pChangeStyle

pChangeStyle sits inside a particle chain after pEmitter, pImageEmitter or other modifiers and before pRender. It neither creates nor renders particles: it receives an existing particle stream and changes selected appearance properties on eligible particles.

Keep Change Sets and Change Style conceptually separate. Change Sets reassigns Set membership for downstream logic. Change Style alters the visual representation and its style-specific controls. Either function can be used without the other.

The Style control uses the common particle styles shared with pEmitter and pSpawn. Point produces one-pixel particles; Bitmap uses an image delivered through a generated Style Bitmap input; Brush uses a brush resource; Blob produces soft cells; Line produces streak-like cells; Point Cluster creates groups of points. The captured Resolve 21 Inspector also exposes NGon, and child controls depend on the selected Style.

Style-specific controls are conditional. Point and Point Cluster use Apply Mode and Sub-Pixel Rendered. Bitmap reveals Style Bitmap plus Animate, Time Offset and Time Scale. Brush uses Brush and Use Aspect From. Line has its own Fade along the line length. Point Cluster adds Number of Points and Variance. These controls are not all visible at the same time.

Color Controls set base RGBA. Color Variance creates differences between particles, while Lock Color Variance ties channel variance together. Color Over Life is a different mechanism: its gradient changes the same particle across normalized age from birth to the end of lifespan.

Size Controls also depend on the selected style. Size sets the base scale, Size Variance randomizes it, Size to Velocity adds a velocity-dependent component, Size Z Scale links size to depth, and Size Over Life animates size across lifespan. Point has no normal Size control because a Point particle is defined as one pixel.

Fade Controls manage appearance and disappearance as a fraction of lifespan. A Fade In value of 0.1 represents roughly the first 10% of particle life. Do not confuse lifespan Fade In/Out with Alpha in Color Controls or with Line Fade, which controls falloff along the line cell itself.

Merge Controls and Blur Controls affect individual particle cells in 2D rendering and do not behave the same way for a 3D particle system. Blur, Blur Variance, Blur Over Life and Z Blur/DoF Focus should be treated as per-particle style controls rather than a replacement for a downstream post-render blur.

Conditions filters particles before pChangeStyle applies its change. Probability is evaluated for each particle on each frame. Start/End Age restrict the normalized lifespan interval. Set Mode chooses whether Sets are ignored, included or excluded. Those Conditions Sets are different from Change Sets on the Style tab.

Region adds a spatial event gate. Built-in Bezier, Cube, Line, Rectangle and Sphere regions are generated by the node and need no external data cable. Region = Bitmap creates a dynamic input for a 2D image/selectable channel, while Region = Mesh makes that logical Region socket accept a 3D mesh. It is not an ordinary Effect Mask.

Region Mode defines how the spatial event is evaluated, such as intersecting, being inside or outside, entering, or leaving the Region. This makes pChangeStyle useful for event-like restyling rather than only age-based transitions.

Particle-node order matters. For an effect that should appear to happen at the same collision used by pBounce, Blackmagic's particle reference places pChangeStyle before pBounce and gives both nodes the same Region. pChangeStyle sees the intersection before pBounce reflects the particle away from that surface.

Depending on configuration, pChangeStyle can expose three inputs with different meanings: the permanent Particles input, a dynamic Region input for Bitmap/Mesh Region, and a Style Bitmap image input for Bitmap particle Style. Style Bitmap defines how a particle cell looks; Region defines where or when the node acts.

Judge the final visual result through pRender and playback rather than a single still frame. pChangeStyle changes particle state; pRender turns that state into a visible 2D/3D result.