Vertices exported as particles (rollover image)

 

 

Vertices of poly meshes can be rendered as particles via the C4DtoA Tags > Arnold Mesh Particles tag.

 

 

The tag can be assigned to Polygon Objects and object generators (e.g. Cloner). When the tag is added, the poly mesh is not exported, only the vertices are translated. The particle system settings are displayed in the tag, each setting of a normal particle system is available (e.g. render mode, instancing, volume step size, etc.). Note that the Arnold tag shows no parameters in this case.

Particle system settings as displayed in the Arnold Mesh Particles tag

 

Selection

A Polygon, Edge or Point Selection tag can be assigned to render particles only at the selected vertices. Multiple Mesh Particles tags can be added to the object with different selections.

Render Points As

Choose to render vertices as Points, Spheres, Quads or any Custom shapes.

Custom Shapes

Besides the built-in modes, you can use any shapes from the scene to render particle instances with by selecting the custom render mode and adding the shapes to the Custom Shapes field.

Shape Mode

If multiple custom shades are defined for instancing their order can be specified via the Shape Mode option. The available modes are:
  • sequential: shapes in the defined order (as they appear in the Custom shapes field).
  • random: uses the Random seed to define a random shape order.
  • blend: divides the shapes into equal amounts.
  • first: uses only the first shape. 

Radius Multiplier

Applies a global multiplier to the radius size of the particles.

Min Pixel Width

If this value is non-zero, particles in points mode with a small on-screen width will be automatically enlarged so that they are at least the specified size in pixels. The enlargement fraction is then used in the particle shader to adjust the opacity so that the visible thickness of the particle remains the same. For a given number of AA samples, this makes it a lot easier to anti-alias very small particles, at the expense of render time (because of the additional transparency/depth complexity). Good values are in the range of 0.2 to 0.7. Values closer to 0 are faster to render but need more AA samples. So if your scene already uses very high AA settings, you should use a low value like 0.1.

Channels

Allows you to control the radius and rotation of the particles.

Radius Type

Change the radius of the particles. Choose between constant, random, vertex map or polygon area.

Random Seed

Sets the particle radius seed value. You can set the same value in different mesh particles to generate the same particle radius on different poly meshes.

Vertex Map

Attribute for connecting a vertex map to drive the radius of the particles.

Rotation Type

How the particles are rotated. Choose between constant, random or vertex map. Currently only works with Custom shapes.

Random Seed

Sets the particle rotation seed value. You can set the same value in different mesh particles to generate the same particle rotation on different poly meshes.

Rotation X,Y,Z map

Attributes for connecting vertex maps to drive the rotation of the particles.

Export vertex maps 

Allows you to export any vertex maps of the source object.

It can be useful for example if you have a photo scan point cloud where the R, G, B channels are imported as vertex maps. Then they can be exported with this option and read via a Vertex Map shader in the shader network.

 

 

 

Pepe model by Daniel M. Lara (Pepeland)

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