4D Noise

Started by Hannes, November 09, 2015, 09:29:13 am

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Hannes

I'm sure I read something about that some time ago, but couldn't find it: what does "Reference frame number" do in the 4D noise tab?

Tangled-Universe

This is the only bit of info I could find and it was posted on the alpha forums.

Quote
It's difficult to anticipate the effects of animating the speed parameter, because the position in 4d noise space is calculated from the current time, the reference frame number, and the speed. Changing the speed doesn't just change the rate of change from one frame to the next, it changes all frames, because every frame is calculated based on the time difference from the current frame to the "reference frame number" and that difference is multiplied by the speed.

I thought I was making things easier to use by providing a speed control so that you wouldn't need to keyframe anything to get simple animation, but it's making it difficult to animate the speed.

Hannes

Thanks, Martin!

Hmmm, I don't think, I am smarter now... ???

Hannes

However, there's a reason, why I asked this question: Say you have a cloud formation, you really like and afterwards you decide to animate this. Once you enable 4D noise everything looks completely different. I thought maybe this reference number would mean that the evolution starts from this frame. But obviously it doesn't.

Kadri


I had the same problem and Just because of that i did not use the 4D noise option(the appearance changed too much).

Just speculation on my side but if you enable it and see somewhere in a frame something you like and use that frame as reference that the animation will be more like that frame???
Obviously i don't know too what it means.

Hannes

Quote from: Kadri on November 10, 2015, 09:58:59 am
Just speculation on my side but if you enable it and see somewhere in a frame something you like and use that frame as reference that the animation will be more like that frame???


Thanks Kadri. Unfortunately not as far as I can see. But maybe there's something we missed?!

Kadri

Quote from: Hannes on November 10, 2015, 10:03:17 am
Thanks Kadri. Unfortunately not as far as I can see. But maybe there's something we missed?!


I think so too :)

Tangled-Universe

My quote of Matt is explaining it, but it's perhaps a bit mind-bending.

I just imagine it as like the 4D noise needs a "reference frame" (starting frame, if you like) together with current render frame to calculate the 3D noise result.
So the noise pattern is a result from a calculation in the 4th dimension, time, which is based on the reference frame and the current frame.

Hetzen

You're adding another 8 corners to test against by adding a 4th dimension. 2d has 4 corners to make a square, 3d has 8 to make a cube, 4d has 16 to make a tesseract. So it's not surprising that a general shape will alter by adding an extra dimension.

The nice thing about 4d, is that one dimension is hidden to our 3d, which means it has no perceived 3d direction when it's modulated.

TheBadger

[attachimg=1]



;D

:-\
It has been eaten.

Hetzen

Great animation Badger, it sort of explains what happens when you add an extra dimension to a cube, but it's not what a tesseract really looks like. Tesseracts are mathematical constructions and are really hard to visualise.

This I think is a better way of explaining how you give a cube an extra dimension.


The grey lines are the fourth dimension.

The way most noise works is by finding the distance a point is within a world grid structure to each corner of that grid, each corner having it's own random offset. Adding them all up and dividing by the number of corners gives a value for the point being tested.

;)

TheBadger

*Head explodes emoji here*

It has been eaten.

Hetzen

Ha ha.  :D

String theory has a minimum of 10 to 11 dimensions to contend with whilst trying to explain matter at the quantum level. The way I understand people working in that field visualise it, is by taking slices of dimensions at a time.

So in the case of 4d noise in TG, time is used to give us a slice of 3d noise per frame.

TheBadger

November 11, 2015, 05:28:05 pm #13 Last Edit: November 11, 2015, 05:42:06 pm by TheBadger
When you guys open the gate, and Steven King's "The Mist" happens, you will feel very bad about things.


Hmmmm,

I think the gif above is the center of the Multiverse, and the reflections show the infinite possibilities. At the center, all the possibilities collide.When the power grid goes down and the gif is stopped, all reality will stop.


No, sorry, not "the multiverse", I should say all space and time. Where the center is how space and time coexist in the eternal now... Or something. And the reflections are every time and place in the universe expanding out from the center of a perfect sphere in every direction forever... But in cube form. And we are down the path of the ever reflection, but also here and now, now , now , now , now , now...

Who needs LSD when you got TG?
It has been eaten.

AP

As long as there are no Red Lectroids involved.