3ds Max 9 Bible
BlobMesh objects are simple spheres. If you have only one of them, they aren't interesting at all, but if you get them together, they run into each other much like the metal mercury. This makes them an ideal choice for modeling flowing liquids and soft organic shapes.
BlobMesh objects are used as sets of objects rather than as individual objects. If you click the BlobMesh button in the Compound Objects subcategory and then create a BlobMesh in the viewports, it appears as a sphere with the radius set using the Size parameter. The real benefit comes from clicking the Pick or Add buttons below the Blob Objects list and selecting an object in the scene.
| Note | The Pick, Add, and Remove buttons become enabled only in the Modify panel. |
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 surrounding 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 values 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 MeshBlob object. You can also use the Soft Selection option to select those sub-objects 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 35, "Creating Particles and Particle Flow." |
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:
-
Open the
Icy sled.max file from the Chap 18 directory on the DVD. This file includes a sled model created by Viewpoint Datalabs. -
With the sled selected, choose Create
Compound BlobMesh, and create a simple BlobMesh in the Top viewport. Set the Size value to 6.0. Then click the Pick button in the Parameters rollout, and select the Sled object. -
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.
Figure 18.10 shows the resulting sled, all ready to be defrosted.
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