Main Site Links Resources Tutorials
News VB Gaming Code Downloads DirectX 7
Contact Webmaster VB Programming Product Reviews DirectX 8
  General Multimedia Articles DirectX 9
      Miscellaneous

Geometry manipulation
The ability to manipulate the geometry you can create in Max 5 is one of it's strongest points, and one of the reasons why it has legions of loyal supporters in the real-time 3D graphics industry. Max 5 has all the standard tools and more - given the strong library of basic geometry objects (cube, sphere, cylinder etc...) there is almost nothing that you can't create using them. The real star, for me at least, is their ease of use - most other 3D modelers will offer similar tools, or at least a way to achieve the same effect, but very few are as easy and intuitive to use.

For real-time low-polygon modeling, it is essential to have control over every face, edge and vertex - and be able to use the tools on these geometry building blocks. One example where this is the case is with box-modeling, a method typically used to make low-poly objects: vehicles, buildings, characters etc...


the basic cube mesh to start with


Vertex-level editing to create a tail-fin


Extrude and Chamfer to create an exhaust


The final low-poly mesh: 120 vertices / 236 faces.


A smoothed version: 671 vertices / 966 faces


The final mesh rendered. All it needs is some texturing and
it would be ready to go...

The above example, box modeling to make a space ship took only a matter of minutes (around 17 to be precise). The above model is hardly ground-breaking, and would probably be laughed at by an experienced modeler (I'm a programmer most of the time! not an artist!) you can obviously see the potential it has - a slightly more thought out mesh and a good use of textures/materials would make this a perfectly reasonable model for use in a game environment (966 faces is a reasonable number).

The key to Max's success in the past and in this version is it's extremely easy to use and very powerful 'Modifier Stack'. It is this method of geometry creation and editing that makes 3ds max 5 so intuitive and powerful. The modifier stack is literally what it's name implies - a stack of modifiers. Typically you'll start with a standard geometry type, then apply an "edit mesh" modifier so you can refine it's shape, then maybe add a mesh-smooth modifier like that shown above. You can then use mesh select, UVW maps and UVW unwraps to texture each face (or selection of faces) as you see fit.

The image to the left is an example of the modifier stack involved in texturing a simple cube (bare in mind this isn't necessarily the best way of texturing a cube). The list works from the bottom-up, such that I started with a simple box object, applied an Edit Mesh modifier (so I could access each face/edge/vertex), then went around all 6 faces selecting and texturing them.

Because of the stack nature, if you edit a modifier lower down the list you'll probably alter the modifier(s) that follow it. Max will usually warn you when this is the case, but it is a useful feature nonetheless. As a trivial example, in the image to the left I've got a textured cube. It may well prove easier to texture it when it's viewed as a cube, but then when I go back to the Edit Mesh modifier I can stretch and distort the cube to make a completely different shape - yet the textures will still stay the same (as long as I don't add/remove geometry).

Other new features in the Max 5 geometry manipulation toolbox include symmetry modifier - similar to the mirror tool in trueSpace 6; whereby you edit on side of an object and the program will mirror it to the other side - very useful when you want to create symmetrical meshes (vehicles, heads etc..).

The majority of new features of interest here don't actually affect the end-mesh, rather they aid in creating it faster and easier. Max 5 packs in several new forms of mesh-selection tool: shrink/grow current selection, named selection sets (similar to, and works well with layers) and soft selection to name but a few. Each one alone is only a small addition, but combined (and once you're used to them) they will shave time off the often tedious process of selecting many faces on a mesh.

Animation
3ds max has always been a good static-modeling program (as covered in the last section), but it has also been a great animation package. Static models are always going to be useful (and necessary), but complex animation is only just starting to become as important in the real-time graphics industries.

