How to Render With AMD Radeon™ ProRender in Live Home 3D

Render Devices and CPU Threads

The first category that you encounter in the opened window is Render Devices, which lists the available devices for rendering, i.e. CPU or GPU. It is worth noting that it is normal to find only one available device for rendering in this list, as it will be the case for most users.

The CPU Threads parameter deals with the number of processing threads on the central processor (CPU) that will be involved in the rendering. It defines the number of the processor cores that are going to be used for handling the tasks of the rendering engine, when GPU is untapped or when CPU is used along with GPU for the sake of speeding up the process.

The maximum number of threads is defined by the model and characteristics of your CPU, the total number of the processor cores and threads, the level of complexity and size of the project that you are rendering. Increasing the number of threads can speed up the process of rendering with the CPU, but it can also affect the performance and stability of the system and the use of resources.

If you own a processor with numerous cores and threads, you can experiment with this parameter to find the best value for your system and your project. Keep in mind that, in most cases, you will only achieve the maximum speedup of the rendering process by using the graphics accelerator (GPU), since it is designed specifically for handling complex graphics calculations.

Camera

The Camera drop-down list contains all cameras available in the current project. Here you can choose the camera with the view that you want to render.

Resolution

Resolution controls allow you to either choose one of the predefined dimensions of the image or to set the image width and height manually. The resolution defines the number of pixels in the image distributed horizontally and vertically. It functions as two numbers, for instance, 1920 × 1080, where 1920 is the width (the horizontal resolution) and 1080 is the height (the vertical resolution). The higher the resolution, the more detailed the rendered image will be. However, rendering an image with higher resolution also requires more time and resources.

This parameter is important while setting up the rendering engine, because it impacts the quality of the rendered image and its usage. You should choose the resolution that best suits your needs, taking into account the limitation of resources. A higher resolution can be useful for printing and for large screens, while a lower resolution is suitable for publishing online and viewing on smaller screens.

Render Samples and Tiles

The Render Samples setting is the major factor defining the quality of the rendered image. To render an image, AMD Radeon™ ProRender creates a certain number of ray samples for each pixel. As new sample values for a pixel are added, the sampling results are averaged in order to calculate the color of the pixel.

The image is rendered gradually: as new samples are received, the quality of the image gets better, and the amount of noise decreases. The larger number of samples for a pixel is what provides the best results, but it requires more time for calculation of the colors. By default, AMD Radeon™ ProRender processes all pixels in the image for calculating the samples. When displaying the image, it looks grainy and noisy at first, but it gradually improves, as the rendering engine performs the computations and calculates the additional samples. This approach requires more memory and CPU resources, but it allows you to pre-watch the whole image as soon as possible and stop the rendering process in case you need to make adjustments. We also don’t recommend exceeding the value of 1000 for Render Samples.

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Instead of rendering the whole image, you can choose to Use Tiles. The tile rendering allows you to create images with higher resolution without using a lot of memory and CPU resources. To activate the tile rendering, tick the Use Tiles option in the window. As the name suggests, with the help of the Tile Size parameter, you can set up the sizes of tiles. Note that you don’t have to resort to tile rendering if you need an image with medium or smaller dimensions.

Another way of decreasing the amount of noise in the image is using Denoiser. If you don’t have time or the technical capabilities to render images with a large number of samples, you can use one of the available denoisers (see the Filters section in the window) to smooth out the noise in the image. Note that using Denoiser with high settings (Samples ≥ 800, Use Tiles) is not recommended, as it can produce an unintended blur effect.

Environment Light Intensity

The Environment Light Intensity parameter allows you to set the brightness of sunlight and moonlight. Increasing this parameter (to 5, for instance) can help you render the indoor scenes, where daylight is intended to be the main light source. Otherwise, you need to set the brightness of the lamps and other light sources in your project. If the outdoor scene is too bright, restore the default value of this parameter, which is 1.

Max Ray Diffuse

Max Ray Diffuse controls the maximum number of reflections (scatterings) of rays when using the ray-tracing rendering method. In this method, the rays of light come out of light sources and “travel” through the scene, reflecting and refracting on different surfaces in order to create a realistic image. Each reflection creates new rays that keep traveling through the scene. The process continues up until the rays reach the maximum number of reflections or until the recursion depth limit, defined by the Max Ray Diffuse parameter, is reached.

Setting the higher value of this parameter will create a greater number of reflections of the rays, allowing you to achieve reflections and lighting that look more realistic. The value that needs to be set for Max Ray Diffuse depends on the rendered scene: if the scene contains lots of plants, for example, we recommend setting the value of this parameter starting from 28 and up. If roughness on surfaces is present in the scene, you can set the value starting from 32.

If you set the higher value of Max Ray Diffuse along with high values of other settings and achieve a grainy, noisy image as a result, we recommend adding more lighting to the scene. Also, the higher value of Max Ray Diffuse can also greatly increase the time of the rendering process, especially when dealing with more complex scenes. Thus, when choosing the right value for the Max Ray Diffuse parameter, it's better to seek compromise between the quality of rendering and the time spent to render a scene.

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Max Ray Glossy

The Max Ray Glossy parameter is using the maximum number of reflections of rays with the glossy (shiny) surface in the ray-tracing rendering method. The glossy surfaces are the ones that have shiny properties, i.e. glass, metal or a smooth paint. When a ray of light reaches such a surface, it doesn’t exactly reflect in one direction. Instead, it scatters to some degree, creating a shiny or reflective effect.

