3D in Paintapp

Paintapp has an integrated 3D environment that lives right alongside your 2D artwork. A 3D scene renders into your document as an ordinary layer, so you can composite it with paint, photos, text, and filters using the same tools you already know. Under the hood the 3D system shares Paintapp's node graph, its GPU renderer, and its color-managed pipeline — it is not a bolted-on viewer but a first-class part of the app.

Import or build

Open a USD scene, or assemble one from scratch using 3D primitive nodes, lights, and materials.

Composite as a layer

The scene renders to a bitmap that stacks, blends, and masks like any other layer.

Preview & path-trace

A fast real-time preview for editing, plus a GPU path tracer for reflections, refraction, and true shadows.

How a 3D scene fits into a document

3D content is held by a 3D Stage. The stage is a node in the graph: it owns the scene (meshes, cameras, lights, materials) and renders it, through the active camera, into a 2D image. That image behaves like a normal layer — you can set its opacity and blend mode, put a mask on it, and stack 2D layers above and below it.

Because the stage is a node, 3D editing is non-destructive: moving an object, swapping a material, or re-aiming the camera simply re-renders the scene. If you are new to the graph, see Node-Based vs Layer-Based Editing, and browse the individual node pages under Nodes in the sidebar.

Getting 3D content in

The primary interchange format is USD (Universal Scene Description), the scene format used across film and animation pipelines. Paintapp reads USDA (.usda, the human-readable text form) as a first-class format, parsing its meshes, transforms, cameras, lights, and material inputs into a live scene.

Format	Notes
USD — `.usda`	Universal Scene Description, ASCII text form. The recommended way to bring a full 3D scene into Paintapp.
glTF Binary — `.glb`	The common web/real-time 3D delivery format, with PBR materials.
LightWave — `.lwo`, `.lws`	LightWave objects and scenes.
Cinema 4D — `.c4d`	Cinema 4D scenes.
Materials — `.mtlx`, `.srf`	MaterialX graphs and LightWave surfaces, used to shade geometry.

Bring a scene in the same way as any other file — File → Open (Ctrl+O) or drag it onto the canvas. See File Formats for the full list of what Paintapp reads.

Building 3D with nodes

You do not need an imported model to work in 3D. Paintapp ships a set of 3D nodes you can add to the graph and combine. The built-in primitives generate parametric geometry — change a parameter and the mesh rebuilds.

Node	Creates	Key parameters
3D Box	A rectangular box.	Size X, Size Y, Size Z
3D Sphere	A UV sphere.	Radius, Segments, Rings
3D Cylinder	A cylinder, tube, or cone (set the top radius to 0 for a cone).	Top Radius, Bottom Radius, Height, Segments, Start Cap, End Cap
3D Torus	A ring / donut.	Major Radius, Tube Radius, Segments, Tube Segments
3D Plane	A flat, optionally subdivided plane.	Width, Height, Width Segments, Height Segments

Alongside the primitives are a few nodes for placing and shaping content:

3D Card — takes a 2D image or layer as its input and places it as a flat plane inside the 3D scene, positioned in 3D space and correctly depth-sorted against other objects. This is the bridge between your 2D artwork and the 3D world — drop a painted layer or photo onto a card and fly the camera past it.
3D Transform — moves, rotates, and scales whatever feeds into it.
3D Mesh — a container for imported or generated mesh data.
3D Randomize Height — a simple experimental modifier that perturbs vertex heights.

The current node set focuses on primitives, transforms, and placement. General mesh modeling operations (bevel, boolean, subdivide, extrude) are not part of the node set yet — build complex models in a dedicated 3D application and import them.

