Page History

This section covers common parameters for all sampler types. For parameters that are specific to each sampler, see the following sampler sections below.

Type – Specifies the image sampler type. Specific parameters for the selected type appear at the bottom of this rollout.

Progressive – Progressively samples the entire image. See the Progressive Sampler for additional parameters.
Bucket – Takes a variable number of samples per pixel depending on the difference in the intensity of the pixels. See the Bucket Sampler section for additional parameters. 

Render Mask – Enables the render mask feature. The render mask allows you to define which pixels of the image are calculated. The rest of the pixels are left intact. This feature works best with the V-Ray frame buffer and the Bucket image sampler. The following types are available:

Disable – The render mask is not used.
Object ID – Only objects with specified Object IDs are rendered, you can list more than one by using commas to separate them.

For more information, see the Render Mask example below.

Clear Mask on Render Stat – Available when the Render Mask is enabled. When disabled, the masked region is overlaid on top of the previous image in the VFB. This can be used for draft renders or fast shader previews provided that the camera does not move. Note: When rendering an animation, the image clearing is forced on.

Object IDs – Specifies a list of object IDs to be used for the render mask, when the Render mask is set to Object ID.

AA Filter Type – Specifies the filter type to be used for anti-aliasing. V-Ray supplies eight types of Anti-aliasing filters: Box, Area, Triangle, Lanczos, Sinc, Catmull-Rom, Gaussian and Cook Variable. Each has advantages and disadvantages, which make them useful for different tasks. For more information, see the Anti-aliasing Filters example and the Anti-aliasing Filters and Moire Effects example below.

Size – Determines the size of the filter in pixels. Higher values yield blurrier results.  For For more information, see the Anti-aliasing Filters example and the Anti-aliasing Filters and Moire Effects example below.

This section provides information specific to the Progressive Sampler Type. The Progressive sampler renders the entire image progressively in passes.

The advantage of this sampler is that you can see an image very quickly, and then let it refine for as long as necessary as additional passes are being computed. This is contrast to the bucket-based image samplers, where the image is not complete until the final bucket is done.

A disadvantage is that more data needs to be kept in memory, especially when working with render elements. Also, when using distributed rendering, because of the continuous refinement, frequent communication between the client machine and the render servers is required, which may reduce the CPU utilization on the render servers. This effect can be controlled to some extent using the Ray bundle size parameter.

Min Subdivs – Controls the minimum number of samples that each pixel in the image receives. The actual number of the samples is the square of the subdivs. Note: Not available when using a GPU-based Production engine.

Max Subdivs – Controls the maximum number of samples that each pixel in the image receives. The actual number of the samples is the square of the subdivs. If zero, the number of samples is not limited.

Noise Threshold – The desired noise level in the image. If this is 0.0, the entire image is sampled uniformly until either the Max. subdivs value is reached or the Render time limit is reached.

Max. Render Time (min) – The maximum render time in minutes. When this number of minutes is reached, the renderer stops. This is the render time for the whole frame; it includes any GI prepasses like light cache, irradiance map, etc. If this is 0.0, the render is not limited in time.

Ray Bundle Size (CPU) – Useful for distributed rendering to control the size of the chunk of work that is handed to each machine. When using distributed rendering, higher values may help to utilize CPUs on the render servers better.

Ray Bundle Size (GPU) – Controls the number of samples to transfer over the network for RT-GPU. Available when using RTX rendering. 

Rays Per Pixel – Controls the number of samples per pixel for RT-GPU. Available when using GPU/RTX rendering.

This section covers information specific to the Bucket Sampler Type.

This sampler makes a variable number of samples per pixel based on the difference in intensity between the pixel and its neighbors.

This is the preferred sampler for images with lots of small details (like Procedural Fur for example) and/or blurry effects (DOF, motion blur, glossy reflections, etc.).

The diagram above shows visually the way V-Ray is placing samples when using the Bucket sampler. The black squares represent the pixels of the image while the dots represent the individual samples. In the first pass V-Ray always places the minimum number of samples determined by the Min. subdivs parameter. Then the color of the samples is compared and more are added where needed in the following passes.

Lock Subdivs – Sets a fixed number of samples taken for each pixel.

Min Subdivs – Determines the initial (minimum) number of samples taken for each pixel. You will rarely need to set this to more than 1, except if unless you have very thin lines that are not captured correctly, or fast moving objects if you use when using motion blur. The actual number of samples is the square of this number (e.g. 4 subdivs produce 16 samples per pixel).

Max Subdivs – Determines the maximum number of samples for a pixel. The actual maximum number of samples is the square of this number (e.g. 4 subdivs produces a maximum of 16 samples). Note that V-Ray may take less than the maximum number of samples, if the difference in intensity of the neighboring pixels is small enough.

Threshold – The threshold that is used to determine if a pixel needs more samples. For more information, see The Threshold Parameter example below.