Best Iray Settings for Daz Studio

Many within the Daz community often embark on a quest across forums and YouTube to unearth the holy grail of Iray render settings. Even seasoned users occasionally find themselves refreshing their knowledge of terminologies. Understanding the best settings and their functions can be daunting, especially for newcomers navigating these complex options.

Rendering times in Daz Studio can stretch for hours depending on the project. While optimal settings may lead to extended waits, default configurations might neglect potential enhancements achievable with our hardware.

This guide aims to be your ultimate stop for mastering everything about Iray render settings. Bookmark this comprehensive article for frequent references as you journey toward becoming a rendering pro in Daz Studio!

This post delves deeper than ever into the NVIDIA Iray Engine. Let’s get started.

When You Should Use the Iray Render Engine

Daz Studio presents two render engines: 3Delight, the original Daz Studio rendering engine, and NVIDIA Iray, which has expanded creative possibilities within Daz. Both aim for realism and top-tier picture quality. In this discussion, our focus is solely on NVIDIA Iray and why it’s gained immense popularity within Daz Studio.

The catch with Iray is its major prerequisite – an NVIDIA GPU for optimal performance. Unfortunately, if you’re using another top-tier graphics card like AMD, it won’t function as expected.

But, for those wielding an NVIDIA Iray card and harboring a fondness for Daz Studio, the Iray Engine is a game-changer. In fact, with the right card, using Iray becomes a no-brainer!

The Daz community has embraced Iray wholeheartedly, ensuring robust support and enjoying a new rendering technology with compatible assets. It offers quicker rendering, leverages HDRI technology, and grants full control over expansive details.

Iray Render Settings

Now, let’s unravel the plethora of settings that Iray provides. For beginners, maximizing Iray’s potential without enduring extensive render times can be overwhelming.

Iray operates precisely on your instructions! Often termed an unbiased render engine, it necessitates defining when the engine should cease rendering. This is solely achieved through settings. Once the engine begins, it’ll continue rendering until specific parameters are met. Skilled users find this level of control rewarding, but beginners might find it frustrating, potentially resulting in unnecessarily extended render times due to misunderstandings of settings.

Opening Daz Studio reveals the Render Settings tab, which can be broken down into various subsections:

General Settings

These encompass Dimension Preset, Pixel Size, Aspect Ratio, Render Type, Render Target, Image Name, Image Path, and Auto Headlamp. Each holds significant value, affecting resolution, file location, and lighting, among other factors.

For example, let’s take a look at the Auto Headlamp. Unlike many of the other settings that are largely about the file, this is often an important setting overlooked by new users, and it can directly affect how your render turns out. Think of the headlamp as, just that, a light the user is wearing, so it always casts light wherever they are looking. This is usually on by default so that you can see the scene view even if there are no lights manually added to the scene. While this is helpful while working in Daz Studio, you’ll most likely want to turn it off when you render.

Render Mode

Choose between Photoreal and Interactive for render mode. Each mode has its unique settings impacting rendering speed and quality. If you want the best results, stick with Photoreal. However, for fast iterations, Interactive is a good choice. Interactive uses different algorithms to calculate your final render result and is designed to be much quicker at the expense of the quality you’ll get from Photoreal.

Note that the settings available to you will change, depending on which mode you are using. The settings discussed here are based on the Photoreal Render Mode, however, we will point out when changes occur and a setting is only available in Interactive Mode.

Progressive Rendering

This section encompasses Update and Completion Settings, controlling the number of samples and time allocated for rendering loops.

Distinguishing between update and completion aspects can be a helpful approach when considering these configurations:

Update Configuration

This pertains to Min Update Samples and Update Interval (secs). The quantity of samples generated per render call is controlled by the sample number. Simultaneously, the interval conveys crucial information to the render engine regarding the duration it should allocate to computing each render call. Longer intervals generally enhance effectiveness, whereas shorter intervals result in more frequent updates.

Completion Configuration

In this category, we encounter Min and Max Samples, along with Max Time (secs). The minimum sample number establishes a baseline for the render loop to conclude progressively. Conversely, Max Samples instructs the render engine on the upper limit of samples to generate in each render loop. Increasing the time allocated per loop will extend render times but provides the render engine with more processing time before termination and progression to the next loop.

Converged Quality and Ratio in Progressive Rendering

By default, these settings are configured at 1 and 95%, respectively. Elevating the quality setting demands better-converged pixels, resulting in extended rendering times. Render times exhibit a roughly linear relationship with the specified value, so doubling the quality roughly doubles the rendering time.

