects, only the priority dielectric medium exists (see the schematic glass of water below). The priority is simply a highestsigned integer (default 0), which can be increased or decreased as needed to define the dielectric medium in the overlap areas. If priorities

The effect can be disabled globally with are made equal, then media are effectively blended in the overlap. options.dielectric_priorities ( in case you need to revert to the legacy mode, in the tab of the render settings) Nested Dielectrics Advanced

(core#6023)which does correctly compute the refractions. not

Standard setup of a glass of water with an ice cube, using the priority system. Rollover image to view the result with the global dielectric_priority: disabled (not physically correct).

 

Nested dielectrics examples

Improved progressive and adaptive sampling: Better sampling now results in much faster noise convergence, especially with adaptive sampling enabled. (core#9941)

Left: Arnold 6.0.4.1 - Right: Arnold 6.1.0.0 - Both images rendered using the same settings: a = 0.015 (default)daptive_threshold

Improved performance on Windows: Arnold now runs on average 7-8% faster overall on Windows. (core#5481, core#9876, core#9975)Improved IPR interactivity: IPR interactivity on both CPU and GPU, especially when moving the camera in a scene with many nodes (thousands to millions of meshes, ginstances, lights, shaders, etc.), is improved. For instance, a scene with 24,433 ginstances and simple

(core#8662, core#9918, core#10027, core#10029)shading went from 8 fps to 14 fps on the CPU and about 3 fps to 20 fps on the GPU. Improved performance in Toon on Windows: The used for toon rendering should now be faster and scale better especially contour_filteron Windows, with up to 3x speedups on AMD Threadripper 2 and up to 4x speedups on AMD Threadripper 3 CPUs. (core#7844)Toon AOV prefix : The shader has a new optional  that will be prepended to the toon AOVs' names. For instance, if  toon  aov_prefix

is  , the toon diffuse AOV will be written out to  . This can be used when you need to access both  aov_prefix "toon_" "toon_diffuse"the toon AOVs and the core's LPE AOVs. (core#9823)Improved soft creases in adaptive subdivision: Normals for soft creases follow the geometry closer for low iterations. (core#9971)

All cube edges have sharpness 3 creases. The diagram shows the new (top) and old (bottom) normals for 1, 2, 3, and 4 iterations.

AA seed now included in EXR metadata: The AA seed of a render is now also included in EXR metadata. (core#9895)Improved support for MaterialX: Material nodes are now supported, shader nodes and node graph outputs can be connected to material node inputs. Node definitions implemented as node graphs can contain both Arnold native shaders and MaterialX standard library shaders.

This is useful to build reusable and portable material groups and definitions, for example by using standard_surface with MaterialX patterns. The environment variable can now point to directories and load multiple node definitionsARNOLD_MATERIALX_NODE_DEFINITIONS (see

) ( core#9618, core#9926)here core#9204,

Fix the ETA and elapsed time counters for IPR renders (htoa#1544)Add an AOVs section for the shader (htoa#1568)toonCreate Advanced tab in Arnold ROP sample settings (htoa#1569)Add the Lock Sampling Pattern, replacing the Noise Seed on the Arnold ROP (htoa#1571)

Solaris

 Add AOV light groups and menu to Solaris lights (htoa#1502) Support Solaris shader translation for H18.5 (htoa#1537, htoa#1573) Add portal mode for dome light LOP (#1536) Add option to the Solaris render settings LOP (htoa#1528)enable_adapative_sampling Add properties to Solaris render settings (htoa#1553)AA_sample_clamp Update the default values of transmission weight and camera weight on the solaris Light LOPs (htoa#1557) Support the Arnold OSL inline shader VOP in Solaris (htoa#1560) Fix camera pivot when orbitting the camera in Houdini 18.5 (htoa#1566) Per face material assignments for the render delegate (usd#520)

GPU Enhancements 

Improved on-demand loading of textures: The GPU renderer can now partially load textures which results in important GPU memory savings when using tiled and mipmapped textures, such as from .tx textures. In a typical scene, the amount of memory needed for textures could be reduced to be up to 5x smaller. A recent driver is needed for this feature (core#9984).

