Projector3D

Projector3D has two different data domains at its inputs. The orange SceneInput accepts an optional classic Fusion scene3d stream while the white ProjectiveImage accepts a normal 2D image. Its Scene output remains scene3d. ProjectiveImage can therefore come from MediaIn/Loader/Background, but Projector3D.Scene must not feed MediaOut directly; RGBA pixels appear only after Renderer3D.

ProjectiveImage is documented as an optional socket at the topology level, but an actual image-projection workflow needs a 2D source. It is not a material socket and should not be treated like Shape3D.MaterialInput.

In Light mode Projector3D behaves like a spotlight-style light modulated by ProjectiveImage. The projection participates in diffuse/specular response, depends on normals/material lighting, and requires lighting to be evaluated in the Viewer/Renderer3D. Projective-image alpha does not cut geometry in Light mode.

Ambient Light mode routes the projected image through the ambient lighting contribution. This is useful when you want the projection pattern without the normal directional diffuse/specular behavior of Light mode. Alpha still is not a geometry cutout in this mode.

Texture mode is a fundamentally different path. It is designed for relightable texture projection through a Catcher material. Only geometry/materials using the Catcher output receive that projection, and ProjectiveImage alpha can participate in clipping the texture result. Texture mode should not be described as merely another kind of light.

Fit Method controls how ProjectiveImage aspect is placed inside the projector frustum. Inside preserves the whole image and can leave unused sides; Outside guarantees frustum coverage at the cost of crop; Width/Height locks one dimension; Stretch fills the complete area by changing aspect. This is separate from Angle.

Angle changes the projector frustum itself. Historical documentation often says cone, but Projector3D forms a square light/projection pyramid whose apex is at the projector position. Diagnose Angle and Fit Method independently: Angle changes the frustum, Fit Method changes image placement inside it.

Decay Type defines distance attenuation: No Decay, Linear, or Quadratic. It is a distance property and does not replace Angle/Fit. No Decay is a useful starting point for aim/fit tests before distance falloff is introduced.

Projector ID primarily matters in Catcher workflows: a Catcher can accept only projectors with matching IDs. The ID does not need to be globally unique and should be thought of as routing/filter metadata rather than a node name.

Projector Priority is used when multiple projections are accumulated, such as Catcher Blend. Higher priority is layered above lower priority. It is not a universal 3D z-order or a generic winner-selection rule for all Projector3D nodes.

Project on Back Faces allows the projection to affect back-facing polygons. It can be required for two-sided geometry, but it can also create unwanted spill through rear surfaces, so establish the front-face result first.

Projector3D uses a spotlight-like model and supports shadow maps. Map Size controls resolution, Bias addresses depth/self-shadow conflicts, and Sampling/Softness controls filtering. These are independent: more softness does not repair wrong bias, and a larger map does not make a shadow physically softer.

Force All Materials Non-Transmissive is more than an opaque-material switch. Blackmagic's tool reference describes an optimized Z-only shadow-map path: faster and lighter, but without transmissive/stained-glass-like colored shadows.

The current Resolve 21 Inspector shows Softness modes None, Constant, Variable, and Variable Fast. Older Blackmagic references document None/Constant/Variable plus the conditional Constant Softness / Softness Falloff / Min / Max controls. Variable Fast is visible in the current UI, but its exact target-build performance/visual tradeoff should be confirmed live.

Projector3D has a full directional transform: Translation places the frustum apex, Rotation aims it, Pivot changes the transform center, and Use Target aims toward Target Position. Unlike PointLight, rotation is functionally important here.

When SceneInput is connected inline, the Projector3D common Transform also affects the incoming 3D scene. This is the usual classic-3D parent-transform caveat; keep Projector3D on a separate Merge3D branch when projector motion must remain independent of geometry.

Projector3D and Camera3D projection overlap in purpose but are not interchangeable. Camera3D is preferable when projection must match camera film back/aperture/clip behavior; Projector3D is preferable as a custom projected light with direct Color/Intensity/Decay/Shadows controls.

Troubleshoot in five isolated layers: source image → projection mode → frustum/fit → transform/aim → receiver/material/renderer. Changing all five together makes it easy to misdiagnose fit as texture failure, shadow bias as geometry trouble, or disabled lighting as a broken projector.