It’s important to note that assigning a value higher than the default 0.95 may lead to exceedingly prolonged render times. The rendering converged ratio is an approximation updated intermittently, not with every render loop.

Optimization

Optimize your render with settings like Caustic Sampler and Guided Sampling, which influence lighting effects and quality.

There’s a lot to delve into regarding caustics. Essentially, caustics involve the reflection or refraction of light rays by a curved surface. Daz Studio naturally produces caustic-like effects, but if you aim to enhance these effects—especially when dealing with glass or liquids—you can activate this setting.

Enabling this setting can occasionally enhance both render quality and reduce render times. When the caustic sampler isn’t in use, enabling Guided Sampling can notably enhance render quality, particularly when combined with the Firefly Filter. However, using Guided Sampling might heavily impact your system’s memory resources. NVIDIA suggests employing this setting in the following scenarios:

Strongly occluded light sources, encompassing bright environment map content (e.g., the sun) blocked by walls, and any other strongly shadowed lights.
Volumetric rendering.
Soft shadows from large area lights, contingent on tessellating the area light.
Moderate caustics. It’s important to note that extremely sharp caustics still require sampling with the caustic sampler.

Filtering

Settings like Firefly Filter and Noise Degraining Filter eliminate undesired artifacts and noise.During rendering, you might come across random white or excessively bright pixels scattered across your image, commonly known as “Fireflies.” These usually pop up in areas with challenging lighting situations. This included filter does a good job of getting rid of these unwanted spots. For more insights into enhancing your lighting, take a look at this post.

The Noise Degraining Filter operates in two modes in Iray, depending on the render mode being used. In Photoreal mode, the Noise Degrain Filtering can be adjusted from 1 to 5, offering five distinct settings:

Pixel clipping
Smart median
Smart average
Limited blur
Limited auto blur

A setting of zero deactivates the filter entirely. Modes 1 to 3 are more conservative, focusing on eliminating noise in complex scene areas without compromising image sharpness. Modes 4 and 5 are more aggressive and should be used cautiously. Experimentation might be necessary based on the scene’s requirements.

These controls aren’t accessible in Interactive Render Mode. Instead, a simple filter is available, defaulting to a Gaussian filter that subtly blurs the image to reduce noise artifacts.

Post Denoiser Availability

Activating this doesn’t directly affect the image. It prepares additional data needed for denoising during progressive rendering. Enabling this option may slightly impact memory and performance, hence switch it OFF if denoising isn’t required.

Post Denoiser Activation

When enabled, the denoiser processes the rendered image. If not activated, it remains inactive. Changing this setting doesn’t require restarting the rendering; the next frame incorporates the chosen value. However, enabling the denoiser could significantly affect memory and performance.

Post Denoiser Initial Iterations

This option, set at 8 by default, prevents denoising of the initial iterations if the denoiser is enabled. Initial iterations might lack convergence, yielding unsatisfactory denoising results, so it’s advisable to delay the filter’s application.

Post Denoiser Denoise Alpha

When enabled, RGBA images’ alpha channels are denoised; otherwise, they remain unchanged. Note that enabling this function roughly doubles the denoising duration.

Spectral Rendering

Enable spectral rendering for a broader range of light simulation and its settings for color conversion and intent. Iray Photoreal introduces spectral rendering, a method that doesn’t just simulate light transport using tristimulus color values (RGB) but considers a continuous spectrum of wavelengths. It mimics light within the range of human-visible colors, resulting in a computed color output.

To activate Spectral Rendering, simply Enable it.

Spectral Conversion Color Space

To convert color data into spectra, the rendering core requires information about the color space in which the data is defined. Supported color spaces include CIE XYZ (“xyz”), Rec.709/linear sRGB (“rec709”), Rec.2020 (“rec2020”), ACES2065-1 (“aces”), and ACEScg (“acescg”).

Spectral Conversion Intent

When utilizing color data in spectral rendering, it must be converted into spectral data. In Iray Photoreal, the conversion aims to generate smooth spectra with some adaptability for managing reflection colors. Available options include:

Faithful – Prioritizes compatibility with color rendering but sacrifices some smoothness. Note that this setting only impacts “rec709” Color Space. For other spaces, it behaves similarly to “natural”.
Natural – Emphasizes smoothness over reflectivity. As input colors approach the gamut’s edge, resulting spectra might have reduced intensity. Consequently, highly reflective saturated colors could render darker with spectral rendering activated.

