Computerworld 1996 March

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Welcome to Genesis beta v1.0 (c) Silicon Dream Ltd. 1995 It is important that you read at least the QUICK START section of this document before unzipping and running Genesis. I apologise for the poor format of the user documentation (yes, its what your reading now) and my spelling. The programmer documentation is far more proffessional and is included in the genvxx.zip file in both Microsoft Word format and plain text. Contents of this document: A BRIEF RUNDOWN PC REQUIREMENTS QUICK START THE USER GUIDE THE VIEW THE 3D CURSOR CHANGING VIEWPOINT SURFACE DIALOG TOOLS Sphere tool Patch tool Spin tools Diff, Union and Int tools Enclosed tool Coordinate system editor Normal tool ROYALTIES ON API USEAGE DEVELOPERS NOTE If you have any questions, queries, praises or verbal abuse then I am your primary and only point of contact; Name: Steven Woodman (otheriwse known as Spike) Org: Silicon Dream Ltd. Email: spike@silicond.demon.co.uk Smail-mail: Flat 1 Chine view, 5 Mckinley rd, Westbourne, Bournemouth, Dorset, UK, BH4 8AG Tel: ...ooooh - could be a bad idea Updates from: - The SimTel20 windows software repository - UK's Demon ftp server - The Raytech bulletin board on UK tel; 01862 832020 - Me Those of you who followed my original append in the comp.graphics.algorithms and comp.graphics.raytracing newsgroups will already be familiar with what Genesis is. To those who didn't here's a brief rundown; A BRIEF RUNDOWN Genesis is a new windows based 3D toolkit with a comprehensive set of programming interfaces. The editor application supplied as part of Genesis is intended to allow easy and intuitive editing of 3D objects, textures, lights and animations. My design goal was to try and build something like a 2D drawing program, BUT IN 3D! The API can be used for writing 3D applications independent of the editor. On the other hand if you are interested in writing a 'tool' to do a 3D type job, for instance, say you want to write some code to take one 3D object and 'bend' it around another, then the way to do it is to write a 'tool' that plugs into the editor. The various API's provide you with an excellent platform to start your work, one in which most of the hard stuff is already done for you. The Geometry engine is also replaceable meaning Genesis could support BRender, Glint chips, Windows 3D GDI, Open GL, Renderware, Playstation, Rendermorphics engine and Intel 3DR to name but a few. PC REQUIREMENTS You need; * At least a 386 PC WITH a maths copro (or 486DX). Contact author for details of non-copro version * 4 Megs RAM although 8 is recomended * About 3 megs free on hard disk * Window 3.x * A good graphics card. The faster your graphics card the better. Also if your card supports true colour (either 16 bit or 24 bit), this will give better results than an 8 bit colour card. Check your card is in true color mode if it has one. QUICK START To get straight into the Genesis editor, do the following; Make a directory you want to install it in, eg; md gen copy the gen.zip file in, eg; cd gen copy \gen.zip unzip this file with the -d and -o options; unzip -d -o gen.zip this will give create you a directory structure containing all of the Genesis executable files, plus the programmers toolkit and the documentation needed to start programming. Start windows (if not already) and create an icon using the windows program manager's File/Properties menu item. Both the program directory and the working directory must be set to; \gen\bin or whatever you have called your directory. Copy the Gened.ini file to the main windows directory, eg; copy \gen\bin\gened.ini \windows NOW RUN GENESIS FROM THE PROGRAM MANAGER ICON! Alternatively you could just run it from the Program managers File/Run menu item. The version of Genesis you have is a Freeware copy. Feel free to play with it, develop for it, give it to your friends and write GOOD articles about it in magazines. It will NOT explode after 30 days leaving a nasty mess on your hard disk, however you are limited to a maximum of 1000 polygons. If you would like an unresricted version, this is available from the author for a small fee of 20 quid (which includes posting fee and cost of disks if neccessary). If you are interested in developing tools, Geometry engines or applications, please read the developers note at the bottom of this document. Now follow the user guide... THE USER GUIDE When the editor starts you will see the main editor window and in it a couple of view windows, a tool bar at the top, a status bar at the bottom, and a control bar on the right hand side. At the top of the control bar you will see the 'toolbox'. Each icon in here is actually a button which invokes one of the tools. At this point it is quite likely that you have already been messing around with the program for about 10 minutes and have got yourself confused, or the program confused and have then resorted back to the documentation. (I often do this too). Before I go on let me remind you that Genesis is a version 1 beta, so it is incomplete and yes, it has bugs! You might find that some very basic operations are still not supported, I am not yet too worried about this as generally this is just a matter of writing the tools for the job. At present I am more concerned with getting the API's and supporting framework finished and tested. OK, enough excuses, lets continue with the user documentation; The two views represent two 'scenes'. A bit like two documents in a word processor. One view has a default object in it (just so you can mess around rendering stuff). The other has nothing in it and can be used to experiment with the tools. Click in the view called start.gen to make it active (start.gen is the name of the model file loaded from the \bin directory). Start.gen is a model of an everday goblet with a silvery brick texture on it containing a gold sphere, the sort of thing commonly found in glass cabinets! Actually its really just to show off the surface types. THE VIEW The view is a window into a scene. There can