It's hard to describe with words, but here goes.

Base Shape
The ball was constructed by first creating an icosahedron from scratch. I used the arc tool with the center at the origin, the start at 0,0,1 and the end at 2,0,1. This gives you a perfect arc along one edge of an icosahedron with an angle of atan(0.5) or 26.565 degrees. Then just array these arcs into place.

Dimples
Next create one dimple by scaling a small sphere along one axis. Then use curve-array and select one of the arcs to arrange the dimple along that path. You'll need some more arcs that cross over the surface from one edge to the next. And do some more "curve-arraying" to create the dimples in the middle.

Cutting
Once all the dimples are in place do a boolean subtract with a unit sphere to cut them out. This operation took about 10 minutes on my PC and it looked as if MoI locked up, but it was actually working hard to calculate all the intersections and stuff like that. This operation failed to include all the dimples -- some were simply ignored for some reason. I was able to resolve this by scaling up by a factor of 10. I read this tip in one of the posts here.

Smoothing
Then, and this is important, select the sharp edges and fillet them with a G2 Blend not Circular. This rounds off the edges and makes the ball look better. I also had problems here because the fillet would fail with the radius that I needed. And some dimples were ignored again even with a very small radius. And those dimples didn't lie on a visible border either.

I may have left out a few things, but that's the basic workflow. In the end I resorted to modeling one section (i.e., one face of the icosahedron) and arraying them into place. After joining all 20 pieces, boolean ops no longer worked. This is not what I wanted. I'll have to go back and try to model it as one piece so I can do a cut-away rendering.

Just a little question for a newbee golfer:)
All golf ball have the same number of dimples or there exist some different model?

Else cool tut!
I will try to find another solution for the fun :)

They have different numbers and different patterns.

Wow, this is quite impressive!

Thanks for taking the time to describe your process.

I imagine there is many ways to do this, I initially though you have used small spheres in an array following 3d spiral curve.

It interested me because I have a white cell (immune system) project to illustrate, which somewhat share a similar construction, being objects scattered around a sphere.

I'll probably end up drawing it manually... :-)

-Marc

Thanks. The spiral curve approach could work, but I haven't seen that pattern on a real golfball. But it may eliminate most of the problems I had during modeling.

You could also use MoI. Just model the cell, then snap lil spheres to the surface. Here's a post by MG that shows how to make a blobby-cel shape:

http://www.moi3d.com/forum/index.php?webtag=MOI&msg=415.2

helo

Why do I get "check console" blender message?

Hi Andras, I think that Anthony's blender import script needs to have the "Weld vertices along edges" option in MoI turned off when you export, otherwise it will try to put up a warning message. My guess is that is what is happening to you.

In MoI expand the mesh options dialog by using the arrow in the lower-left corner, and uncheck that option, and then you should be able to use that mesh data with Anthony's script.

- Michael

This is really fantastic. It looks like I just might be using this importer script for my characters. To get OBJ imported models to look right I learned that I had to give the model an Edge Split modifier, which helped a lot.

Thanks. Just remember that if you apply the EdgeSplit or any other modifier, the true normals will be deleted, and averaged normals will be calculated. This will defeat the purpose of my script.

Thanks Michael it is work.
(just if I use only N-gons some faces will be missed but if I use only Triangles than it is perfect)
thanks!

Sweet plug-in anthony! Works great.

Thank you :)

Hi Anthony
Thanks for this plugin.

It seems that I'm to stupid to get good results with it.
I just tested it with a freeform surface, used "N-gons" and turned off "weld vertices along edges" and "Angle" is 12 (degree?), see "Freiflaechentest_N-Gones_001.jpg".
One test is with "triangles only" insteat of "N-gons", see "Freiflaechentest_only_triangles_002.jpg".

I love Moi but it would be useless for me if I never can import proper models from moi into another 3d software like blender.

I hope somebody can help me for a proper export-import process ?


Kind regards
Alain

Hi Alain, that's the kind of shading problems that you can see if vertex normals are not being imported properly.

Are you sure you are using Anthony's importer?

One thing to note is that after installing Anthony's importer, you must pick it off of the import list separate from the default LWO importer which will still show up there.

Anthony's one is labeled MoI with Normals, as shown below. Make sure to pick that one and not the default LWO importer.

Also if you can post the 3DM model file of the thing you are trying to export, that would make it easier for me to test with it directly and show you what to do.



- Michael

Hi Alain, also you can try the OBJ importer from this post:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3164.11

The default OBJ importer for Blender was throwing away the vertex normals at the end of the load, I modified the one in the post above to maintain the vertex normals which helps to get much nicer smooth shading.


You may also want to use the "Divide larger than" parameter in the meshing options, to force some additional divisions of the polygons in your model there. When you have triangles that span a pretty large length of the model that can tend to make for more rendering artifacts.

If you enter in a distance value for "Divide larger than", any polygons larger than that distance will be broken down into smaller pieces which tends to render better even without vertex normals being present.

If you post your model, I'll show you an example with it.

- Michael

Hi Michael

Thanks for your quick answer :)

Yes I use the importscript as you discribed it.
Here is the *.3dm file.

I hope it helps.


Alain

Thanks Micheal, it was the option "divide larger than" which gave me the possibility to divide those long triangles.

It's still not quit perfect (see attachement, use triangles and quads. using n-gons is a little bit better).

Edit:
I used the Import-Script of Anthony. Your modified OBJ-Import gives me about the same results as Anthony's script.

Alain

Hi Alain,

> It's still not quit perfect (see attachement, use triangles and
> quads. using n-gons is a little bit better).

It looks like there were not a lot of polygons created on that tightly curved area.

What parameters are you using, still only an angle of 12?

If you want to have a smoother look on curved areas, reduce the angle a bit more (move the slider towards the "more polygons" side a bit), bring it down to something like 8 and that will make more polygons on curved areas and give it a smoother appearance.

The angle parameter helps to make more divisions on tightly curved areas - if you have areas that are larger and more shallowly curved then also use a distance value in "Divide larger than" to help refine those kinds of areas more.

Blender's renderer seems to be somewhat sensitive to having much change between each polygon, so you may need to produce a fairly fine mesh if you want to have a super smooth looking rendered result. Some other kinds of renderers are not quite as sensitive.

- Michael

Hi Alain, also in your last image there it is possible that you are getting some general rendering artifacts such as "self shadowing" on polygons that are nearly vertical to the light source or things similar to that.

It is possible that you could solve that by tweaking some kinds of rendering parameters, or maybe by moving the light over a bit or things like that.

If you produce a denser mesh by using a tighter angle, it can help to make some kinds of rendering artifacts be reduced.


Remember - when you're dealing with polygons the data you are working with is actually made up of some completely flat facets, it is only some kinds of display tricks that make things appear as if they were actually smooth.

If you use more polygons, some of those display tricks get a bit higher accuracy because the actual faceted shape begins to more closely approximate a true curved surface instead of a faceted one.

- Michael

Hi Michael, thanks for your support.

I get the best result with the "Divide larger than" parameter.

Good to know it is renderer depending. I just tried it with the Blender internal renderer but I will never render it with it for a final image.

What renderers work good with Moi imported models ? Yafaray ? V-Ray ?
I also have been reading the thread about the octane renderer, how far is radiance with his tests ?


Kind regards
Alain