Ray Dream Studio Version 5

In late July 1997 MetaCreations began shipping Ray Dream Studio Version 5.0

This major release included a number of improvements and new features. Below are article discussing these new features and/or improvements.

• David Ramirez - Physical Forces

Physical Forces in RDS 5.0

(Because of the intense interest in the new features of RDS 5.0 the following article has been "published" before it was completely finished. Please send any comments or suggestion to the address below - Editor)

With RDS version 5.0 it is now possible to make object interact in a similar way to "real" objects following basic laws of physics.

When an "object" is first created you set it's initial position in the scene and then apply one or more behaviors that allow the object to mimic true "physical forces":

The possible "physical force" behaviors are:

• Initial Velocity
• Directional Force
• Rotational Force
• Apply Physical Effects
• Point Force
• Flow Force
• Damping Force

This example, I call 4-Balls, displays the effects of using the first four behaviors; Initial Velocity, Directional Force, Rotational Force, and Apply Physical Effects.

In this scene there are seven objects that have been given a "physical" existance:

• An Infinite Plane, a new object type in RDS 5. (The yellow lines do not extend into infinity because of a black fog effect used to encompass the scene).
  • It has been given no Initial Velocity, no Directional Force, no Rotational Force, and through the use of Apply Physical Effects it is immobile (it will not rebound when struck by another object).
• Two Cubes.
  • like the Infinite Place these objects are immobile. They are designed to provide something for the Spheres to bounce against.
• Four Spheres.
  • all four Spheres have been given identical Directional Forces to simulate the pull of gravity in the -Y (negative Y axis) direction.
  • three of these four spheres have very similar initial positions and have been given a similar, but not identical, Initial Velocity, Rotational Force, and Physical Effects characteristics (rebound, rotational rebound, and friction).
  • the fourth Sphere has a radically different Initial Velocity that results in the Sphere heading upwards very quickly. The constant Direction Force (simulating gravity) brings the Sphere back to the Infinite Plane.
• The scene also includes a number of cameras and lights. But because no "physical force" behaviors have been applied to these objects they have no influence on the motion of the "physical" objects. Think of them as ghosts perhaps?

Here the motion path for Sphere #1 has been turned on, from the Properties -> General window and RDS displays the path the object will follow through the animation. Here you can see Sphere #1 interacting with the two Cubes.

Warning: From my experience turning on "motion paths" for multiple objects, while using physical effects, seriously degrades the speed of screen refresh and interaction. Until MetaCreations can correct this I would recommend you turn on motion path display on object carefully.

The Final Results:

System Requirements:
To view these animations you will need a browser that supports Quicktime (.mov) video files. Netscape 3.0 and 4.0 with components includes Quicktime automatically. Microsoft Internet Explorer 4.0 also includes Quicktime. If you installed only the minimal browser components you can get the Quicktime plug-in, for Windows and Mac, at the Quicktime Web Site.

4-Balls Animation

This final animation of 4 falling spheres is available in two versions:

• Small Version - Quicktime, 160x120, 16 seconds, 12fps, 16bit color (286K), moderate quality
  • gives a fair idea of how the objects interact and the action of "rebound". Provides a moderately smooth presentation if your time or bandwidth.
• Full Version - Quicktime, 320 x 240, 30 seconds, 24fps, 24bit color (1.8Mb), high quality
  • this clearly shows both the "rebound" of objects and the complex "rotational rebound" that the spheres display. At 24fps it is a very smooth presentation. If you have the bandwidth and/or time I recommend you take a look at this version.

Roller Coaster (Ball's Eye View)

This is the same scene as 4-Balls but I linked and locked a camera to Sphere #1. I found this "Roller Coaster" ride rather amusing.

• Only Version - Quicktime, 160x120, 14 seconds, 12fps, 16bit color (289K), moderate quality

Hand Drawn Animation

This is the first 12 seconds of the 4-Balls animation processed through one of the included Thinkfish filters (see the Thinkfish website for more details).

• Only Version - Quicktime, 320x240, 12 seconds, 6fps, 256 greys, cinepak, (293K)

All animations were done using RDS's 5 "raytracing" rendering (unless otherwise noted). All options but "shadows" were turned off. They were performed on a PowerMac 7500 running a 233Mhz 604e CPU with 64Mb of RAM dedicated to RDS.

If you wish to see the details of the scene please download the RDS v5 scene file:

4balls.rds - Ray Dream Studio v5.0 scene file. (23K)

I would love to hear any questions or comments you might have regarding this article or your experience with RDS v5. I can be reached at dram@best.com.

Submitted 8/5/97
Updated 11/21/97