{ "id": "geometry_comp", "name": "Geometry COMP", "displayName": "Geometry COMP", "category": "COMP", "subcategory": "3D", "version": "Available since TouchDesigner 2019+", "lastUpdated": "2026-02-21T00:00:00.000Z", "sourceFile": "", "url": "https://docs.derivative.ca/Geometry_COMP", "description": "The Geometry COMP is the bridge between the SOP (Surface OPerator) world and the 3D rendering pipeline. It wraps SOP geometry — boxes, spheres, procedural meshes, point clouds — and exposes it for rendering via a Render TOP. The Geometry COMP controls transform (position, rotation, scale), material assignment, instancing, and display properties. You wire SOPs into its input; the Render TOP references it by path in its Geometry parameter.", "summary": "Wraps SOP geometry for 3D rendering. Provides transforms, material assignment, instancing, and LOD control. Referenced by Render TOP via path parameter, not wire connection.", "details": "The Geometry COMP is a container in the COMP family that holds a SOP network and presents the resulting geometry to the render pipeline. Its Transform page controls world-space placement. The Material parameter links to a MAT operator for shading. The Instance page enables GPU instancing driven by CHOP channels, Table DATs, or other data sources — allowing millions of copies of the geometry to be rendered in a single draw call.", "usage": "1. Place a SOP operator (Box SOP, Grid SOP, etc.) in your network.\n2. Place a Geometry COMP.\n3. Wire the SOP output into the Geometry COMP input 0.\n4. Create a Camera COMP and a Render TOP.\n5. Set the Render TOP Camera parameter to the Camera COMP path.\n6. Set the Render TOP Geometry parameter to the Geometry COMP name (e.g., 'geo1').\n7. Add a MAT operator (Phong MAT, PBR MAT) and set the Geometry COMP Material parameter to it.", "tips": [ "Use '*' in the Render TOP Geometry parameter to automatically include all visible Geometry COMPs at the same level.", "Toggle the Display flag on the Geometry COMP (blue flag in header) to show/hide it in renders without changing Render TOP parameters.", "The Geometry COMP Transform page (Translate, Rotate, Scale) positions the object in world space. Animate these with CHOP expressions.", "Enable instancing (Instance page, Instance On = 1) to render millions of copies of the geometry driven by CHOP channels (tx, ty, tz per instance).", "Assign a Phong MAT or PBR MAT via the Material parameter for physically-based shading.", "Use a Script CHOP to generate instance transforms procedurally: Fibonacci sphere, grid layout, random scatter.", "Level-of-Detail: use the LOD SOP inside the Geometry COMP to reduce triangle count at distance.", "Multiple SOPs can feed into a Geometry COMP — connect them into a Merge SOP first.", "Set the Render flag (render icon in header) to Off to exclude from all renders while keeping the Display flag on.", "Use Object CHOP or Parameter CHOP to read back the Geometry COMP's world-space transform from other operators." ], "warnings": [ "The Geometry COMP is referenced by path in Render TOP parameters — it is NOT wire-connected to Render TOP.", "Without a Material assigned the geometry renders with a flat default material. Always assign a MAT for correct shading.", "Instancing requires that the instance CHOP channels have exactly the right names (tx, ty, tz, rx, ry, rz, sx, sy, sz, or custom attribute names matching your MAT).", "High polygon-count SOPs inside a Geometry COMP will increase CPU-to-GPU upload time. Use Poly Reduce SOP or LOD SOP for heavy meshes.", "The Geometry COMP's internal coordinate system is its own object space. Translate/Rotate/Scale on the COMP move the whole object in world space." ], "parameters": [ { "id": null, "name": "Translate", "label": "Translate", "group": "Transform", "page": "Transform", "type": "float", "dataType": "float", "style": "XYZ", "defaultValue": [0, 0, 0], "description": "World-space translation of the geometry object. X=right, Y=up, Z=towards camera (OpenGL convention).", "tooltip": "Position in 3D world space.", "commonExpressions": [ "op('null1')['tx']", "sin(absTime.seconds) * 2" ], "isReadOnly": false, "isAnimatable": true, "order": 0, "isValid": true }, { "id": null, "name": "Rotate", "label": "Rotate", "group": "Transform", "page": "Transform", "type": "float", "dataType": "float", "style": "XYZ", "defaultValue": [0, 0, 0], "description": "Rotation in degrees around X, Y, Z axes. Applied in the order defined by Transform Order parameter.", "tooltip": "Rotation in degrees.", "commonExpressions": ["absTime.seconds * 30", "op('lfo1')['chan1'] * 360"], "isReadOnly": false, "isAnimatable": true, "order": 1, "isValid": true }, { "id": null, "name": "Scale", "label": "Scale", "group": "Transform", "page": "Transform", "type": "float", "dataType": "float", "style": "XYZ", "defaultValue": [1, 1, 1], "description": "Scale