CompuServe Messages

#3D modeling

    07-Nov-94 17:12:55
Sb: #455-#3D modeling
Fm: Dwayne L. Liddell 74644,2416
To: Jim 73251,3315
Continued from previous message- 2 of 3 Lightwave has the ability to create primitives, as well as 2D shapes. Like 3DS you can extrude and lathe these shapes, but with less versatility. Lightwave also has the ability to model with spline patches. However, using Lightwave's spline patches isn't easy, or versatile. In fact, it is almost as useless as 3DS's bevel. Actually, some would disagree. Seaquest was supposedly modeled with Lightwave's spline patches. Modeler's real strength is in its ability to manipulate points and polygons. This is accomplished two ways, by simply dragging them around, or using some of the many powerful tools intended for this. These tools include shear, twist, multiple forms of taper, magnet, vortex, multiple forms of pole, beveling that works, patch, skin, morph, multiple types of cloning, jitter, boolean, etc. These are useful and very easy to use. With magnet, you can select an area of an object and tug on it just like a real magnet. Jitter randomizes points within an object. This is very usefull for making rock forms such as astroids and cliffs. Modeler also has excellent drilling tools. These are used to punch holes in objects, using either 2D or 3D objects as templates. What seperates these from boolean is that they don't need to intersect the object being drilled. It is great for doing things like making holes in walls where doors will go. But by far the best feature of modeler is metaform. Metaform is a type of subdividing. Primitives are used to create smoothly curved objects. This is useful for making very complex organic objects. I modeled a very complex chandalier in just a few hours. Metaform isn't particularly accurate and sometimes the polygon count gets way out of hand, but those are my only complaints. Modeler also has a powerful macro implementation. Using Arexx, you can program macros do do almost anything ranging from centering an object to creating router bits for beveling. Macros aren't as versatile as IPAS modules, but you can easily create them yourself. Newtek includes a ton of them with the program. Modeler is rough around the edges in some spots. It is difficult to accurately model some types of complex non-organic objects. There are also more things to worry about (like non planar polygons, polygon alignment, stray points, etc.) than 3DS. A winner can't really be declared in modeling. Each one has its strengths and weaknesses. I often model the basic shape of an object in 3DS and import it into Lightwave for refinement. Since Autodesk pulled spline patch modeling out of R4, Lightwave 4.0 will likely take the lead in modeling. Both programs have similar animation systems. 3DS uses the Keyframer for all animation. Motion can be created using either keyframing or importing a spline path from the Shaper. A slider along the bottom of the screen is used to cycle through the frames. There are also VCR-type controls on the bottom right. Creating a keyframe is as simple as moving the the frame you want and moving, or rotating the object to the desired position. There is no need to set the keyframe. This is sometimes a problem because if you move something and want to move it back you have to go into the tracks submenu and delete the keyframe. This can be annoying. 3DS has excellent hierarchy creation tools. You can assign objects to copy every motion of their parent, or just certain types (ie rotation, position, scale, or squash). The tracks submenu is another excellent feature. It allows you to easily move, copy, or delete keyframes. The keys submenu allows you to change the continuity, bias, tension, ease in, and ease out, for each keyframe. Each type of motion (ie. position) can be independantly adjusted. However, the graphic representation of motion shows only the current frame, and it is not very easy to understand just what it is doing. Ipas modules are available to do special types of animation (such as particle animation, manta wave, and melt). 3DS also provides the standard morphing features. Cameras (3DS can use multiple cameras, Lightwave can only use one) are controlled by moving the actual camera and the camera's target. to move the camera you select the actual camera and move it, to rotate where it is viewing, you move the target. There are no provisions for changing the heading and pitch using degrees. Spotlights function the same way. Lightwave is similar to 3DS in motion creation. Lightwave also uses keyframing and spline paths. A timeline is moved to the desired frame, the object is positioned and then the keyframe is set. By manually setting the keyframe you avoid having to take the time to delete the frame if you don't like it, but it is easy to forget that to set it, change the current frame, and lose your keyframe setting. Lightwave has similar hierarchy controls as 3DS, but lacks the ability to lock only certain types of movement. The scene menu and motion control graph offer similar features as the tracks submenu in 3DS. In the motion graph tension, bias, and continuity can be changed. Lightwave has no ease-in or ease-out features, but because of how tension is set, they are not necessary. The advantage Lightwave has in this area is that all keyframes are shown at once. They are linked by visual splines. This is a superior method to 3DS's keys submenu because it lets you see the whole picture. Lightwave has similar morphing features to 3DS. Cameras and lights are rotated using heading, pitch, and bank. This generally provides greater accuracy. You can also assign targets which function identically to 3DS's. Lightwave has two very unique animation capabilities. One is bones. Bones are used to organically deform objects. They are set as children to the parent object. The most obvious use is in character animation(ie a walking cow). They are sometimes unpredictable, but if used right are very powerful. The other feature is displacement mapping. Displacement mapping moves polygons within an object similarly to texture mapping. In my opinion this is one of the best features available on a desktop 3D program. It can be used for a large number of applications, such as creating water that laps up and down on the side of a boat, a realistic waving flag, grass blowing in a breeze, embossed images, procedural craters on an asteroid, or even blowing apart a brick wall. The quality of the displacement mapped objects is stunning. The procedurallly created water is truly photorealistic. All of these are impossible with 3DS. Also many more things can be animated in Lightwave than 3DS. These include fog, dithering, saturation, and textures. Third party animation enhancements are also available. Advantage……………….Lightwave. Even though 3DS has slighty more versatility with hierarchies and motion smoothing, I still find it easier to create the motion I want in Lightwave. It has a very unique "feel" to it that is unexplainable. Plus with all of the other features it gives Lightwave the definite advantage. Even with the stack of IPAS modules that I have, I still like Lightwaves animation capabilities more. Lighting is where some of the greatest differences between the two programs exist. 3DS has two types of lights; spot and omni. Omni lights shine in all directions. They can assigned a color, strength, and fall off. Spot lights are more versatile. Spotlights can cast shadows. They can be either circular or rectangular. The biggest advantage 3DS's spotlights have is that they can project an image. This is very useful for faking effects such as light shining through a stain glass window, or faking shadows. They render very fast and do a good job. Both types of lights can exclude specified objects. Lightwave has three types of lights; distant, point, and spotlight. All three types can cast shadows. Point lights are very similar to 3DS's omni lights. Distant lights act as a light infinitely far from the scene. They are primarily used to simulate the sun's light (this is impossible to do accurately in 3DS). Lightwave's spotlights are similar to 3DS's except they cannot exclude specified objects, project an image, or cast a rectangular light. 3DS wins the lighting catagory. The versatility they offer is much greater than Lightwaves lights. The image projection is a fantastic feature. It can be duplicated by Lightwave, but it is difficult and time consuming. Texture mapping is considerably different between the two programs. 3DS creates the textures in the Material Editor, and applies them in the Editor. It has the standard parameters for creating the textures(ie transparency, diffusion, specularity, bump…). It also has some unique parameters such as blur reflection. Reflections can be created without raytracing which speeds up rendering considerably. However, their quality is considerably worse than ray traced reflections. All parameters can be controlled with alpha channel maps. Textures can be applied using planar, cylindrical, spherical, and cubic methods. They are assigned within the Editor. The method it uses to assign textures is tedious, especially on complex objects. Mapping coordinates can be applied to objects created in the Lofter. Smoothing groups are also clumsy. The Materials Editor is much nicer looking then Lightwave's surface menu. It renders samples of the texture at the top of the screen. This is a big plus. Procedural textures are available via IPAS, but IMO most are not very good.