Tests & wishes


#1

Hi there,
within the last month, I found some spare time to dig deeper into Krakatoa, while I still feel I’m just scratching the surface.
Partitioning, repopulation, mblur and dof are quite easy to understand and give stunning results in no time.
However, I would love to see more examples regarding especially the channel ops.
Still struggle a bit with some of these buggers- while tutorials & trainings are rare and the documentation is brief.

These are some tests from earlier this year:

TFD XP Krakatoa R&D 1
vimeo.com/116582978

XP Krakatoa R&D 2
vimeo.com/117070605

XP Krakatoa R&D 3
vimeo.com/119662464

XP Krakatoa R&D 4
vimeo.com/119712709

Cheers,
C.-


#2

I agree the docs could be better.
I guess we could help each-other. Your knowledge of CINEMA 4D is surely deeper than mine, and the other way round when it comes to Krakatoa.
So if you could post examples where you feel Channel Ops would be required, but you are struggling to figure them out, we could try to look at them case by case and also generate content for others to follow.

Can you describe a case where you tried to use a Channel Op but failed?


#3

Yeah, of course-
Not sure if this is a failed operation, but anyway, I could need some help:

I have a non-cached X-particles simualtion (driven by a TurbulenceFD velocity field),
and used the Krakatoa X-Particles Source Object.

That Source Object has a Channel Gradient tag.
Source Channel Name: Velocity (listed as available)
Destination Channel Name: Color
Gradient Input From: Magnitude (Normalize Gradient Input checkbox is enbaled)

Looks like this:
vimeo.com/123557034

So the velocity gets correctly mapped, but:
The problem I have, is that it’s flickering, randomly changing all colors or pumping.
Why is this happening?

Cheers,
C.-


#4

Basically the Normalize Gradient Input option means that Krakatoa will collect the Minimum and Maximum values ON THE CURRENT FRAME and map the left-most color of the gradient to the minimum input value, and the right-most color to the maximum value. If on the next frame the min. or max. is different, the Gradient will shift, resulting in the pulse you mentioned. Basically we take the incoming range of the data and remap it to 0.0 - 1.0 range (that’s what “Normalization” means).

If you disable the Normalize Gradient Input option, a Velocity Magnitude of 0.0 (no motion) will map to the left-most color, and a Velocity Magnitude of 1.0 will map to the right-most color. Any values that are below the min. will map to the left color, and values above the max. will map to the right value.
You can then use the Scale Gradient Input and Offset Gradient Input to shift the range - for example, if Scale Gradient Input is set to 0.01, the Velocity Magnitude of 0.0 will still map to the left-most color, but the right color will be mapped to a Velocity Magnitude of 100 (because 100*0.01 = 1.0). If you want to shift the Gradient so 0.0 does not match the left-most color, you can use the Offset value…

Hope this helps!


#5

As always, it does!
Thanks again, Bobo.