Download: http://www.chaosgroup.com/forums/vbulletin/showthread.php?t=45994
Example result: http://www.ylilammi.com/graphics/MilkCoral.jpg
Example scene (max 2009): http://www.ylilammi.com/BerconMetaball/MilkCoral.7z
Source code for NON-commercial use: http://www.ylilammi.com/BerconMetaball/BerconMetaball\_Source\_2009\_26\_05.7z
I’ve tested it on all compatible Max versions (9/2008/2009/2010, 32bit/64bit) but very briefly, so its possible there are some major bugs in there. Metaballs are only compabile with VRay 1.50.SP3a.
Please report all bugs found here or email me.
INSTAL!
1. Select the correct version (Max 9 and 2008 use the same file).
2. Copy it to your 3dsmax/plugins/vrayplugins/ folder. ← VRAYPLUGINS/ not plugins/
3. Start 3ds max and you’ll find BerconMetaballs under VRay objects (same place where VRayPlane is)
USAGE!
Very similar to 3ds max’s own Blobmesh, but now viewport preview, shows up in render only. Just point
the metaball to some mesh or particle object.
Why is this better than the Blobmesh? Because:
1. Requires very little ram, its possible to render 10 000 000 particles with ~2GB ram
2. Perfectly smooth, no meshing artifacts
3. Supports true 3D motion blur
4. Very fast preparation time, there is no need to generate the mesh at all when starting rendering, just
render things you see and not those you don’t
LOOK AND FEEL!
Metaballs are points which have falloff radius, it starts from 1.0 when the distance to the point is
0 and fades of to 0.0 when the distance to the point is same as the radius. This function is not linear
its determined by the Distance Function. The surface is raytraced and lies where the density (all metaballs
distance summed together) of the field is the Threshold value. What this means:
High threshold = Slower to render but more metaball effect
Low threshold = Faster to render but less metaball effect (more like normal spheres)
When using high threshold the metaballs are smaller, compensate this with higher radius.
The “Use average distance” option produces smoother surface when used with fluid simulation particles, this
means that the particles must be evenly spaced to produce good results. You can use it with just normal
chaotic particles but it might result in artifacts. To reduce these artifacts play with the Cutoff and Trim
paramters.
Cutoff and Trim parameters affect the result only when “Use average distance” is checked.
SPEED!
You can control the quality with a single parameter and thats the “Step length”, its better not to touch the
Max error, good values for the Max error parameter are between 0.001 and 0.0001. It doesn’t have that much of
an effect to render times. High max error values produce artifacts like black dots.
Step length determines how large steps we take when tracing the metaballs. Bigger steps mean we might miss some
metaballs but it renders faster. Generally values that are 1/10 of the metaball radius produce fairly accurate
results very fast. For example Radius: 5.0 and Step length 0.5 would be a good starting point to start tweaking.
ADVANCED!
Bounding Volume Hierarchy is an acceleration data structure to search the points fast. It doesn’t affect the end
result at all, it simply makes metaballs render faster or slower. Max tree depth determines how large the data
structure is, it goes in exponent of two so depth 15 means maximum number of leaves is 2^15. Leaf length the maximum
dimensions of single leaf and leaf size maximum number of points in single leaf.
Its generally better not to touch Max tree depth at all, higher values might use more ram and depth 15 should
be enough even for few million particles.
Play with the Leaf Length and Leaf Size if you want to optimize your render times.
- Jerry
