pImageEmitter

A normal pEmitter distributes births within its region, whereas pImageEmitter begins with a regular 2D grid sampled from the input image. X/Y Density sets sampling density, Alpha Threshold rejects unwanted pixels, and the image supplies color.

Density 1 on both axes means roughly one sample per pixel before alpha and region restrictions. An HD frame already contains millions of candidates; the same setting costs more at 4K. Begin with a sparse grid and increase detail afterward.

Alpha Threshold 0 can create particles even in a transparent background. They are invisible but still have a cost. A small positive threshold rejects zero alpha; a strong threshold also cuts away antialiased edges.

Create Particles Every Frame off produces one cohort. On produces a new cohort each frame, so Density, Lifespan and duration jointly determine accumulation. Initial Velocity/Rotation/Spin are assigned at birth.

Lock Color to Initial Frame controls the color of an existing grid. With it off, the grid can display later video frames; with it on, particles retain their birth color. For a clear comparison, start with zero velocity and identical geometry in two branches.

Style Bitmap is separate artwork repeated inside each particle. It does not replace the image sampled for the grid. Bitmap Region has another role: an external image channel restricts birth locations. Connector names matter more than memorizing dynamic socket colors.

Use Z Channel for Particle Z consumes the input’s actual Z channel. A regular RGB depth image does not automatically become that data. The basic lessons use a planar grid and pRender in 2D; a 3D path requires separate camera, depth and scale checks.

Sets assigns membership, Style controls appearance and Region restricts births. Neither set membership nor style opacity is equivalent to particle deletion. Use pKill for conditional death and Lifespan for ordinary lifetime.

All eight original PNGs are included in the Inspector. Time Lock and NGon are retained as real entries in the captured interface; details not described in BMD21 are not claimed as verified. Recalculate the sequence from its start after changing birth or motion settings.