New features in 4D version 2.09 GLASS2 SA4D v2.09 adds a new texture that simulates solid glass, that is, glass with thickness. This texture, Glass2, is identical to the Glass texture with one exception, the thickness of the glass allows the property known as the index of refraction to be considered when generating images. Technically speaking: -------------------- Refraction, or bending of a light wave, is caused by wavelength of light changing speed as it passes from one medium to another. Light travels more slowly through a dense medium than it does through a less dense medium. So, if the surface defining border of the two mediums is encountered at an angle, the portion of the wave of light is retarded in the dense medium while the portion left in the less dense medium continues to travel at the same speed. This causes the direction of the light to change slightly. With parallel surfaces, the refraction angle from a less dense medium (air) to a more dense medium (glass) is counteractedby the refraction from the more dense to the less dense. The other factor in volved is the thickness the slice of glass. The thicker the plane the greater the image shift. With almost zero thickness between the two planes, the image shifts imperceptibly. Actually, each face of the original Glass texture could be considered to be two, equally sized, connected faces of Glass2 lying absolutely parallel to each other and infinitely close to one another. Parallel faces cause ray's direction to be corrected and the lack of thickness does not allow an image shift. Restrictions: ------------ Glass2 objects MUST be closed solid objects. Single faces will produce unpredictable results. (If you want to produce a glass bottle, the bottle's sides should have an inside and an outside wall joined at the top with a rim.) CSG spheres The Constructive Solid Geometry (CSG) sphere is a new object primitive in SA4D. Technically, this type of object can be described in terms of the parameters of a simple mathematical formulae. In the case of a sphere, it is described by a point in three dimensional space and a radius. What this means to you as a modeler is that a CSG object renders more quickly than the same object approximated with a number of triangular faces. In fact, the nearest approximation used for a sphere in Sculpt Animate is a '2 subdivision sphere'. A '2 subdivision sphere' is constructed of 320 triangular faces. Since CSG spheres are mathematically considered as only 1 face, the CSG sphere can be rendered in as little as 1/320th the time! You may be wondering why, if CSG spheres are so much better, the Sculpt family of products hasn't included CSG objects all along. Even though Dr. Graham's original 'Juggler' was constructed completely of CSG spheres, we had not been able to gracefully integrate the function into concepts of the Tri-View. This, plus the inherent limitations of CSG objects, convinced us to not include the option. However, in response to the constant bombardment of requests for the capability, it is included in this new version. What are the drawbacks and limitations of CSG spheres? Well, first of all, this object is considered to be a single face. This means that you cannot have a half red and half blue CSG sphere that is shiny on one side and mirrored on the other. Any modification to a part of the sphere affects the entire sphere. Secondly, the inclusion of the object has required some compromises in the Tri-View concepts. The CSG object appears as a zero sub- division, or twenty face, sphere in the editor. This is to allow all the vertex, edge, and face based editing tools to be used to modify the CSG object. The CSG sphere may be modified as if it were any other Tri-View object, but as long as the original edges and vertices remain intact, the CSG property is retained. Additionally, since only ray-tracing modes can take advantage of the shading operations of a single face object, only the Snapshot and Photo modes show CSG objects. All other rendering modes also display CSG spheres as zero subdivsion spheres. Think of trying to display as a single face in a wire frame or polygonally shaded mode. Such a display would show what would appear to be a two dimensional disk. This would be clearly unacceptable. How to create a CSG sphere ---------------------------------- When the Add Sphere menu command is called from the Edit menu, you may tell the program to add a sphere with -1 (negative one) subdivisions. This enables the CSG capability. The object added will appear to be a 0 sub-division sphere in all modes except Photo and Snapshot. Modifying a CSG sphere ------------------------------ Any change in the attributes of the CSG sphere should be preceded by selecting the entire sphere with the 'Select connected vertices' command from the Edit menu. The position and radius of the CSG sphere is taken from the position of its centroid and the average of the distances of the 12 component vertices from the centroid. While this means that individual vertices of the objects may be moved without destroying the sphere, it also means that moving or resizing individual portions rather than the whole sphere can make interpreting the position and size of the CSG sphere difficult or impossible. The CSG property will be lost if an edge or vertex is erased or added. Subdividing CSG spheres also demotes the object to a sphere. The CSG property may be saved to and loaded from scene files. It may be duplicated and the duplicated object will also be a CSG sphere with all the same attributes. All faces of the icosahedron will have the same color and texture. This color or texture will be the last set on ANY of the faces of the sphere. [Note to programmers: please notice the new 'CSGE' chunk in the file format.] Splines Individual knots of a spline that are linked as offspring of paths cause the spline to be recalculated during each successive frame of animation. This allows serpentine motion to be created almost fully automatically. Duplicate Spline and path attributes are now duplicated along with the edge and vertex information. Reflecting objects Note that the spline and path attributes of a curve will only be reflected if all the vertices lie away from the plane of reflection. This is to say, if any of the selected paths or splines have portions to the left AND right of the position of the cursor in the active window, the object that is created by reflection will be demoted to a simple curve. Likewise, if a vertex of the spline or path lies in the same vertical line as the cursor in the active window, that reflected object will be demoted to a simple curve. ANIM-5 ANIM op-code 5 is supported for compression and playback. This file format should be compatible with other Amiga animation and control packages. While SA4D supports NONE, OSCILLATE, & LOOP mode playbacks, ANIM-5 supports LOOP mode only. ANIM-5 is a fast compression scheme but does not support as high a playback rate as Sculpt Animate's proprietary 'Movie' format. Please be aware that many animation and control packages do not support image sizes other than regular screen size. This means that they may only support FULL sized animations. Packages that support overscan animation should be able to support JUMBO sized animations but not severe overscan sized VIDEO animations. Other improvements If an image render is interupted (through the Abort command or with a Cntrl-C) the partial image is not automatically unloaded. Partial images may be saved to disk. The 1/10 modifier key now works while modifying the indicated tumble. Feedback in the take on carryover settings of duration, image, scene, and animation drawers has been improved. Background and Foreground rendering has been overhauled. The Cancel gadget on the 'Word from the manual' requestor now causes the program to shut down. Mirror, Glass, and Glass2 reflect the colors of a graduated sky when the Sky is set to NONE. (This is to extend background and foreground rendering capabilities.) SA4D 2.09 can show a 10% speed increase in rendering. Memory availability checking has been reinforced. The program also checks upon startup to see if sufficient Stack has been allocated. Additional clipping and display error handling have been added to the Hide and Reveal functions. The Erase All function has been impoved and accelerated. The Display early/late toggle is now reversible. Movie 2.0 ANIM-5 ANIM op-code 5 is supported for playback. ANIM5 uses LOOP mode only. Video size anims Video size is now supported for playback. Please note that VIDEO sized animations may require more chip memory than Amigas without the Enhanced Chip Set (ECS) have available. Those users with the ECS should verify that the extra chip memory has been made available with the proper options set through Commodore-Amiga's 1.3 SetPatch command.