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kbenderoth89

Member Since 28 May 2012
Offline Last Active Jun 12 2012 05:10 PM

Topics I've Started

color stripes based on time

03 June 2012 - 12:17 PM

In a class I am taking, we had to create an object, make it rotate and scale (done) and have rainbow stripes moving upwards towards the Y direction as it is scaling and rotating. I was unable to get the last part done. Still passed though :), but I don't believe in "good enough" so even though it's aready graded, I want to finish it and make sure that I am able to do it again if I ever need to.

So I'm using FX Composer, and I set up the pixer shader to return the world location, which I know changes the color based on the location. But what I WANT to happen is create a stripe pattern full of colors of the rainbow, and they'll be moving upwards as time goes by. All I know is that it'll involve sine, cosine, and tangent. But I have absolutely no clue how that would work or why. I haven't done trig or calc related stuff in years so if someone could also explain how manipulating the sin,cos,and tan waves works also that would be awesome.

3D scaling using sine based on time

03 June 2012 - 02:39 AM

So I'm trying to make my teapot scale properly when testing my HLSL shader effect.

currently I have this:


float4x4 scale = {(sin(gTime)*sin(gTime)),0,0,0,
0,sin(gTime)*sin(gTime),0,0,
0,0,sin(gTime)*sin(gTime),0,
0,0,0,1};
where gTime is the time elapsed since the program started.
Basically what I want it to do is scale from about 0.5 of its original state to 1.0 (the original size) constantly.
you could probably guess that what I currently have scales it from 1.0 to 0.0
is also tried using the absolute value and, well, it partially works, only the full scaling takes about 4 seconds and it takes 3 seconds before it moves
can anyone help me scale it smoothly from half its size to its full size using sin, cos, or tan?

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