rise

[lycium]

http://lyc.deviantart.com/art/rise-64751071

a cropped+resized preview (see link above for the full 1920x1200 image):

[Nahee_Enterprises]

Very Nice!!  I like your Sierpinski Sponge very much.   

I understand the blurring used for the area furthest away from the viewing point, but I question the blurring used for the area closest to the viewer (unless, of course, you were trying to simulate a camera lens that has focal point towards the center of the object).

Anyway, great work!!

[lycium]

thanks

I understand the blurring used for the area furthest away from the viewing point, but I question the blurring used for the area closest to the viewer (unless, of course, you were trying to simulate a camera lens that has focal point towards the center of the object).

i'm doing exactly that btw, since this appeared in my deviation "23", it's been used for all the new 3d apophysis fractals... coincidence? you be the judge: http://comments.deviantart.com/1/62663760/521757431

besides the light bouncing around inside the fractal (potentially infinitely!) there's a thin-lens camera model, so i set the focal depth, aperture size, field of view, ... just like a normal camera. since this is a spectral renderer i could eventually integrate "real" cameras, via measurements like these: http://www.graphics.cornell.edu/online/measurements/sensors/index.html i did a fun little test with the depth of field later (http://lyc.deviantart.com/art/allura-text-64901142) and it's also used in my "snow" deviation (http://lyc.deviantart.com/art/snow-64216165).

[David Makin]

Excellent work Thomas !

I'm lazy sometimes - is there any chance you could let me know the correct coords. of the vertices ?
(I'd like to try this using my 3D escape-time IFS formula in UF)

[lycium]

Code:

static float icosaSierp::baseVertices[] =
{
	 0.000f,  0.000f,  1.000f,
	 0.894f,  0.000f,  0.447f,
	 0.276f,  0.851f,  0.447f,
	-0.724f,  0.526f,  0.447f,
	-0.724f, -0.526f,  0.447f,
	 0.276f, -0.851f,  0.447f,
	 0.724f,  0.526f, -0.447f,
	-0.276f,  0.851f, -0.447f,
	-0.894f,  0.000f, -0.447f,
	-0.276f, -0.851f, -0.447f,
	 0.724f, -0.526f, -0.447f,
	 0.000f,  0.000f, -1.000f
};

i'm still really interested to know how your UF algorithm works btw

[David Makin]

I can send you the formula file if you like - it's just a text file.

[lycium]

hmm, actually i should be studying for my exams thanks for the offer, but i should exercise a little restraint -- my last two works were already done in "borrowed time" (i find it's much easier to be a productive programmer if i'm supposed to be doing something else!).

i'll have to look into it later, say novemberish

[David Makin]

OK !

[David Makin]

Just tried a Sierpinski pyramid rotation:

<a href="http://www.youtube.com/v/moCJUlQf0Fo&rel=1&fs=1&hd=1" target="_blank">http://www.youtube.com/v/moCJUlQf0Fo&rel=1&fs=1&hd=1</a>

Rendered 1 rotation in 101 frames at 320*240, took 1hr 40mins

Sorry only diffuse camera lighting and no shadows at the moment.

[lycium]

pretty interesting colouring, i suppose it's done based on the traversal steps?

btw, my lighting is also purely diffuse, but all possible light bounces are accounted for (unbiased estimation of infinite recursion) which is what illuminates the deep interior regions -- and what is responsible for the extreme render time :|

[David Makin]

In this case the colouring is based on the distances travelled on just the two final steps, the formula allows you to use more if you wish and also allows colouring based on the positions rather than the distances. I'm also hoping to add colouring based simply on the genetics.
Of course the 1hr 40mins was for 2 layers, 1 lighting and 1 colouring - it's possible to write it so this could be done in a single layer using UF's direct colouring option but I haven't got around to that yet
Thanks for the coords BTW, actually I had a "duh !" moment and looked up "icosahedron" in Google and found the coords on WiKi.

[David Makin]

Tried it using my escape-time IFS formula:

http://makinmagic.deviantart.com/art/Sierpinski-Icosahedron-65047470

[David Makin]

BTW there's a cheap trick you can use to approximate (very roughly) the effect you achieve by bouncing the light around and you can do it with just the normal first pass - instead of the light value going from 1 (full-lit) to -1 (completely the wrong way) change it so the scale goes from 1 (full-lit) to 0 (completely facing the wrong way) and reduce the ambient level somewhat - the result won't be as good as your image here but it will reduce the render time considerably

[lycium]

In this case the colouring is based on the distances travelled on just the two final steps, the formula allows you to use more if you wish and also allows colouring based on the positions rather than the distances. I'm also hoping to add colouring based simply on the genetics.

i'm not sure what you mean by the genetics, but colouring based on the last steps opens sufficiently many options (angles, velocity, distances, ...).

Thanks for the coords BTW, actually I had a "duh !" moment and looked up "icosahedron" in Google and found the coords on WiKi.

np, and you at least stated upfront that it was out of laziness

[lycium]

pretty cool how they look so similar! it's possible that i rendered mine with way too much recursion depth (10 or 12 iirc), which could also be responsible for the numeric precision issues i was facing...

BTW there's a cheap trick you can use to approximate (very roughly) the effect you achieve by bouncing the light around and you can do it with just the normal first pass - instead of the light value going from 1 (full-lit) to -1 (completely the wrong way) change it so the scale goes from 1 (full-lit) to 0 (completely facing the wrong way) and reduce the ambient level somewhat - the result won't be as good as your image here but it will reduce the render time considerably

ah yes, that's a standard trick used in game development a reference that immediately springs to mind is the mighty charles bloom, superstar game developer and theoretical physicist turned poker player, in his 3d rambles here: http://cbloom.com/3d/rambles.html (3-13-03 entry).