In addition to rendering to the 3ds Max Rendered Frame Window (RFW or VFB), V-Ray allows you to render to a V-Ray specific frame buffer, which has some additional capabilities:
- Allows you to view all render elements in a single window and switch between them easily;
- Keeps the image in full 32-bit floating-point format;
- Allows you to perform simple color corrections on the rendered image;
- Allows you to choose the order in which the buckets are rendered.
The V-Ray VFB also has some limitations, which are listed in the Notes section below.
Show last VFB - If you have rendered to the V-Ray VFB, but have closed it, this button allows you to open it again. The same can also be achieved with the showLastVFB() MaxScript method of the V-Ray renderer.
Enable built-in frame buffer - Enables the use of built-in V-Ray frame buffer. Due to technical reasons, the original 3ds Max frame buffer still exists and is being created. However, when this feature is turned on - V-Ray will not render any data to the 3ds Max frame buffer. In order to preserve memory consumption we recommend that you set the original 3ds Max resolution to a very low value (like 100x100) and turn off the 3ds Max Virtual Frame Buffer from the common 3ds Max render settings.
Render to memory frame buffer - this will create a V-Ray frame buffer and will use it to store color data that you can observe while rendering and afterwards. If you wish to render really high resolutions that would not fit into memory or that may eat up a lot of your RAM not allowing for the scene to render properly - you can turn this feature off and use only Render to V-Ray raw image file feature.
Get resolution from 3ds Max - this will cause the V-Ray VFB to take its resolution from the 3ds Max common render settings.
Output resolution - this is the resolution that you wish to use with the V-Ray frame buffer.
Pixel aspect - specifies the pixel aspect for the rendered image in the V-Ray frame buffer.
Render to V-Ray raw image file - when this is on, V-Ray directly writes to disk the raw image data as it is being rendered. It does not store any data in the RAM, so this feature is very handy when rendering huge resolutions for preserving memory. If you wish to see what is being rendered, you can turn on the Generate preview setting. You can specify either a .vrimg or an .exr file for output:
- If you specify a .vrimg extension, the resulting file can be viewed through the File > View image... menu of 3ds Max, or converted to an OpenEXR file with the help of the vrimg2exr tool.
- If you specify an .exr extension, V-Ray will write out a tiled OpenEXR file that can be used directly by 3ds Max or other compositing applications. The file contains all render elements for the image.
Generate preview - this will create a small preview of what is being rendered. If you are not using the V-Ray memory frame buffer for conserving memory (i.e. Render to memory frame buffer is off), you can use this feature to see a small image of what is being actually rendered and stop the renderer if there is anything that looks wrong.
Save separate render channels - this option allows you to save the channels from the VFB into separate files. Use the button to specify the file. This option is available only when rendering to a memory frame buffer. If rendering is done only to a raw image file, the render channels can be extracted from that file after rendering is complete.
Save RGB and Save Alpha - these options allow you to disable saving of the RGB and Alpha channels respectively. This can be useful if you only want to generate other render channels. Note that V-Ray will still generate the RGB and Alpha channels, however they will not be saved.
There are some additional parameters of the VFB, which are not available in the interface, but are accessible through MaxScript. These may be useful in certain situations. Below are listed the MaxScript names of these parameters.
output_renderType - This allows you to override the render type, specified in the 3ds Max settings. Possible values are:
0 - use 3ds Max render type (default);
1 - render the full image;
2 - region rendering;
3 - crop rendering;
4 - blow-up rendering.
output_regxmin - The left coordinate (in pixels) of the region to render (for region/crop/blow-up rendering);
output_regxmax - The right coordinate (in pixels) of the region to render (for region/drop/blow-up rendering);
output_regymin - The top coordinate (in pixels) of the region to render (for region/drop/blow-up rendering);
output_regymax - The bottom coordinate (in pixels) of the region to render (for region/drop/blow-up rendering);