be more than one view per scene. Select the Window/New Window menu item for another view into the active scene. In the view you will see the x, y and z axis drawn, along with a grid in the zx plane. The grid can be changed or switched off from the control panel. The entire overlay can be switched off using the View/No overlay menu item. The grid can also be switched to solid lines or points from the View menu (points take longer to draw). Sort of bug: Changing the size of the view window causes a re-render with a different aspect ratio. This will soon change so you cant easily make your view all squashed up. THE 3D CURSOR If you hold the left mouse button down in the view and move the mouse the mouse cursor disappears and you find that you can move a 3D cursor around in the view. If you move left to right or vice versa then the cursor moves in the most horizontal axis in the view. If its moved up/down then the 3D cursor moves in the most vertical axis. Unless you change the view orientation this will be the x and y axis. To move in z hold down the right button and move up and down. Bug: Sometimes from some views the cursor moves in the opposite direction you expect. All adds to the fun! CHANGING VIEWPOINT To change the direction in which you are looking into the scene position the cursor and press the DIR. button on the control panel. The next time a render is done you will look towards the new position. To render press the cube shaped button on the tool bar below the menu bar (not the toolbox!). Alternatively the File/Render menu item can be used. To change the position you are looking from, position the cursor and press the POS. buttton. The In and Out buttons on the control bar can be used to zoom in and out (all quite intuitive really), and the Back button can be used to step back through all the previous views rendered. So if you screw up and find yourself staring into blank space, just press Back. The Up button changes the up direction in the rendered image. SURFACE DIALOG To edit the surface type of the goblet select the Scene/Surfaces menu item. The dialog shows the properties of the currently defined surfaces. To change the brick texture to a more natural looking concrete, click on the preview picture of the brick surface, then on the filename Browse button and select the conctex.bmp. When the image is rendered it will have the new texure. The preview is a model which is rendered in real-time. You can change the type of the preview model from the dialog. Other options allow you to change wether or not the texture is infinetly tiled, and the type of specular reflections the surface generates. The 'dull' spec reflection actually produces no highlights. Silver produces large bright highlights, Gold produces large dull highlights. Glass gives you very small highlights just around the edges of your object. Linear and Constant are also implemented but the rest just do the same as glass. Notice that selecting these options does not change the colour of your object - just the highlights. To change the colour switch off texturing for this surface and press the colour button. Any windows bitmap file can be used to make a new texture. See the coordinate system editor section on how to specify the orientation of the texture. Bug: I lied, currently only 8 bit (256 col.) and 24 bit bitmaps work! The 'more' button is used to define recursive textures and bump mapping, neither of which the default Geometry engine support, so messing around with these options will have no effect. TOOLS Sphere tool Now go to the blank view. To invoke a tool, say the sphere, click on its button in the toolbox (second one in). The Tool/Configure menu item can now be used to configure the sphere tool. Use this to change to a smooth sphere and OK the dialog. Position the cursor for the center of the sphere and press the 'Set' button on the control panel. Then move the cursor to a point on the radius and press the 'Do' button. The surface is coloured with the currently selected surface type from the surface dialog box (the one you clicked in last). A new object called 'sphere' will appear in the object listbox. If you create a second sphere object it will be called 'sphere2'. This applies to all tools that create objects. The 'Mapped texture' checkbox in the sphere config dialog will be used for warping a texture into a spherical map so that the image doesn't distort across the surface of the sphere. If you think I'm talking cac please ignore the last sentance. All tools that create primitive objects or bits of objects use the currently selected surface type. The grand list currently consists of; Patch, Sphere and Spin tools (the first, second and seventh respectively in the toolbox). Bug: You can change the 'Number of verticies' field in the configuration of the sphere but some values will cause the code to crash. The number is only an approximate indication anyway Patch tool The most basic of all tools, enables you to create a patch or polygon by positioning the cursor and pressing 'Set' for as many verticies as are needed. The patch tool is the first one in the box by the way (if theres one thing I learnt its that doing 3D icons is harder than 2D ones). Use 'Do' to create the patch. All points must lie on a plane but you are not limited to how many points you create. You can define a 1,000 point concave outline and as long as all the points lie on a plane then Genesis will split it up into lots of small patches (of up to 4 verticies each). Each patch has a solid and an empty side. The patch must always be seen from the solid side as it will actually become invisible if seen from the wrong side. You implicitly define which side is solid by ALWAYS drawing the verticies CLOCKWISE as seen from the outside. You must also select which object in your scene you want the patch to belong to. Do this by highlighting the 'start' object name in the rightmost listbox on the control panel. The 'start' object is initially empty. Was that a bit un-intuitive? If it was then you will find yourself very rarely actually using this tool