Spreading of a dynamic texture (color)

Hi guys, thanks to joreg i managed to solve my previous problem on spreading of a halo ring animation here: https://discourse.vvvv.org/t/7287 but now i have some more probs on spreading another dynamic texture…

it’s easier than my previous patch but now i am using a dynamic texture (color) and not (value) - by the way i have tried with a dynamic texture (value) too and does not work either.

again…thanks everyone!

dynamic texture spread.v4p (10.1 kB)

hard to guess what it’s supposed to look like, but, you did a couple of strange things there…

  • you spreaded the alpha channel and put the texture on a sphere. that will most likely lead to artefacts
  • the topmost linearspread was parameterized in a way that won’t fit an alpha channel well
  • the next linearspread was spreaded to a random number not fitting the upper spread
  • on the dynamictexture you spreaded both width and height, resulting in 256x256 pixels per texture but only fed the node with 512 values.

all those together likely make the output unpredictable. i cleaned up the patch a bit, see attached.

dynamic texture spreaded.v4p (10.3 kB)

thanks joreg for helping me again, the main mistake that leaded me to write a post was that i spreaded both width and height of the dynamic texture…i agree with you: difficult to imagine what i wanted to achieve, i dunno either it was just testing out ;)

by the way i cannot understand the first 2 statements you say about the alpha channel…if you pass by and have some time i’d be happy if you say something more about it…

thanks again

ao,

ad 1)
transparent textures on double-sided meshes (like a sphere) are problematic since rendering with transparency requires such polygons to be drawn last always which is not automatically handled by a mesh and thus results in artefacts easily. simple workaraound: draw mesh twice with opposing cull modes, ie. first the backfacing polygons, then the frontfacing. i think that does in most cases.

ad 2)
alpha-channels are parametrized from 0 to 1 and you set it some values from -something to >1 which while not causing any harm (since values are clamped there anyway) just doesn’t help in understanding what the result would look like.

hope that helps.

thanks that surely has helped, didn’t know the cull node!