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I know there are some mandelbulb raycasting implementations for ultrafractal 5, but i do not know where to find, can anyone assist ??!?!

i was using the reb.ffm formulas, but they do not seem to allow adjusting the iteration depth ... :/
 ??? :angel1: :angel1:

It's only WIP but blb is using my formula from here:

Edit: Please see here: http://www.fractalforums.com/mandelbulb-implementation/update-to-the-mmf-wip-formula-for-ultra-fractal/ (http://www.fractalforums.com/mandelbulb-implementation/update-to-the-mmf-wip-formula-for-ultra-fractal/)

I should be releasing an updated version soon, though it will be a new formula in the same ufm file rather than an update to the existing formula because I've found loads of optimisations/improvements and adding them to the current version in a backwardly compatible manner would be too messy :)

Note that there are still one or two things that don't work properly and some hangovers from the fact that it was started from my mmf4.ufm:3D IFS formula (such as colour by genetics).

Note that for best results set the max iter to a high value (e.g. 400) and to get more detail reduce the "solid threshold" value.

I've been using your formula quite extensively in the last weeks. I found that for global views (not zoomed), 8 to 12 iterations is enough, with an Accuracy of 2, and a Solid Threshold of 1E-2 to 1E-3.

For zooms, I sometimes need to set 100 to 500 iterations : the more you zoom into "whipped cream" areas the more you need iterations. And a solid threshlod sometimes as low as 1E-9, but generally 1E-5 to 1E-7 is enough. To get rid of artifacts, I occasionnally set the accuracy to 3 or 4.

When you publish you formula in the database, it means I won't be able to use my existing ufr's if I want to take advantage of the last optimisations?

Cheers

bib

Essentially correct, though I don't know if I'll ever upload it to the UF database, as I've said before it's only a WIP towards creating a set of ray-tracing classes for UF. I will make the updated version available for download from my site though.
However all the important parameters will remain the same so manually setting the new formula to the same as an existing UPR using the old one should not be too difficult (just a little tedious).

how do i set up the coloring/lighting ?

The object is coloured as "inside".

With the "Lighting+colouring" colouring methods then use mmf4.ucl:3D colouring direct as the inside colouring - the rest of the parameters are basically in the main formula rather than the colouring. If you wish to control the RGB channels in the lighting separately then you can do so by choosing the "advanced" lighting option - but be sure that this is set to match in the formula and the colouring. If using "lighting+colouring" in normal combined light mode then you should set UF's standard maxiter to 4 (or more), if using the advanced method (split RGB) then you need to set UF's maxiter to 8 or more.

Here "Note that for best results set the max iter to a high value (e.g. 400) and to get more detail reduce the "solid threshold" value." I was referring to the max iterations parameter in the formula rather than UF's standard max iterations formula parameter - UF's standard formula max iter should be set to either 1 (for plain lighting) or 4 (for lighting+colouring) or 8 (for lighting+colouring with advanced lighting enabled).
Also if colouring by just "Lighting" alone then you should use mmf.ucl:MMF 3D colouring rather than the colouring formula from mmf4.ucl

Actually, the iteration depth is the same as for ANY standard Ultrafractal ufm, and can be set to anything from 0 to very, very large. Look on the Formula tab. There is an entry box for maximum iterations. You set the value there. This is assuming you are using the correct formula, which is found in reb5.ufm, and is titled "3D Fractal Raytrace". For best results this formula should always be used with the the coloring formula "3D Fractal Coloring Direct", which is in reb5.ucl. I have not updated my current version of 3D Fractal Raytrace to the UF database in a while. There are a number of changes that I am still beta testing. I will post a message to FractalForums when I am finished beta testing.

After I update my formulas to the UF database I will post some sample Ultrafractal uprs here as demos.

The UF database has been updated with my most recent version of 3D Fractal Raytrace. I will be posting a short tutorial and some examples soon.  :D

You will need Ultrafractal 5 to access the formulas.  :alien:

@fractalrebel

you can add them as demos to the ultrafractalwiki database

or, just publish the uf files, i will include them on the wiki page

Trifox, you have the wrong link  :( in ultrafractalwiki for my Ultrafractal tutorials. The link should be:

http://www.hiddendimension.com/Tutorials/Tutorials_Main.html  :dink:

I will add a full tutorial to my website. The main code is in reb.ulb, which changes frequently, as it is my main object library file. It is also large (currently about 2 Meg). Objects from common.ulb and dmj.ulb is also used. Consequently, I don't think putting the files on the wiki page is a good idea. They are all in the Ultrafractal database, and anyone who owns Ultrafractal has access to them.

Hi Ron, I think Trifox meant example parameter files :)

@rebel yes, i meant the parameter files, some example  copy&paste content for the wiki :D as a starter for beginners

i will correct the link to your page, you have a direct link for the page with the wrong link ?!

