Replicate3D

Replicate3D has two fundamentally different input roles. The required Destination carries a 3D scene or geometry with vertex positions or 3D particle positions. Input[#] carries the 3D geometry or scene that will be placed at those positions. Destination is not the object being copied, and a source Input does not create the distribution by itself.

Connecting the first source Input creates another Input[#], so several source scenes can be alternated or selected randomly. Blackmagic documents this as a dynamic sequence of source inputs; at least one source Input is required in addition to Destination.

Step is not a current-instance selector. It thins the Destination positions: Step = 1 uses every position, while Step = 3 uses every third position. On dense destination meshes this is one of the first performance controls to consider because fewer placement positions normally mean fewer replicated objects.

On parametric geometry, Step can also behave like a coarse pattern selector because different values sample different subsets of ordered vertices. It is not a masking system, however, and the visible pattern depends on Destination vertex order.

Blackmagic also documents a PointCloud3D edge case: once a point cloud is made renderable, one visual point can be represented internally by multiple points. Step plus a small translation offset may therefore be required for one replicated object per visual point. Exact offsets are object- and scale-dependent and should be verified in the target build.

Input Mode matters only when multiple Input[#] sources are connected. Loop walks through the source scenes in sequence and repeats them when there are more destination positions than sources. Random assigns a source to each position deterministically from the Random Seed on the Jitter tab. With only one source connected, Loop and Random should look the same.

Particle destinations add one more caveat: particle IDs can change when particles die and are reborn. The manual warns that this can change copy ordering/assignment, so a critical sequence should not assume particle ordering is permanently stable.

Controls / Time Offset shifts source-geometry animation by a fixed amount per copy. This is not random jitter: an animated source can be sampled at a different time by successive copies, which is useful for staggered animation or successive frames on textured geometry.

Jitter / Time Offset is a separate control with different semantics. It adds random time variation driven by Random Seed. For diagnosis, set Jitter Time Offset to zero first, verify the deterministic Controls Time Offset, then enable the random stage.

Alignment controls copy orientation relative to Destination normals or particle rotation. Not aligned preserves the orientation of the input mesh and is the safest baseline when you want to validate the placement distribution before introducing surface orientation.

Aligned uses the destination point normal and reconstructs an up vector. Blackmagic notes that it can work well with certain organic/unwelded meshes but may show a gradual rotational shift on planar geometric meshes. The manual also recommends using this alignment close to the origin before unnecessary transforms and validating it against the actual topology.

TBN Aligned builds orientation from the tangent, binormal and normal at the destination point. It is generally more stable for particles and geometric shapes, but coincident unwelded vertices can carry different normals/TBN frames and therefore produce different orientations. That is a topology/surface-data issue, not necessarily a Replicate3D fault.

Color primarily concerns particle color. Use Object Color ignores destination particle color. Combine Particle Color keeps the source mesh shader and modifies its diffuse color using the particle color. Use Particle Color replaces the source mesh shader with a default shader whose diffuse color comes from the destination particle.

On a mesh-only Destination without meaningful particle color, do not treat the Color menu as a universal vertex-color remapping system. Use Object Color is a clean baseline; particle-color behavior should be tested on an actual 3D particle destination.

Translation, Rotation, Pivot and Scale are base transforms applied to the replicated copies. Rotation Order controls Euler order. Scale Lock X/Y/Z switches between uniform scale and independent X/Y/Z values. Tune these separately from Alignment so a base transform does not hide an orientation problem.

The Jitter tab adds seed-driven variation. Random Seed makes the pattern reproducible, while Reseed/Randomize generates a new seed. Translation, Rotation, Pivot and Scale Jitter vary the matching transforms, while Jitter Probability visible in the captured Inspector limits the fraction of copies receiving jitter.

Pivot Jitter applies to the additional jitter rotation and does not replace the base Pivot/Rotation controls. If an object swings around an arc instead of rotating locally, inspect the source origin and both pivot scopes independently.

Scale Jitter with Lock X/Y/Z enabled produces uniform size variation. Disabling the lock allows independent axis variation. Large non-uniform jitter can deform identical source geometry heavily, so small values are usually a better production starting point.

Replicate3D is not Duplicate3D. Duplicate3D creates a series of copies from its own copy/transform logic; Replicate3D consumes an existing set of destination positions from a mesh or 3D particle scene. For a simple linear array without a destination field, Duplicate3D is usually simpler.

Replicate3D is also not a particle generator. A pEmitter/pRender or other particle chain creates and processes particles; Replicate3D only consumes their 3D positions when a suitable scene3d destination already exists.

Output remains a classic Fusion scene3d stream. It can feed Merge3D, Transform3D, Renderer3D and other compatible 3D tools. It cannot feed MediaOut or a normal 2D effect directly; the scene becomes pixels only at Renderer3D.Image.

Bundled screenshots confirm the captured Inspector contains Step, Loop/Random, Time Offset, Not aligned/Aligned/TBN Aligned, the three Color modes, base transforms, Random Seed/Reseed, Jitter Probability and transform jitters. Live execution of these controls in Resolve 21/21.1 was not performed in this authoring pass and remains a separate target-build verification gate.