# Blender Geonodes > > - **Type:** Skill - **Install:** `agentstack add skill-max-786-claude-3d-harness-blender-geonodes` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [MAX-786](https://agentstack.voostack.com/s/max-786) - **Installs:** 0 - **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [MAX-786](https://github.com/MAX-786) - **Source:** https://github.com/MAX-786/claude-3d-harness/tree/main/library/gaius/blender-geonodes ## Install ```sh agentstack add skill-max-786-claude-3d-harness-blender-geonodes ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Skill: Blender Geometry Nodes (Procedurale) Sei un esperto di Geometry Nodes in Blender via Python. Costruisci node tree parametrici e non-distruttivi da codice. --- ## Connessione — MCP (predefinito) ```python mcp__Blender__execute_blender_code(code=""" import bpy # ... codice ... result = {"ok": True} """) mcp__Blender__get_screenshot_of_window_as_image() mcp__Blender__render_viewport_to_path(output_path="/gn.png") ``` --- ## IL PRINCIPIO — GeoNodes vs Python bmesh | | bmesh (blender-arch/procedural) | Geometry Nodes | |-|----------------------------------|----------------| | Distruttivo | Sì — modifica la mesh | No — modifier on top | | Parametrico | No (dopo apply) | Sì — sliders sempre | | Istanziazione | Slow (N oggetti separati) | Fast (GPU instancing) | | Animabile | Solo con driver | Sì — natively | | Complessità API | Media | Alta (node graph) | **Usa GeoNodes quando:** - Il risultato deve rimanere modificabile (number of instances, density...) - Stai istanziando molti oggetti (> 50) - Vuoi animare i parametri - La forma deriva da una curva o da una superficie esistente --- ## SETUP BASE — Modifier + Node Group ```python import bpy def create_gn_modifier(obj, name="GeoNodes"): """ Crea un modifier Geometry Nodes su obj e un node group vuoto. Ritorna (modifier, node_group, nodes, links). Blender 4.x/5.x: usa ng.interface.new_socket() per I/O, NON ng.inputs.new() / ng.outputs.new() (deprecati in 4.0). """ mod = obj.modifiers.new(name, 'NODES') ng = bpy.data.node_groups.new(name + "_Tree", 'GeometryNodeTree') mod.node_group = ng # Interfaccia I/O — ORDINE IMPORTANTE: OUTPUT prima di INPUT if hasattr(ng, 'interface'): ng.interface.new_socket("Geometry", in_out="OUTPUT", socket_type="NodeSocketGeometry") ng.interface.new_socket("Geometry", in_out="INPUT", socket_type="NodeSocketGeometry") # Nodi Group Input e Output (terminali del grafo) in_node = ng.nodes.new("NodeGroupInput") out_node = ng.nodes.new("NodeGroupOutput") in_node.location = (-400, 0) out_node.location = ( 400, 0) # Pass-through di default (geometry → output invariata) ng.links.new(in_node.outputs[0], out_node.inputs[0]) return mod, ng, ng.nodes, ng.links # Uso base: # bpy.ops.mesh.primitive_plane_add(size=2) # plane = bpy.context.active_object # mod, ng, nodes, links = create_gn_modifier(plane, "MyGeoNodes") ``` --- ## HELPER FUNCTIONS ```python def add_node(nodes, bl_idname, location=(0,0), **props): """ Aggiunge un nodo e imposta proprietà. props: coppie nome=valore per inputs o attributi del nodo. Esempi: add_node(nodes, 'GeometryNodeMeshPrimitiveSphere', location=(200, 0), inputs={'Radius': 0.05}) add_node(nodes, 'FunctionNodeRandomValue', location=(0, -200), data_type='FLOAT_VECTOR') """ n = nodes.new(bl_idname) n.location = location for k, v in props.items(): if k == 'inputs': for input_name, val in v.items(): if input_name in