Creating Planets (with RISC OS)
Recent scientific discoveries indicate that two of our closet planets have outer rings of bright blue. The rings of Uranus and Saturn contain tiny dust particles that scatter and reflect blue light. This provided a stimulus for my interpretation of the picture you see here.
ArtWorks, with its ability to create bands in a circle (figure 2), seemed the obvious choice. This feature rich package provides the user with the tools necessary to produce a picture with some degree of realism. The main difficulty is designing the ringed planet and this is what my article explains.
Summary of Main Techniques Used to Create the Blue Planet
The Intersect Tool
This ingenious tool was used to create the blue planet. It takes a little practice to get the best out of it but once mastered some remarkable artistic creations are possible. The example below will be illustrated in colour for clarity.
Before starting decide how many colour bands are required (the example below uses 4 separate bands apart from the main blue crescent which forms the base layer).
Fig 3 Coloured bands created with the aid of the Intersect tool
Performing the Intersect
By applying more subtle colouring the procedure can be used to draw the planet illustrated in figure 2.
Making the planet stand out
By adding a linear gradient across each coloured band should give the planet a more 3-dimensional feel when added to the final picture. The linear-fill gradient tool is used here to create this effect starting from say.....70% black on the left hand side to the selected band colour.
Linking the Planet to the Background
Dropping the completed planet object over a black background produces an unrealistic effect. A more subtle approach was used to ensure the colours integrate seamlessly into the background - my method being to use the blend tool to create a group of concentric circles from white to black around the planet circumference. The blend tool is described in the next section.
Creating the Planetary Rings
Only the outer ring needs describing in detail and consists simply of a dual blend between three ellipses. The procedure is as follows:
Select the objects (planet and rings) and use ArtWorks alignment tool (CTRL-F9) to centre align them as shown in figure 8.
Hiding the Furthest Rings Behind the Planet
It is important that the far rings disappear behind the planet. I will leave the reader to decide how this is achieved (hint - it's a bit like fitting a cloned 'cap' of the planet to itself and ensuring that it resides on the top layer stack to hide the far rings). Group all objects and drag to a prepared 'black canvas' and rotate accordingly.
Those who have attempted the tutorial will immediately see what an excellent user interface ArtWorks presents to even a beginner. Regular users will already be aware how easy the program makes it to create quite complex graphic images.
See you in two months time with some more simple ArtWorks projects.
Further Addendum to Article 1
My first article (CDROM magazine - October 2007 - Volume 8, Issue 3) demonstrated how Photodesk could be used to create simple kaleidoscopes. I was very enthusiastic about a new version (Photodesk, version 3.08) released and sold by CJE - because the programmer (Niklaus Weiss) had re-written the selection routines to run significantly faster on the Iyonix. There is no doubt that the selection process is noticeably faster but sadly I have to report that the software reliability is extremely poor compared to its predecessor. My recommendation is to stay with version 3.06 for the moment. There are some work-arounds to speed up selections/drags and I may discuss these in future articles.