Initial support for light linking: Initial support has been added for light linking. Currently, there is a limitation that light linking is not supported on volumes. (core#9890)Support light AOV groups: Adding light AOV groups in LPEs is now supported on the GPU. (core#9882)Improved OSL JIT compilation performance: OSL JIT compilation performance has been improved, meaning faster time to first pixel and improved interactivity when using OSL shaders. The improvement averaged 6.3x faster during testing. (core#10004)Improved support for min pixel width and thin-walled sampling: We have improved compatibility with the CPU renderer for min pixel width on the GPU and thin-walled sampling on zero roughness surfaces. (core#9291)Partial GPU IPR output: Like on the CPU, when the FPS goes below a certain threshold (5fps by default), instead of not displaying anything, the GPU will at least display the pixels that have finished rendering. Since GPU currently renders pixels in a top to bottom ordering, this will result in the top part of the image being updated while the lower part becomes stale. (core#10027)

OptiX cache location change: The Optix cache directory used to be of the form: arnold-<ARNOLD_VERSION>_driver-. Now it is simply  . This means the same cache will be used across driver and Arnold versions. Upgrading to a <DRIVER_VERSION> arnold

new version will still likely cause a lengthy JIT/cache pre-population, but it will reduce disk usage as old versions will not stay around-consuming disk space. (core#9239).

USD Enhancements 

Light Shaping: The procedural now supports the UsdLuxShapingAPI, allowing the use of spot and IES lights ( ).usd#344UsdTransform2d: The render delegate now supports the UsdTransform2d preview shader ( ).usd#516Per-face material assignments: The render delegate now supports per-face material assignments ( ).usd#29Render Stats: The Render Delegate now returns render stats via GetRenderStats. For now, this is used to show render progress in Solaris (

).usd#537

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Schema for custom procedurals: The schemas now include ArnoldCustomProcedural for describing custom procedurals ( ).usd#487Schema updates: Schemas now support cameras, render settings, and new output types ( ).usd#500Parent Scope: There is a new flag to specify a custom root for all exported prims ( ).usd#292ST for Texture Coordinates: Texture coordinates are now written as primvars:st to match the USD convention ( ).usd#542

Incompatible Changes 

Correct refractions with nested dielectrics: correct thanks to Refraction through adjacent transparent media now looks more physically resulting in a look change. If you need to revert to the legacy unphysical behavior for compatibility reasons, you can nested dielectrics

disable nested dielectrics globally by setting to False.options.dielectric_prioritiesmix_shader add for transparency: Previously, the   mode of the   also added the transparency closures, which means that add mix_shadereffects such as min pixel width would be double-counted, leading to objects disappearing. Now, we will add only non-transparency closures, while we pass through the max of the transparency closures. The old behavior can still be obtained by setting   to true add_transparency(core#9952).Skipped node updates: In order to improve IPR interactivity, we skip the per-frame node update if we believe that node has not changed. If our internal heuristics for detecting node changes is wrong and was supposed to be called, you can set the node_update force_update metadata on your node:

node_parameters{ AiMetaDataSetBool(nentry, nullptr, "force_update", true); // depends on camera node // ...}

so that Arnold will always run node_update on every render pass. At the moment, this should only be needed for nodes that access  in their  . If you do not have access to your shader's source code, you can globally disable this optimization options.camera node_update

by setting the   to false (core#8662).options.enable_fast_ipr

Bug Fixes

htoa#1572 Fix a crash seen when setting inline VOPoslhtoa#1444 Catch exception when translating materials containing undefined nodesosl

core#5518 Handle interruptions properly during procedural expansioncore#9949 mesh_light with constant black texture causes degenerate light tree casecore#9971 Subdivs: soft creases normals different in adaptive and regularcore#9978 Viewport API doesn't apply the correct matrix for nested proceduralscore#10031 Only shader node connections should use node output typecore#9361 [GPU] OptiX assert when updating texturescore#10024 [GPU] Incorrect texture selection or error when invalidating the texture cache with GPU sparse texturescore#10026 [GPU] Rare crash in OptiX denoisercore#10040 [GPU] Always report minor version field of Nvidia driver as two digitscore#10048 [GPU] Wrong progress reporting using adaptiveusd#513 Viewport representation in points mode doesn't have the correct matrixusd#543 Visibility is not checked on the current frameusd#556 motion_start and motion_end is only set if the matrix of the prim is animated

#565usd Animated transforms not translated properly if set on parent XFormsusd#569 Render delegate not picking up OSL shader parameters

#570usd USD procedural is not picking up OSL shader parametersusd#574 Incorrect display of curve widths in Solaris when changing curve basisusd#577 Point light should have zero radiususd#580 The Render Delegate's depth range is incorrect if USD is at least version 20.02