as other more powerfull ones actually build whole objects for you. Spin tool This allows you to define an outline which is spun around an axis to form a cylindrical type formation. The goblet was done using this technique. Select the tool (7th one in toolbox). Position the cursor at a point at the start of the axis you want to spin in and press 'Set'. Then position the cursor at the end of the spin axis and press 'Set' again. You will then be presented with an outline editor. The vertical axis of the editor is the line you have just drawn in 3D. Each press of the mouse button in the editor defines a new segment to be added to the outline. If you want to create a disconnected part of the outline use the 'move' button. If you want to create an arc, circle or box as part of the outline, press 'move' and position the 2D outline cursor at the center of the arc/circle or corner of the box. Then position the cursor at a point on the radius or the other corner and press the appropriate button at the bottom of the editor. When you OK the dialog a wireframe is drawn in the view, if you're happy with it press 'Do', otherwise you can reposition the end of the spin axis and press 'Set' again to get the outline editor back. IMPORTANT NOTE: Consider this. In the outline editor you define a line segment coming out from the bottom of the vetical axis and extending right. Then another segment goes straight up. Now given that patches have a solid and an empty side, have you defined a sort of cylinder (solid on the inside, where the spin axis is) or a sort of cylindrical hole which is solid on the outside (and empty space where the axis is). The answer is you have defined a solid cylinder because the outline is always solid on the left hand side as you draw it. If you 'moved' to the end of the cylinder first and then drew down to the axis origin, then would would have defined a cylindrical hole! When defining arcs and circles a negative arc angle makes the outline proceed clockwise instead of anticlockwise (ie. giving hole type outlines instead of solid ones). The Spin tool has a configuration dialog box which is accessed the same as for the sphere. Diff, Union an Int tools These tools are more complex than the others, (and took longer to write). Having created two objects such as a sphere and a spin object you will notice that their names appear in the right hand list box on the control panel. If these two objects overlap in space then using these tools you can perform a CSG (constructive solid geometry) (sometimes called boolean) operation on the objects. The diff tool (3rd one in) subtracts one object from another. Highlight the names of the two objects in the listbox, select the tool, and press 'Do'. Indicate on the dialog which object is subtracted from which, and thats all! When the operation is complete the all views into the scene are re-rendered. The union tool joins two objects together such that the patches form a continuous mesh across the surface. The intersection tool takes only the overlapping part of the two objects. After the operation only one object will be listed in the object listbox with a name like 'diff object', 'union object' or 'int object'. The configuration dialog boxes for these tools allow you to specify how the smoothing is to be performed if a curved patch from one object joins a curved patch from the other in the resulting object. Enclosed tool I said earlier that all patches have a solid and an empty side, and that if you view it from the wrong side it will become invisible. This is OK because each object should be a continous polygon mesh surface, in other words each edge of each patch should be connected to another patch thereby preventing you seeing the wrong side of any particular patch. Unless of course you intend to view the object from the inside in which case you should design its inside as another continuous polygon mesh belonging to the same object! If an object isn't a continous mesh nothing will go wrong, its just it might look like you have holes in it when seen from certain angles (ie. when looking at the inside of patches). What is more the CSG tools will warn you if either object is not completely enclosed as sometimes the results you get from un-enclosed objects might not be what you expected. So to cut through the waffle, the enclosed tool highlights any unconnected edges in all objects in your scene. When developing tools this can also act as a debugger to check your tool is giving sensible results. To try it out simply create a patch and select the enclosed tool (6th one in toolbox). It has no configuration dialog. Bug: Very occasionally the CSG tools will generate an object with unconnected edges. Coordinate system editor The coordinate system editor (8th tool) is a very powerfull tool. It doesn't work on objects themselves but on the coordinate systems they belong too. So far both of the scenes you have been experimenting with have each had a single coordinate system. The left hand listbox of the control panel contains a list of the coordinate systems belonging to the active scene. OK, let me start by posing some problems, then maybe the significance of coordinate systems will become more obvious; Prob 1. You have designed a large cube with one corner at the origin. You now want add a load of primitives (spheres, blocks etc.) such that they appear to be sitting on one of the faces of the cube. However the face you have chosen is the back vertical face! Even if you re-position the viewpoint so you can see what you are doing you are used to working on a flat horizontal surface not a vertical one and have trouble adjusting. Worst still suppose the face isn't exactly aligned with one of the axis, you will have terrible trouble knowing wether your new primitives are actually sitting on the surface, penetrating it, or sitting too high above it. also some primitive creation tools might only create primitives algined with the axis. Prob 2. When defining a texture, the bitmap you use is placed in the xy plane of the coordinate system. If your bitmap is 100 