multiplier for each axis. Use uniform scale (all three equal) to avoid shearing.", "isReadOnly": false, "isAnimatable": true, "order": 2, "isValid": true }, { "id": null, "name": "Material", "label": "Material", "group": "Render", "page": "Render", "type": "string", "dataType": "string", "style": "OP", "defaultValue": "", "description": "Path to the MAT operator that defines the surface appearance (shader, textures, lighting response). Accepts Phong MAT, PBR MAT, GLSL MAT, etc.", "tooltip": "Path to MAT operator", "examples": ["phong1", "pbr1", "/project1/materials/metallic"], "isReadOnly": false, "isAnimatable": false, "order": 3, "isValid": true }, { "id": null, "name": "Instance", "label": "Instance On", "group": "Instance", "page": "Instance", "type": "int", "dataType": "int", "style": "Toggle", "defaultValue": 0, "description": "Enables GPU instancing. When On, the geometry is drawn multiple times (once per instance) using transform data from CHOP channels or Table DAT rows.", "isReadOnly": false, "isAnimatable": false, "order": 4, "isValid": true }, { "id": null, "name": "Instance CHOP", "label": "Instance CHOP", "group": "Instance", "page": "Instance", "type": "string", "dataType": "string", "style": "OP", "defaultValue": "", "description": "Path to a CHOP that provides per-instance transform data. Channel names tx, ty, tz, rx, ry, rz, sx, sy, sz are used automatically. Number of samples = number of instances.", "examples": ["null_instances", "script1"], "isReadOnly": false, "isAnimatable": false, "order": 5, "isValid": true } ], "parameterGroups": { "Transform": ["Translate", "Rotate", "Scale", "Transform Order", "Pivot"], "Render": ["Material", "Cull Face", "Depth Test"], "Instance": ["Instance On", "Instance CHOP", "Instance Count"] }, "codeExamples": [], "pythonExamples": [ { "title": "Animate Geometry COMP transform from Python", "description": "Drive position and rotation from an Execute DAT.", "code": "import math\n\ndef onFrameStart(frame):\n t = absTime.seconds\n geo = op('geo1')\n\n # Circular orbit\n radius = 3\n geo.par.tx = math.sin(t * 0.5) * radius\n geo.par.tz = math.cos(t * 0.5) * radius\n\n # Continuous Y rotation\n geo.par.ry = (t * 45) % 360 # 45 degrees per second" }, { "title": "GPU instancing with procedural transforms", "description": "Use a Script CHOP to generate instance positions in a Fibonacci sphere pattern.", "code": "# In a Script CHOP — generates N instances on a sphere surface\nimport numpy as np\n\nN = 500 # number of instances\n\ndef cook(scriptOp):\n scriptOp.clear()\n tx = scriptOp.appendChan('tx')\n ty = scriptOp.appendChan('ty')\n tz = scriptOp.appendChan('tz')\n tx.setSize(N)\n ty.setSize(N)\n tz.setSize(N)\n\n golden = (1 + np.sqrt(5)) / 2\n indices = np.arange(N)\n theta = np.arccos(1 - 2 * (indices + 0.5) / N)\n phi = 2 * np.pi * indices / golden\n r = 5 # sphere radius\n\n for i in range(N):\n tx[i] = r * np.sin(theta[i]) * np.cos(phi[i])\n ty[i] = r * np.cos(theta[i])\n tz[i] = r * np.sin(theta[i]) * np.sin(phi[i])\n\n# Geometry COMP: Instance On = 1, Instance CHOP = 'script1'" }, { "title": "Assign material dynamically", "description": "Switch between materials based on a condition.", "code": "MATERIALS = {'metal': 'pbr_metal', 'glass': 'pbr_glass', 'emissive': 'phong_glow'}\n\ndef setMaterial(geoName, materialKey):\n mat = MATERIALS.get(materialKey)\n if mat:\n op(geoName).par.material = mat\n print(f'[Geo] {geoName} material -> {mat}')\n\n# Switch to emissive on beat\nsetMaterial('geo1', 'emissive')" } ], "expressions": [ "op('geo1').par.tx = sin(absTime.seconds) * 2", "op('geo1').par.ry = absTime.seconds * 30", "op('geo1').par.material = 'phong1'", "op('geo1').display = True" ], "commonInputs": [ { "op": "Box SOP", "reason": "Simple box geometry to render" }, { "op": "Sphere SOP", "reason": "Sphere geometry" }, { "op": "Grid SOP", "reason": "Plane / terrain geometry" }, { "op": "Text SOP", "reason": "3D extruded text" }, { "op": "Script SOP", "reason": "Procedurally generated geometry" }, { "op": "Noise SOP", "reason": "Deformed geometry" }, { "op": "Merge SOP", "reason": "Combined multiple SOP sources" } ], "commonOutputs": [], "relatedOperators": [ "Render TOP", "Camera COMP", "Light COMP", "Phong MAT", "PBR MAT", "GLSL MAT", "Box SOP", "Sphere SOP", "Grid SOP", "Noise SOP", "Script SOP", "Object CHOP", "Render Pick CHOP" ], "workflowPatterns": ["3d-render-pipeline", "generative-art", "live-performance"], "keywords": [ "geometry", "3d", "mesh", "polygon", "render", "instancing", "material", "transform", "position", "rotation", "scale", "sop", "gpu", "object", "scene", "world space", "display", "flag", "lod" ], "tags": ["COMP", "3D", "Geometry COMP", "rendering", "instancing", "sop"], "searchWeight": 2, "contentHash": "", "processingDate": "2026-02-21T00:00:00.000Z", "processingVersion": "2.10.0", "isValid": true, "validationErrors": [] }