View Full Version : Glow Intensity, Set Driven Key? Help

02 February 2005, 10:01 PM
I am building a spaceship as part of a school project. I have built "thrusters" on the top, bottom, and sides of the ship. When the ship moves in the +y direction, I want the bottom thruster to glow more intensley, and when it moves in the -y direction for the top thruster to glow intensley, and the bottom one to not.

I have attempted makign these Set Driven keys, but it doesnt seem to have the results I want. Its quite hard to explain why it doesn't work right, but i'll try.
I set the driven keys so that at 0,0,0 none of the thrusters are glowing. And at 0,5,0 the bottom one is glowing (and similar settings for all other thrusters). Since the space ship is going to be moving, it may be at point 5, 15, 5, and if want ti to move towards 0,0,0 the thrusters don't act correctly. Sure the thrusters against the ships movement die down, but it isn't untill it passes 0,0,0 that the thrusters supporting its direction light up.

Is their anyway to make it so that when the ship is moving in a direction (say +y) that a thruster glows more intensley REGARDLESS of its position in 3 dimensional space. And when it stops moving in the direction the Thruster stops glowing?

02 February 2005, 03:15 PM
Driven keys only work off of absolute values -- meaning the value at 0 is one thing, the value at 10 is another, what's in-between 0 and 10 is interpolated, and that's it. It doesn't matter if you're moving "up" or "down," if you're beyond the range of the driven key nothing will happen.

If you want the glow to happen relative to your current position in 3D, you'll need to either

1) use an expression to compare the current frame position to the last frame, though sampling values at different points in time can get ugly in expressions...

2) try out dynamics, since particles can do fancy stuff like drive color and opacity based on velocity... or:

3) Just keyframe the damn thing, it'll be easier!

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