When AccuRender begins a rendering, it has to allocate a large block of memory to hold the finished image. If the rendering you are attempting is big enough, Windows may not be able to allocate that much RAM. AccuRender 4 will then print the error message Raytracing failed - Error Code -2.
The amount of memory required by AccuRender depends on which image channels it is writing. By default, AccuRender will write 3 color channels, luminance data, a distance channel, material ID channel and an alpha channel.
The last 3 (distance channel, material ID channel and an alpha channel) can be turned off on the Render Settings dialog to save on the total memory requirement.
If you need to render an image and AccuRender reports that it is out of memory when you press the Render button, please turn off the Distance, Material ID and Alpha channels and try again.
Note: The total amount of RAM available to AccuRender is limited by Windows at 2Gb - it doesn't matter how much physical RAM you have in your computer.
Note: AR3 did not render distance and material ID channels and so was able to render larger images by default. However, AR3 did not have the option to turn off the Alpha channel, so AccuRender 4 is able to render larger images than AR3 with this option unchecked.