Materials

Surfaces are shaded with a physically based (PBR) metallic-roughness material — the same model used by glTF and modern game and film renderers. The main controls are:

Property	What it controls
Base Color	The surface color, optionally driven by a texture map.
Metallic	Whether the surface behaves like metal (reflective, tinted highlights) or a dielectric (plastic, wood, skin).
Roughness	How polished or matte the surface is — low is mirror-like, high is diffuse.
Emissive	Light the surface emits itself; supports high-dynamic-range values so a surface can glow.
Normal / Occlusion maps	Add fine surface detail and baked contact shadowing without extra geometry.
Opacity & Alpha Mode	Opaque, cut-out (masked), or blended transparency.
Index of Refraction & Absorption	Glass and other transmissive materials — how light bends through the surface and how it is tinted on the way through.
Sides	Render the outside, the inside, or both faces of a surface.

Ready-made presets are available — including Metal, Plastic, and Glass, plus solid colors — as starting points. For custom looks, a MaterialX shader graph can drive the surface, and its parameters update live as you adjust them. See MaterialX for the full node library and how it renders in the preview versus the path tracer.

Lighting

Scenes are lit with USD-style lights. Each light has an intensity, a color, and an exposure control (each stop of exposure doubles the effective brightness, so you can balance lights the way a photographer would).

Light	Represents	Notable parameter
Distant Light	A sun or other far-away directional source — parallel rays.	Angular size
Sphere Light	A point or small round area light, like a bulb.	Radius
Rect Light	A rectangular area light — a softbox or window.	Width, Height

Lights can be narrowed with cone shaping for a spotlight effect, and point-type lights support distance falloff. When a scene has no lights of its own, Paintapp lights it with a default directional light plus ambient fill so it is never black.

Camera & navigation

You view the scene through a camera. Cameras support perspective projection (with a field of view derived from focal length and aperture, the way a real lens works) and, for scene cameras built in Paintapp, orthographic projection for technical / isometric looks. A file can carry several cameras, and you choose which one to look through.

The Camera Orbit tool navigates the view:

Action	Result
Left-drag	Orbit around the pivot.
Right-drag	Dolly (move toward / away).
Middle-drag	Pan.
Hold `Space`	Temporarily orbit while any 3D tool is active.

A Trackball option switches between turntable navigation (keeps the horizon level) and free trackball rotation, and you can choose to orbit around the whole Scene, the current Selection, or the world Origin.

The 3D tools

A dedicated 3D tool group appears in the toolbox whenever you are working with a stage. Direct-manipulation tools use an on-canvas gizmo colored by axis — X red, Y green, Z blue.

Selection

Pick objects; switch between Object, Face, Edge, and Vertex modes; loop-select edges and faces.

Move

Shortcut W — drag the arrows to translate. Axis space: Object, World, or View.

Rotate

Shortcut E — drag the rings to rotate. Axis space: Object or View.

Scale

Shortcut R — drag the handles to scale along the object's local axes.

Camera Orbit

Orbit, dolly, and pan the view (see above).

Real-time preview vs. path tracing

Paintapp renders 3D two different ways, and they complement each other:

Real-time preview (always on) — a fast GPU rasterizer draws the viewport while you work. It shades surfaces with the full PBR material model, supports transparency and two-sided surfaces, and can also show materials unlit or as wireframe. It is built for interactivity, so it does not compute shadows or reflections.
Path tracing (optional) — a GPU path tracer that simulates real light transport to produce accurate soft shadows, mirror and glossy reflections, glass refraction, and global illumination. It refines progressively, so image quality builds up over a moment. See the Path Tracer page for the full story.

Color management

3D rendering is fully color-managed. Both the preview renderer and the path tracer compute light in scene-linear color (physically correct, high-dynamic-range), and the result is converted into your document's color space on the way to the screen — through the same ICC and OpenColorIO pipeline used for everything else in Paintapp. That means a 3D layer sits in the same color world as your photos and paint, and it respects your working space and display profile. See Color Management for details.

The 3D environment and the path tracer are among Paintapp's newer, most advanced features and are still being refined. If a render looks off, the Path Tracer page and Color Management page cover the settings that most affect the result.