Page 755 - Kitab3DsMax

Chapter 27: Working with Compound Objects
Note
The Pick, Add, and Remove buttons become enabled only in the Modify panel. n
The object that is picked is added to the Blob Objects list, and each vertex of the object gets a BlobMesh
added to it. If the BlobMesh objects are large enough to overlap, then the entire object is covered with these
objects, and they run together to form a flowing mass of particles.
Setting BlobMesh parameters
The Size value sets the radius of the BlobMesh object. Larger sizes result in more overlapping of surround-
ing objects. For particle systems, the Size is discounted, and the size of the particles determines the size of
the BlobMesh objects. The Tension value sets how loose or tight the surface of the BlobMesh object is.
Small tension values result in looser objects that more readily flow together.
The Evaluation Coarseness value sets how dense the BlobMesh objects will be. By enabling the Relative
Coarseness option, the density of the objects changes as the size of the objects changes. The Coarseness val-
ues can be different for the viewport and the Render engine.
When a BlobMesh object is selected and applied to the picked object, each vertex has an object attached to
it, but if you apply a selection modifier, such as the Mesh Select modifier, to the picked object, then only
the selected subobjects get a BlobMesh object. You also can use the Soft Selection option to select those
subobjects adjacent to the selected subobjects. The Minimum Size value is the smallest-sized BlobMesh
object that is used when Soft Selection is enabled.
The Large Data Optimization option is a quicker, more efficient way of rendering a huge set of BlobMesh
objects. The benefit from this method comes when more than 2,000 BlobMesh objects need to be rendered.
If the viewport updates are slow because of the number of BlobMesh objects, you can select to turn them
Off in Viewport.

Cross-Ref
When BlobMesh objects are applied to a particle system, they can be used as part of a Particle Flow workflow.
The Particle Flow Parameters rollout includes a list of events to apply to the BlobMesh objects. Particle Flow is
covered in detail in Chapter 41, “Creating Particles and Particle Flow.” n

Tutorial: Creating icy geometry with BlobMesh
The BlobMesh object can be combined with a geometry object to create the effect of an object that has been
frozen in ice. Using the BlobMesh’s Pick feature, you can select a geometry object, and a BlobMesh is placed
at each vertex of the object. I suggest using an object with a fairly limited number of vertices.
To create the effect of an object covered in ice, follow these steps:
1. Open the Icy sled.max file from the Chap 27 directory on the DVD.
This file includes a sled model created by Viewpoint Datalabs.
2. With the sled selected, choose Create ➪ Compound ➪ BlobMesh, and create a simple BlobMesh
by simply clicking in the Top viewport. Set the Size value to 6.0. Then right-click to exit
BlobMesh mode, click the Pick button in the Parameters rollout, and select the Sled object.
3. Press the M key to open the Material Editor, and select the first sample slot. Change the Diffuse
color to a light blue, and set the Opacity to 20. Then increase the Specular Level to 90 and the
Glossiness to 40, and apply the material to the BlobMesh object.
4. Render the Perspective View window to see the final result. The sled is embedded in ice.

707