Use Camera Path – When enabled, V-Ray calculates the GI samples for the entire camera path instead of just the current view. For more information, see the Retrace Parameter example below. Note that this option may increase the render time. For glossy reflections and refractions, V-Ray dynamically decides whether to use the light cache or not based on the surface glossiness and the distance from it so that the errors due to the light cache are minimized. This is especially obvious with the Use light cache for glossy rays option, or near corners where light leaks might be possible because of the light cache interpolation. Retrace – Improves the precision of the global illumination in cases where the light cache will produce too large an error. This value might work better for fly-through animations, since it forces constant sample density everywhere. This can affect the quality of the samples - samples that are close to the camera are sampled more often and appear smoother, while samples that are far away are noisier. World Units – The sizes are fixed in world units everywhere. This value is best suited for stills or animations where the light cache needs to be computed at each frame. Note that the units do not depend on the image resolution. Samples that are closer to the camera are smaller, and samples that are far away are larger. Screen Space – The units are fractions of the final image (a value of 1.0 means the samples are as large as the whole image). For more information, see the Sample Size Parameter examplebelow. This value can be either in world units or relative to the image size. Larger numbers smooth out the light cache but loose detail.

Smaller numbers mean that the samples are closer to each other, the light cache preserves sharp details in lighting, but it is more noisy and takes more memory. Sample Size – Determines the spacing of the samples in the light cache. For more information, see the Subdivisions Parameter example below. The actual number of paths is the square of the subdivisions (the default 1000 subdivs mean that 1 000 000 paths will be traced from the camera). Subdivs – Determines how many paths are traced from the camera. These parameters affect the calculation phase of the light cache they do not affect the final rendering.

Light settings rhino render