pixels wide by 80 high then the extent of the texture will be from the origin to x=100 and y=80 (if not tiled) and will be projected through the z. Suppose you want the texture scaled to x=1000 to y=800 or projected down through the zx plane. Prob 3. You are using an animation tool. You have a landscape and within it a river. On the river is two boats; A and B. Boat A has 10 people on it. When the boat moves relative to the landscape all the people on the boat must also move (otherwise they will end up suspended above the river!), BUT the people must still be able to move about on the boat. Boat B obviously moves indepentently of boat A. You need a way of telling the editor that the people objects of Boat A must move when the Boat A object moves and likewise for Boat B. The answer to all these problems is coordinate systems. The coordinate system editor tool enables you to define a new coordinate system relative to the currently active one (which is called 'top level' unless you've already created some). The new coordinate becomes a 'child' of the active one and the three buttons at the bottom of the coor sys editor dialog allow you to reposition and scale it relative to its parent. When you create a new coordinate system (using the 'New' button) a new view is automatically created for you. To modify a coordinate system relative to its parent, first make it active (by clicking in its view, or selecting its name from the coor sys listbox). Then click the 'Modify' button. The tool then makes its parent's view active and draws a represention of its axis's within its parent. Then using the Origin->Cursor button you can move the origin, and using the Z Axis->Cursor button you can specify a direction towards which the z axis should point. The third button; Y Dir->Cursor can be used give an aproximate direction to the Y axis given the constraints of the origin and the z axis. The new view can be used exactly like its parents view but what you have really done is turned the world on its head so that you can work with a sensible set of axis, while the rest of the world (ie. everything defined in the parent coor sys) is at an awkward angle. You can define a coordinate system purely for the purpose of defining a texture position. The surface type dialog has a combo-box field where you can tell it the name of the coor sys the texture is defined in. You can then close down the view if your not going to be working in it (this doesn't delete the coor sys). In the Prob 3 example boats A and B will each have their own coordinate system which is a child of 'top level'. The landscape will be defined in 'top level' by a bunch of patches. The individual people of boat A will each have their own coordinate system (as they can all move independently of each other) but they will all be children of the boat A coordinate system (as they must move if the boat moves). Boat B will likewise have its own coordinate system as a child of 'top level'. Normal tool The normal tool (last one in the box) draws onto the view the normal (or arrow perpendicular to the surface) of each every curved patch facing the view. Since the tools described create the normals for you, you will rarely need to use this, however eventually this tool will enable you to 'grab' a normal with the mouse and bend it, thereby changing the shading at that point on the surface. Even then this tool is really just for perfectionists who maybe dont like default smoothing effect of some tools. The normal tool will be good for doing things like, putting a dent in the side of your object, eg. a dented, brick coloured goblet, with a dented gold globe in it! Obviously there is no limit to your creative potential. ...Watch out for more tools ROYALTIES ON API USEAGE I must apologies to those whom I told the API was free to use in your own programs. Dont worry just yet - please hear me out. I was strongly advised for copyright reasons to demand a small royalty fee on use of the API. I want to keep this as low as possible as I want to encourage people to use the API. If you want to use the API in an application or tool that will be sold for profit, then a small royalty fee of 2% of the retail value of the product will be charged on each unit sold. 1% if any part of the maths, debug or Helper API's are used without the Geometry API. This note applies to use of the API's irrespective of wether the libraries themselves are used. DEVELOPERS NOTE I think this is the bit a lot of people have been waiting for. This is the agreement; This version of Genesis is Freeware. Soon there will be a commercial release. The more tools and/or Geometry engine's it supports the better, so if you are interested in developing for it, send me what you have and if its of general use to others (ie. no spinal column fracture detectors please) it will be included. This is your chance to get your name in lights and obviously a royalty payment in your pocket. The initial release will be under £100 (pounds) unless there is such a wealth of tools that puts us way above the competition. This would be nice but I'm trying to be realistic. I will have to work out fairly on an individual basis the royalty payment based on effort put in and value it adds to the package as a whole. From the overwhelming response I had to my original append I'm sure this is going to take off in a big way. I will endevour to set up a Genesis newsgroup so that developers can talk to each other and help each other with their problems. This will also serve to ensure that developers aren't writing the same tools (.DXF loader anyone?). I am of course still working on Genesis and have my own schedule, however if there are areas you would like completed sooner rather than later in order to develop tools then feel free to E-mail me a request. Once again, Genesis (particularly the editor and the tool interface) is not complete by a long way. I am confident that by the time we reach first release which hopefully will be well within a year, it will be one of if not the most powerfull PC based 3D graphics development tools available.