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There are 3 parameters that can be set for each camera: Field of View This is the vertical angle that the camera can 'see'. The field of view can range from 0 to 180 degrees. The horizontal field of view is determined by the aspect ratio of the image. Some interesting effects can be created by varying this parameter. The examples below were created by varying the field of view and zooming in on the object: ![]() |
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On the left is a list showing the camera filters that are available. Currently there are 7 filters
to choose from. To apply a filter, select it in the list and click on Add>>. This adds a filter
of the selected type to the right hand list. Filters in the list are applied to the image in a top
down order. You can have as many filters as you like in the list and their order can be altered using
the Move Up and Move Down buttons. Filters can also be deleted via the Delete
button. Selecting filters in the right hand list displays their adjustable parameters in the panel beneath. For example, the Glow filter's parameters are Radius, Intensity and Shape. On the right of the dialogue is a preview of the rendered image. The rendering parameters for this preview can be selected by clicking on Configure Preview which brings up the a dialogue with most of the usual rendering options. |
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Ambient Color defines the colour and intensity of light falling on every surface, not coming
from any particular source but from every direction equally. Environment This sets the background which can either be a colour or a texture. To select a colour, select Solid Color from the drop down menu and click on the colour bar beneath this menu to select a colour. To set a texture, select Texture Diffuse or Texture Emissive from the menu. Click on ![]() |
Environment Fog produces a uniform fog effect. The Fog Color defines the colour of the fog
using the usual colour chooser. The amount of light getting through to the camera from a point at a
distance r from the camera is given by e -r/d where d is the Fog
Distance. Objects much closer to the camera than d will be relatively unobscured by the fog.
The best effects are obtained with the fog colour similar to the Environment colour. |
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The Width and Height define the size (in pixels) of the 2D image created. The Camera selected defines which view will be rendered. The view can be previewed by selecting the relevant camera in one of the view windows and ensuring that the zoom is set to 100. You can select whether to render a Single Image or a Movie. The Movie option actually produces a series of consecutively-numbered images which can be converted to a video format by many available graphics packages. See animation for more details on rendering movies. The next set of boxes, i.e. Start Time, End Time, Frames/Sec and Images/Frame are all related to animation. Refer to that section for details. |
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Texture Smoothing applies antialiasing to all textures in the scene to remove details smaller
than a pixel to overcome problems that can arise with under- or over-smoothing in the renderer or texture.
A value of 1 is the default amount of smoothing. Values greater than 1 do more smoothing and values less
than 1 do less. Reduce Accuracy for Distant Objects If this is checked then objects further away in the scene have a lower surface accuracy than those that are near. This provides optimum performance with very little noticeable difference in quality of output. Eliminate backfaces The triangles drawn by the raster engine have a front and a back. Normally the backfaces are not seen and the render can optimise performance by not drawing them. On some occasions, however, e.g. inside closed objects, the backfaces will be seen and this option will need be to be unchecked. |
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The Width and Height define the size (in pixels) of the 2D image created. The Camera selected defines which view will be rendered. The view can be previewed by selecting the relevant camera in one of the view windows and ensuring that the zoom is set to 100. You can select whether to render a Single Image or a Movie. The Movie option produces either a series of consecutively-numbered images (which can be converted to a video format by many available graphics packages) or a Quicktime movie . See animation for more details on rendering movies. The next set of boxes, i.e. Start Time, End Time, Frames/Sec and Images/Frame are all related to animation. Refer to that section for details. |
This technique is very effective for simulating the lighting produced on an overcast day (as in the example below) or an interior scene with large overhead light sources. | Also, using GI, emissive textures really do give out light. The light emitted can be increased by using the colour Scale module to scale the object's emissive colour. See here for details. |
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To understand some of the options available here, we need to consider the raytracing process. The engine
sends a ray from the camera through each pixel in the image and looks for interactions with objects along
the way. If it hits a shiny or transparent object, it sends out more rays which, in turn, may lead to further
rays etc. This produces a 'tree' of rays resulting from the single initial ray which could go on for ever. In order to stop the process at a sensible point, there are 2 parameters: Max Ray Tree Depth which is the number of levels produced from the initial ray, and Min Ray Intensity which stops the process once the intensity of the rays becomes small enough as to have a negligible contribution to the final colour of the pixel. These parameters, then, are ways of balancing the rendering time and rendering quality. You will need to increase the Max Ray Tree Depth if there are a large number of reflections or transparent objects. In the example below, a red cylinder is placed between 2 parallel mirrors which should produce an infinite number of reflections. In this situation, the Max Ray Tree Depth needs to be increased as shown. |
Standard raytracer - render time 12m 46s | Russian Roulette Sampling - render time 10m 01s |
Transparent Background This produces an image with a background that is transparent, i.e. it adds
an alpha channel to the image (if saved in .tif or .bmp format). A 2D paint program should then allow a
selection to be made using the alpha channel. Generate High Dynamic Range Image. If this is turned off, then the pixel colours in the rendered image(s) are a combination of red, blue and green channels, each with a range of 0 - 255. This limits the range of intensities present in an image. Switching this option on, produces floating point pixel data in the rendered image instead, which effectively allows an infinite range of colours/intensities. This is only worth doing if the image format used to save the rendered image(s) supports floating point, i.e. .hdr. |
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Here you can select the image format to be saved, either JPEG (.jpg), TIFF (.tif), PNG (.png),
Windows bitmap(.bmp), or Radiance or High Dynamic Range Image (.hdr) files. If you have transparent
background, then you will need to save as a .tif, .bmp, .png file to retain this information to use,
for example, in a 2D graphics package. The Quality defines the amount of compression of the image when saved in JPEG format. A higher Quality value means a better looking image at the cost of file size. Clicking OK displays a further dialogue for the filename. |