Like with all similar applications Max 5 uses a method of animation key-frames and interpolation between them. This system can be as simple or as complicated as you choose. At the simplest level you can create your model, position it (and key frame it), then move it and key-frame it again. Or you can do the same and go to the graph editor and alter the way in which interpolation occurs between the two key-frames (by default it's usually linear).

 
click to enlarge

In the above screenshot we can see the curve-editor, Max 5's tool for altering the default interpolation method. Many animation packages have a similar tool, but Max's is the easiest to use (from the ones I've sampled). The left-hand image is a default curve set up by Max when I applied a bend modifier to a cylinder, and animated the bend over 100 frames. The right-hand image is after I changed the in/out at each keyframe - creating the appearance of a 'spring' in the animation around the middle keyframe. Modifications were made simply by selecting a keyframe and dragging it's handles (you can see them in the screenshot). It is possible, as you can see in the treeview, to alter the graph for any properties of the original geometry and it's relevant modifiers - making for a very powerful, yet still very intuitive tool.

As powerful as these tools get, trivial animation (as covered above) is only 1/2 of the package - the true power, and of most use to real-time artists is going to be skeletal animation. This uses a complex system of bones and physics (Inverse Kinematics), and is where Max 5 yet again has a chance to shine.

Bones are relatively easy to configure using Max 5 - but mastering them is very difficult, not because Max 5 makes it this way - rather that the very nature of bone modeling at this level requires a certain level of expertise. Compared with the rest of Max 5, this is the most complicated set of tools to use - you really do need to know what you're doing, or at least roughly what you need/want. Animation and Bone modeling is one area of this program (and similar programs) that I've not got a lot of experience in - from a beginners point of view it was interesting how far I could get just by guessing which tools to use, and reading a few tutorials. But at the end of the day, it would take much more experience and much more skill than I currently posses to create professional animations that I could use in a game!

Luckily for anyone unfamiliar with this advanced animation there are a couple of good tutorials (including sample files) included in the manual and training CD. Having worked my way through these I have considerably advanced my animating skills, but they could still be improved further...

There are two very useful tools for real-time modelers in the Max 5 arsenal: weight editing and character studio 3.4. 

As demonstrated in my Direct3D8 tutorial on vertex skinning (found here), it makes for much better animation to use matrix-skinning effects - which are primarily determined by weights set for each vertex used. When dealing with bone animation in Max 5 it is a breeze to configure these weights, and have them exported out for use in Direct3D (as one example). There are two routes you can use - editing "envelopes" or directly altering the weight table. Envelopes are literally 3D volumes around each bone indicating how much vertices (in the envelope) are affected by movements of that bone, if you overlap different envelopes, you instantly get more organic and lifelike animation. The weight table is more complicated - envelopes allow for a clear visual representation, but this is just a spreadsheet of numbers: only really useful if you need any special changes/corrections.


Editing Skin Envelopes: Red=higher influence, Blue=no influence


The weight table: for revising and customizing the effect
created in the envelope system.

Character Studio is a long-running plugin for 3ds max, due to have it's 4th major release this autumn. To put it simply, it allows an artist to make a biped (human) skeletal animation very quickly - you can just select a biped object to create, drag a box and voila! you have yourself a human skeleton:


A basic character skeleton

Character studio still requires the artist to make the skin for the character, but at least one of the more complicated aspects is greatly simplified. 

Inverse Kinematics - the physics system used to manipulate bones has also had a few new additions implemented. Nothing hugely revolutionary, more a case of useful tools improved or added. The interface for handling bones has been updated slightly - making it easier to get to the important tools faster. A Spline IK solved has been added - which will really help with organic modeling of tails and snakes (for example). Fin-editing tools have also been improved.

Previous Page <<  >> Next Page


Review Contents:
Page 1: Introduction, The Full Package, The User Interface
Page 2: Geometry Manipulation, Animation
Page 3: Textures/Materials, Rendering, Supporting Tools, real-time multimedia, Conclusion

DirectX 4 VB 2000 Jack Hoxley. All rights reserved.
Reproduction of this site and it's contents, in whole or in part, is prohibited,
except where explicitly stated otherwise.
Design by Mateo
Contact Webmaster