This parameter defines how many times the rays can reflect off of the glossy surfaces. For instance, if the value is set at 2, it means that the ray of light can reflect off of the glossy surfaces up to two times, creating double or multiple reflections as in a mirror. Increasing the value of this parameter can make the gloss and reflections appear more detailed, which in turn makes the materials look more realistic. Keep in mind that, just like the previous two ray-tracing settings, increasing the value of Max Ray Glossy can significantly increase the time of the rendering, especially for complex scenes with a great number of glossy surfaces. That is why, once again, you might want to consider finding a compromise between the quality of rendering and the time consumed to render the scene. The default value of this parameter is 5, which is the value we normally recommend.

Max Ray Refraction

Max Ray Refraction (i.e., the maximum number of refraction rays) controls the maximum number of the refracted rays when using the ray-tracing rendering method. Refraction occurs when a ray of light passes from one environment to another with different refractive indexes (the refractive index determines how much the light is bent while passing from one environment to another). Glass, water, ice and other transparent materials can serve as examples of refraction.

This parameter determines how many times a ray of light can be refracted when it passes through different transparent materials in the scene. For example, if the value of Max Ray Refraction is set to 2, it means that the ray of light can refract up to two times while it passes through the transparent objects, creating an effect of lens or distortion.

Increasing this parameter can make the rendered scene more realistic, especially if the complex transparent objects are present in it. But, similarly to other ray-tracing settings, increasing this parameter inevitably leads to additional calculation resources. In order to choose the optimal value of Max Ray Refraction, you need to consider the project’s requirements and the level of detail that you want to achieve in rendering transparent objects. You can use the default value of Max Ray Refraction, which is 5. Experiment with this parameter and evaluate its influence on the quality of the rendered image and the time spent on rendering to find the perfect balance.

Max Ray Shadow

The Max Ray Shadow parameter determines the maximum number of rays that are used for the shadows calculation in the ray-tracing rendering method.

The shadows are created by tracing the rays from the light source to the surface of objects. A certain point is in the shadow when a ray of light can’t reach said point on the surface because of an obstacle. For more realistic results, specifically for the softer shadows or the shadows from transparent objects, several rays are required to define the intensity and the shapes of the shadows.

You can increase this parameter if there are many objects in the scene that overlap and cast shadows on top of one another (for example, a glass casting shadows on a tree and both of these objects casting shadows on water). Increasing the value of Max Ray Shadow leads to achieving shadows that look softer and more realistic, particularly in complex scenes with different light sources and obstacles.

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Ray Cast Epsilon

Ray Cast Epsilon (the max epsilon value for rays) controls the maximum epsilon value for determining the intersection of the rays in the ray-tracing rendering method.

Epsilon is a small numerical value used in calculations with a floating point to compensate for rounding errors and achieving accuracy. In rendering, epsilon is used to define when a ray of light passes the surface of an object.

Ray Cast Epsilon determines the maximum epsilon value for the rays that are used in calculations of ray intersection with the surfaces of objects. Increasing the value of this parameter can be useful to avoid issues with the accuracy of the intersection of rays and surfaces, especially in the scenes with the smaller objects or the objects that are close to one another. On the flip side, increasing Ray Cast Epsilon can also cause more false intersections of rays and objects, which leads to unexpected errors in rendering.

We recommend working with this parameter only if you are experiencing issues with the accuracy of intersection of rays and objects in your scene. Otherwise, it is better to use the default settings (value) of Ray Cast Epsilon.

Clamp Radiance

Clamp Radiance allows you to limit the brightness or intensity of light when rendering. If the scene contains light sources such as lamps or the sun, the intensity of light can be extremely high, particularly in spots where the light directly strikes the surface. This can cause bright light patches and the effect of overexposure, resulting in an unnatural and distorted rendered image.

This parameter controls the maximum intensity of light, preventing overexposure and unwanted bright patches of light. When you set a certain value of Clamp Radiance, the light that exceeds the maximum value of intensity is limited and reduced in order to meet the maximum value.

Restricting the exposure can be useful in achieving more realistic and eye-pleasing images, but setting the value of this parameter too low can cause a loss of detail in the light-to-dark transitions or create excessively dark areas in the rendered image. The appropriate value of Clamp Radiance depends on the properties of the scene and the specific traits of light sources. We recommend starting with a lower value and gradually increasing it until the desired result is achieved. Experiment with this parameter to find the optimal value for your particular project and scene.

Adaptive Sampling, Noise Threshold, Half-Precision Math and Filters

As we have already mentioned, sampling is used to reduce noise in the rendered scene. It can be adaptive or fixed. Sometimes, the noise level becomes acceptable even before all samples are taken. In this case, further sampling doesn't make any significant improvement, so the rendering can be stopped. Since images tend to have regions with different noise levels, we recommend using the Adaptive Sampling mode in most cases. In this mode, noisier regions are identified and have more sampling iterations. Sampling stops in areas where the level of noise is below the Noise Threshold value.

Decreasing the Noise Threshold also helps to fight noise in the rendered image. Setting this parameter to zero is equivalent to using the Fixed Sampling mode, which is the same as switching off the Adaptive Sampling. The Fixed Sampling mode can be used with images that have similar levels of noise in all areas. The number of samples in this mode is defined by the Render Samples parameter.

The Half-Precision Math option saves memory and improves performance at the expense of slightly reduced quality of the rendered image. You can activate this parameter if you need to render a quick sample image as a test, but if you want to achieve a large, detailed and highly-realistic result, we do not recommend using Half-Precision Math.

If you want to learn more about the Denoise, Tonemap and other Filters, check out another article about working with AMD Radeon™ ProRender on our website.