Spectral Observer

This function maps spectral values to three-channel color output. By default, the photometric rendering mode utilizes the CIE 1931 2-degree standard observer, generating CIE XYZ color output. Switching this to “cie1964” allows changing the color matching functions to the CIE 1964 10-degree standard observer.

A heads-up to users: Color theory and spectral rendering are intricate. For most users, avoiding engagement with spectral rendering might be preferable, as predicting the effects of these color conversions without prior experience can be challenging.

Utilize section objects to slice open and manipulate objects in your scene.

Tone Mapping

Control exposure, shutter speed, f-stop, film ISO, vignetting, and other settings to fine-tune your scene’s look.

Each render mode incorporates a built-in tone mapper. Default settings generally yield satisfactory results for most users, especially considering that many of us lack formal photography training. However, for those interested in leveraging these settings effectively, here’s an overview:

Exposure Value

Similar to traditional film, exposure in Iray determines the amount of light affecting the image. Excessive exposure washes out the image, while a bit more exposure can enhance low-light scenes. Conversely, reducing exposure compensates for overly bright scenes.

Shutter Speed

Expressed in fractional seconds, the camera’s shutter time dictates the light entering the camera. Slower shutter speeds permit more light, making them preferable in darker settings.

F/Stop

This denotes the fractional aperture number, following a standard series like f/1.4, f/2, f/2.8, etc. Each f-stop in the sequence allows half the light of the previous one. Note that the shader doesn’t count “stops” but requires the specific f-number for that stop.

Film ISO

In film, this value signifies the “film speed.” A zero value indicates that color scaling strictly follows the cm2_factor value.

cm^2 Factor

cm2_factor denotes the conversion factor between pixel values and luminous intensity (candela) per square meter.

Vignetting

In real cameras, light angles impacting the film affect exposure, causing darker edges in the image (vignetting). The vignetting parameter replicates this effect. Disabled at 0.0, higher values intensify darkening around the edges. A reasonable default is 3.0, akin to what a compact camera produces.

Environment

Choose between various modes impacting light sources used in rendering, with settings affecting environment mapping, ground planes, and fog effects.

The Environment tab stands as a pivotal phase in rendering, likely the area where users frequently operate.

There are various Environment Modes to select, each catering to specific scene requirements:

Dome and Scene
Dome Only
Sun-Sky Only
Scene Only

These modes significantly influence the light sources utilized by Iray in rendering computations.

The Dome’s activation or deactivation is controlled by the Draw Dome setting, serving as the canvas for your Environment Map and enabling the utilization of HDRIs in scenes. Depending on the chosen mode, the dome can have finite size, providing varied environment lookup with camera movements. Additionally, an enabled ground plane can act as a shadow catcher, offering illumination effects like reflections for scene objects. Several settings govern the ground plane’s implicit placement.

Environment Tint

This feature introduces a color tint to the dome lighting.

Environment Lighting Resolution

This option manages the pixel count for the polar angle’s resolution. The azimuthal resolution is always double the polar resolution. Higher resolutions yield more detailed visible environments and crisper shadows if fine details in the environment are small. However, increased resolutions also elevate baking times.

Matte Fog and Ground Fog

Starting from Daz Studio 4.20+, users can access volumetric control, enabling the creation of ground plane-based fog. When activated, additional settings surface to customize the fog effect, encompassing Tint, Visibility distance, and Brightness. For a closer understanding of volumetrics in Daz Studio, refer to this tutorial.

For a comprehensive understanding, balancing quality and efficiency in these settings is key. While default settings provide a starting point, fine-tuning is essential for optimal results.

Optimization and Filtering

Starting with General and Environment settings, align them with your scene’s requirements. Photoreal Render Mode is recommended for superior outcomes. Focusing on settings like Progressive Rendering ensures predetermined rendering times, while Optimization can provide specific quality enhancements.

Regarding Optimization, it’s advisable to keep these settings disabled unless specifically required. For instance, when employing the Firefly Filter, enabling Guided Sampling can notably enhance outcomes.

Particularly, activating the Firefly Filter setting is recommended across all renders.

In scenarios featuring intricate lighting and shadows, utilizing the Post Denoiser, as mentioned earlier, is beneficial. However, for simpler lighting setups or to conserve resources on less powerful hardware, it’s preferable to keep it deactivated, sparing your hardware from the demanding memory load it imposes.

If you choose to use the Post Denoiser, ensure it’s available and enabled. Additionally, adjust the Post Denoiser Start Iteration to a significantly higher value to delay its impact. For instance, if Iray computes 500 iterations, consider postponing the denoiser until 250-350 initial iterations are completed. This strategy conserves both time and memory while maintaining satisfactory results.