Render

Basic

Resolution and antialiasing

Use viewport resolution

Renders the active viewport the active viewport using the pixel size of the viewport.

Use custom resolution

Renders the active viewport using the custom resolution. Type the custom width and height resolution in pixels.

Size

Calculates the size of the image in the selected unit system based on the Resolution and DPI settings. This is useful for determining the size of the image for printing.

DPI

Image pixels ("dots") per inch.

Antialiasing

A method of smoothing the jagged edges along the lines and curves of text or graphics. This is done by a mathematical process that super samples pixels. Aliasing is caused by limited display resolution. Aliasing effects include stair-stepping along diagonal lines and moiré effects in checkerboards. Rhino calculates each pixel in the rendered image by averaging several samples taken from the pixel area. This makes the image appear smoother, but also slows down rendering.

None

Normal (2x)

Medium (5x)

High (10x)

Ambient light

Color

Sets the color of the darkest spot on the objects in the scene in the rendered image. The color of the low light areas of the model is a blend of the object color and the ambient light color.

Bottom color

Sets a different color for the lower area.

Use bottom color

Turns usage of the Bottom color setting on.

Background

The background is what you see directly in front of the camera if there are no objects in the way. The background is not 3‑D — it exists only on the screen.

Solid color

Displays a solid color.

Gradient

Displays a two-color gradient.

Environment

Displays the portion of the current environment that the camera sees in the viewport.

Wallpaper

Displays the current viewport wallpaper.

Transparent background

The background is rendered with an alpha channel for transparency. The image must be saved to a file format that supports alpha channel transparency (.png, .tga, .tif).

Skylight

Turns on skylight.

Miscellaneous

Use lights on layers that are off

Controls whether or not spotlights that are on hidden layers or that are hidden with the Hide command are rendered.

Render curves

Curve objects are rendered with the surfaces.

Render surface edges and isocurves

Surface isoparametric curves and edges are rendered with the surfaces.

Render dimensions and text

Dimensions and texts are rendered with the surfaces.

Advanced Rhino Render Settings

Render acceleration grids

Screen grid, cell size: ___ pixels

The width and height of each grid cell in pixels.

The smaller the grid cell size, the more memory it takes and the more memory it takes to build, but the faster the final render.

Spotlight shadow grid, size

The shadow ray is the ray shot from the scene towards each light when the intersection between the eye ray and the scene is found. Usually the lions share of the render time is spent tracing the shadow rays.

To increase calculation speed for the spotlight shadow rays, the render plug-in divides the spotlight cone into rectangular regions, and again builds a sorted list of the objects within each region. This speed increase only applies to spotlights, because they are very similar to the viewports, the light location is like the camera location, and the light cone defines the viewport.

The spotlight grid is defined in number of grid cells instead of pixels, because there is no pixel size associated with lights.

Preventing self-shadowing

Prevents self-shadowing artifacts. When the intersection between the eye ray and the scene is found, the intersection point is moved (offset) towards each light before calculating the shadow ray. The reason is there's always some numerical fuzz in calculating the intersections, and if the point is not offset, the shadow ray might hit the very same polygon again, putting shadows in wrong places. You can see the self shadowing artifacts if you set the setting to zero, and then render the scene.

Ray offset

The amount of offset.

Object & polygon bounding volume hierarchy

A binary space partitioning (BSP) tree is another way to increase rendering speed. Instead of testing each polygon one-by-one, the objects and polygons are divided into a tree-like hierarchy based on the location in space.

The renderer builds multiple trees, one that contains the whole object bounding boxes, and one per object that contains the polygons for that object.

The BSP tree takes some time to build and takes some memory. A deeper tree may take longer to build, but may renders faster. A shallow tree is faster to build, but may take a long time to render.

Max tree depth

Controls how many times the scene can be subdivided when building the tree.

The tree depth defaults to Auto, and node size to 1. There should be no need to change these settings unless you render a scene that is so huge that Rhino runs out of memory using the default settings.

Target node size ___ (objects/polygons)

Defines the optimal size for each node that contains the objects or polygons.

Transparency

Maximum number of bounces

The transparency bounces setting controls how many times rays that hit transparent objects are traced: 12 means a stack of 12 transparent sheets will render properly, but the 13th sheet will render opaque. To keep the render times reasonable, the limit is 15.

Reflectivity gradient

Maximum number of bounces

The reflectivity bounces setting controls how many times rays that hit reflective objects are traced. To keep the render times reasonable, the limit is 15.

Perspective camera focal blur

These settings control the slow but more accurate focal blur that is generated by shooting more rays into the scene.

No focal blur

Autofocus on selected objects

Adjusts the focal distance and aperture automatically so that selected objects are rendered sharp.

Manual focus