FractalWiki already has a direct link to my Ultrafractal Tutorials, but the link is wrong. It should be:

http://www.hiddendimension.com/Tutorials/Tutorials_Main.html  

It is in the section on tutorials:

Online tutorials
Fractal Marbles
Ron Barnett's Fractal Formula tutorials - this has the wrong link
Ron Barnett's UF5 Challenges
Janet Parke's tutorials
Zoorekas tutorials

My tutorials already have parameter files, as will the new one for 3D Fractal Raytrace. Do you still want a separate set of parameters?

Hi everyone,

I have added a tutorial for 3D Fractal Raytrace (UF5) to my tutorials pages on my website. ;) There are snapshots of the user interface, three Mandelbulb examples and several other 3D/4D fractal examples, complete with parameter files that the user can copy and paste. The general link to the tutorials is:

http://www.hiddendimension.com/Tutorials/Tutorials_Main.html

While the specific link to the 3D Fractal Raytrace (UF5) tutorial is:

http://www.hiddendimension.com/Tutorials/3DFractals/3DFractalRaytraceTutorial.html

 :D

i have corrected the tutorials link to your site, i would like to put the formula .upr files on to the wiki with images, are you ok with that ?!
as it shall also serve as parameter collection for ultrafractal
 

Please feel free to use any any of the contents of the tutorial for posting to the wiki.

thank you, but i have to insist: setting of iteration depth is not working, the mandelbulb 8th order gets low resolution inner bulbs, wenn zoomin in, i have entere an iteration depth of 250, and nothing changes, do i have to increase the additional accuracy ?!  :hmh:

My formula or Ron's ?
In mine:
No, not the accuracy, you have to reduce the distance estimate threshold distance - when using distance estimator solid is not based on iteration but based on the distance to inside and is solid when the distance to inside is less than the threshold you specify.
You only need to *increase* the accuracy if there are errors in the render such as missing bits - often an accuracy of 2 is sufficient but sometimes up to 4 is required (or higher on some Julia Sets).

In Ron's again for more detail you'll need to reduce the distance estimate threshold or at least modify the parameter that will do so.

Trifox,

Try setting iteration number to 3. You will see it is working. As Dave has pointed out, greater detail in my formula is obtained by decreasing the closeness parameter. Iteration number does not affect how close the surface is approached. Approach to the surface stops when the estimated distance to the surface is less than closeness. In the code, closeness is called epsilon. This follows the Hart, Sandin and Kauffman algorithm.

When you zoom in you will probably have to decrease the closeness to maintain a good resolution level.

The first image shows a zoom into an 8th power mandelbulb with closeness = 1 (the default value). Pretty nasty looking. The second image has closeness = 0.045. This is more what we might expect. Trifox, I think you just did a bit of beta testing. I will modify the formula so that closeness depends upon the zoom. This formula has built-in version history so old uprs will still render correctly, while new one will use the modified closeness. I will put a message on this thread when the modification has been tested and uploaded to the UF database.

shame on me !

i just played around with the excellent gpu version made by subblue, and i understand, your iterations work just fine, i wasnt used to the behaviour of the iteration increase, was
hoping the would get more detail, but you have to zoom in ! i think it is another side effect of the whippey cream behaviour

so, i will now subclass your 3d renderer, and quat classes, to provide them with an "iterationStart" event, i try to hold it as compatible as possible, to use
all your existing formulas in an formulat alternation process... i have played with it within the realtime gpu version, had was much fun and needs to be implemented
in ultrafractal to make mystic 3d objects movies :D

very cool! thx for patince!  O0 :angel1:

I have updated 3D Fractal Raytrace to autocorrect the closeness on zooming. I also added a bit of explanation to the tutorial.

Here is a 400x zoom into an 8th power Mandelbulb. Its comprised of two layers. A distance layer provides the color and the raytrace (Phong) layer provides the highlights.

Here is a little demo that shows the effects of maximum iterations of an 8th power mandelbulb. The top two panels show the mandelbulb with no zoom. The upper left panel is with maximum iterations = 6 and the upper right panel is with maximum iterations = 1000. Not a lot of difference, although the higher iteration panel shows more detail. With a 9x zoom substantial differences are seen. The lower left panel has maximum iterations = 6. Stair steps can be seen from the low iteration value. The lower right panel has maximum iterations = 1000. There is considerable more detail, and regions which in the left panel had little detail other than the stair steps, now have fractal detail.

yeah, thank you very much for explaining, i think this is one of the essentials we have to learn about the behaviour ( when browsing ) by now i had some time to experiment with a gpu version of those things, and
it is enjoyable, but sometime dissappointing that iteration increase does only affect (non-whipped-cream ?) areas ...   :angel1: ^-^