Reference Guide
Reference Guide
Reference Guide

Rendering Settings dialog box

Controls the display of curved surfaces and pattern maps, shadows (Phong rendering only) and Distance Cueing. Opens when Settings > Rendering > General is chosen.

Rendering Settings dialog box


Stroke Tolerance (pixels)

When a 3D model is rendered, the model is divided into polygons (in memory), with curved surfaces being represented by a polygon mesh. Stroke Tolerance determines the size of these polygons, which directly affects the accuracy of curved surfaces displayed in the shaded image. This is most apparent at the edges of curved objects.

Effect of Stroke Tolerance — large.


Effect of Stroke Tolerance — small.


The Stroke Tolerance is the maximum distance (in pixels) a surface can deviate from the polygons used to render it. Stroke Tolerance can be from 0.001–1000.00, with smaller settings providing more accurate representation of curved surfaces, at the cost of longer rendering time. For most rendering, the default of 0.500 provides excellent results. For some images you may need to use a smaller setting.

Override (mu)

If on, this setting lets you override the Stroke Tolerance setting. When the Override toggle is selected, the associated value is the maximum distance (in working units) a surface can deviate from the polygons used to render it. This is very useful when you are creating a view independent solution, such as Ray Tracing with Render All Objects enabled, or generating a radiosity or particle tracing solution. For example, there are certain times when the view is set up in such a way that when the camera is temporarily disabled (during the creation of the rendering database) the design would appear very small within the view. Under these circumstances, the solution might appear extremely rough. You can overcome this anomaly by setting the Stroke Tolerance Override in working units.

This setting has no effect whatsoever for the other Render Modes, or when ray tracing with Render all Objects disabled.

Antialiasing Quality

Used to set the grid size used during antialiasing calculations. Choosing from any of the preset options — Very Low, Low, Medium, High, Very High — automatically sets the values for Antialiasing Grid Size. Choosing Custom lets you manually edit the Antialiasing Grid Size value. This setting is that is present in the Antialiasing Settings section of the Ray Tracing dialog box.

Antialiasing Grid Size

When a design is rendered antialiased, in Constant, Smooth, or Phong render mode, the image is rendered in several passes. In each pass the image is shifted slightly in the X and Y directions. Each of the resulting images is averaged to create a single antialiased image. The number of passes in each direction is determined by the antialiasing grid. If set to 2, for example, the system will antialias on a 2x2 grid using 4 passes; if set to 3, it will use 9 passes. The higher the value used, the more passes will be taken, and the higher the quality of the image will be. This value is set automatically when you choose an Antialiasing Quality setting and is not editable unless you choose Custom.

For ray tracing, antialiasing is controlled in the More Ray Tracer Settings dialog box.

Phong Shadow Filter Size

Determines the softness of shadows for Phong rendering (only); a higher value produces softer shadows. Its value describes the number of adjacent pixels to look at in the shadow map:

Phong Shadow Tolerance

Determines how close objects can be to cast shadows on each other in Phong rendering (only), and is used to prevent surfaces from casting shadows on themselves. It is specified as a proportion of the maximum distance from the light to an element.

The default value .02 is usually sufficient to prevent self-shadowing. Large Shadow Tolerance values can cause inaccurate shadow generation.

If the shadow tolerance is too large, objects may not cast shadows on other objects that are too close. If it is too small, the objects might shadow themselves, causing a rippled appearance across the surface.

Multi-level Texture Interpolation

Multi-level Texture Interpolation is a texture mapping option for Phong and ray traced rendering that provides less noisy images and smoother animations. When this option is enabled, each texture map and bump map is pre-filtered into a series of successively lower resolution maps when it is referenced for the first time.

When a pixel from the texture map is needed, pixels from the two pre-filtered images of the size closest to the needed size are interpolated to determine a pixel value. This provides a less noisy appearance when the texture is scaled down, and a much smoother transition of pixel values as the size of the texture changes on screen during an animation.

With Multi-level Texture Interpolation turned off, the image appears “noisy.”


With Multi-level Texture Interpolation turned on, the grass material in particular diminishes naturally in the distance.


Interpolate Textures

If on, surface color is extracted from the pattern image by interpolating between the two closest pixels. In most cases, this produces the best results, although it may be undesirable in certain instances.

Save Phong Shadow Maps

If on, shadow maps, generated in Phong rendering, are saved the first time that a design is rendered. This results in reduced times for future rendering. Subsequent rendering of the design uses the saved shadow maps, rather than re-creating them.

Names for shadow map files are based on the order of the lights and the name of the design file. For the design file “test3d.dgn,” the shadow maps will be “test3d.l01”, “test3d.l02,” etc. (where l is for light).

If a light is moved using the controls in the Source Lighting settings box, making its shadow map invalid, the shadow map is recalculated automatically. The Source Lighting dialog box is opened by choosing Rendering > Source Lighting from the Settings menu.

Ignore Open Elements And Text

If on, the Ignore Open Elements And Text setting restricts rendering processes to only those elements that include an area component: surfaces and all closed elements such as shapes, ellipses, and complex shapes. Conversely, all open elements, such as lines, arcs, text, and points, are not rendered (and therefore not displayed in rendered images).

Log Rendering Statistics

If on, rendering statistics are stored in the render.log file. This log file is configured via the MS_RENDERLOG configuration variable. The default is $(MS_IMAGEOUT)render.log and is defined in appl/zmptools.cfg.