n.inputs: n.inputs[input_name].default_value = val else: setattr(n, k, v) return n def link(links, from_node, from_socket, to_node, to_socket): """ Collega due nodi. Accetta indici interi o nomi stringa per i socket. Esempi: link(links, dist, "Points", inst, "Points") link(links, math, 0, out_node, 0) # per indice """ if isinstance(from_socket, int): fs = from_node.outputs[from_socket] else: fs = from_node.outputs[from_socket] if isinstance(to_socket, int): ts = to_node.inputs[to_socket] else: ts = to_node.inputs[to_socket] return links.new(fs, ts) def add_group_input(ng, name, socket_type, default=None, min_val=None, max_val=None): """ Aggiunge un Group Input parametrico (slider visibile nel modifier). socket_type: 'NodeSocketFloat' | 'NodeSocketInt' | 'NodeSocketVector' 'NodeSocketBool' | 'NodeSocketObject' | 'NodeSocketMaterial' 'NodeSocketGeometry' | 'NodeSocketColor' Esempio: add_group_input(ng, "Density", "NodeSocketFloat", default=500, min_val=0, max_val=5000) add_group_input(ng, "Scale", "NodeSocketFloat", default=1.0, min_val=0.01, max_val=5.0) add_group_input(ng, "Instance", "NodeSocketObject") add_group_input(ng, "Seed", "NodeSocketInt", default=0) Dopo averlo aggiunto, accedilo via in_node.outputs[name] nel grafo. Il valore è modificabile via modifier nel Properties panel. """ sock = ng.interface.new_socket(name, in_out="INPUT", socket_type=socket_type) if default is not None: try: sock.default_value = default except: pass if min_val is not None: try: sock.min_value = min_val except: pass if max_val is not None: try: sock.max_value = max_val except: pass return sock ``` --- ## PATTERN 1 — Scatter istanze su superficie Il pattern più comune: distribuisce copie di un oggetto su una mesh. Usato per: sprinkles su donut, erba su terreno, pietre su pavimento, foglie su rami, chiodi su tavola, bottoni su tessuto. ```python def scatter_on_surface(host_obj, instance_obj, density=500.0, random_rotation=True, align_to_normal=True, scale_min=0.8, scale_max=1.2, seed=0, name="Scatter"): """ Scatter di instance_obj sulla superficie di host_obj. density : istanze per m² [BU²] random_rotation: ruota casualmente ogni istanza sull'asse normale align_to_normal: orienta le istanze lungo la normale della superficie scale_min/max : range scala casuale (1.0 = nessuna variazione) seed : seed casuale — cambia per layout diverso Pipeline: Geometry → Distribute Points on Faces → Instance on Points → Rotate → Scale → Realize → Output Esempi: # Sprinkles su donut scatter_on_surface(icing, sprinkle, density=3000, seed=42) # Erba su terreno scatter_on_surface(terrain, grass_blade, density=200, scale_min=0.7, scale_max=1.5, seed=7) # Pietre su pavimento scatter_on_surface(floor, rock, density=50, random_rotation=True, align_to_normal=False) """ mod, ng, nds, lks = create_gn_modifier(host_obj, name) # Rimuovi il link pass-through di default for l in list(lks): lks.remove(l) in_nd = next(n for n in nds if n.bl_idname == "NodeGroupInput") out_nd = next(n for n in nds if n.bl_idname == "NodeGroupOutput") # Group Input parametrici add_group_input(ng, "Density", "NodeSocketFloat", default=density, min_val=0, max_val=10000) add_group_input(ng, "Seed", "NodeSocketInt", default=seed) # Distribute Points on Faces dist = add_node(nds, "GeometryNodeDistributePointsOnFaces", location=(0, 0), inputs={"Density": density}) dist.distribute_method = "RANDOM" # Object Info (geometria dell'istanza) obj_info = add_node(nds, "GeometryNodeObjectInfo", location=(0, -200)) obj_info.inputs["Object"].default_value = instance_obj obj_info.transform_space = 'ORIGINAL' # Instance on Points inst = add_node(nds, "GeometryNodeInstanceOnPoints", location=(300, 0)) cur_x = 500 last_out = ("Instances", inst) if align_to_normal: lks.new(dist.outputs["Normal"], inst.inputs["Rotation"]) # Rotazione casuale if random_rotation: rand_rot = add_node(nds, "FunctionNodeRandomValue", location=(0, -400)) rand_rot.data_type = "FLOAT_VECTOR" rand_rot.inputs["Min"].default_value = (0, 0, 0) rand_rot.inputs["Max"].default_value = (6.2832, 6.2832, 6.2832) rot = add_node(nds, "GeometryNodeRotateInstances", location=(cur_x, 0)) lks.new(last_out[1].outputs[last_out[0]], rot.inputs["Instances"]) lks.new(rand_rot.outputs[0], rot.inputs["Rotation"]) last_out = ("Instances", rot) cur_x += 200 # Scala casuale if scale_min != 1.0 or scale_max != 1.0: rand_sc = add_node(nds, "FunctionNodeRandomValue", location=(cur_x - 200, -300)) rand_sc.data_type = "FLOAT" rand_sc.inputs[2].default_value = scale_min # Min float rand_sc.inputs[3].default_value = scale_max # Max float sc_inst = add_node(nds, "GeometryNodeScaleInstances", location=(cur_x, 0)) lks.new(last_out[1].outputs[last_out[0]], sc_inst.inputs["Instances"]) lks.new(rand_sc.outputs[1], sc_inst.inputs["Scale"]) last_out = ("Instances", sc_inst) cur_x += 200 # Realize Instances (converte in mesh reale) realize = add_node(nds, "GeometryNodeRealizeInstances", location=(cur_x, 0)) # Join Geometry (mantiene la superficie host + le istanze) join = add_node(nds, "GeometryNodeJoinGeometry", location=(cur_x + 200, 0)) # Collega tutto lks.new(in_nd.outputs[0], dist.inputs["Mesh"]) lks.new(in_nd.outputs["Density"], dist.inputs["Density"]) lks.new(dist.outputs["Points"], inst.inputs["Points"]) lks.new(obj_info.outputs["Geometry"], inst.inputs["Instance"]) lks.new(last_out[1].outputs[last_out[0]], realize.inputs["Geometry"]) lks.new(in_nd.outputs[0], join.inputs["Geometry"]) lks.new(realize.outputs["Geometry"], join.inputs["Geometry"]) lks.new(join.outputs["Geometry"], out_nd.inputs[0]) return mod, ng ``` --- ## PATTERN 2 — Curve to Mesh (tubo da curva) Crea tubi, cavi, cornici, tubi idraulici da curve Bezier/NURBS. Parametrico: cambia il profilo o la curva e il tubo si aggiorna. ```python def curve_to_pipe(curve_obj, profile_radius=0.02, resolution=12, name="CurvePipe"): """ Genera un tubo circolare lungo una curva con Geometry Nodes. curve_obj : oggetto curva Bezier/NURBS/Poly profile_radius : raggio del tubo [BU] resolution : divisioni angolari della sezione circolare Pipeline: Curve Input → Curve to Mesh (con Circle profile) → Output Più flessibile di blender-arch pipe_along_points perché: - Il profilo può essere qualsiasi curva (ovale, quadrato...) - Tutto è non-distruttivo e animabile - La risoluzione è regolabile dopo creazione Esempi: # Tubo idraulico curve_to_pipe(pipe_curve, profile_radius=0.015) # Cavo elettrico (più sottile) curve_to_pipe(cable_curve, profile_radius=0.004, resolution=8) # Cornice architettonica (profilo rettangolare → usa curve_to_profile) curve_to_pipe(cornice_curve, profile_radius=0.05) """ mod, ng, nds, lks = create_gn_modifier(curve_obj, name) for l in list(lks): lks.remove(l) in_nd = next(n for n in nds if n.bl_idname == "NodeGroupInput") out_nd = next(n for n in nds if n.bl_idname == "NodeGroupOutput") # Group Input per raggio (parametrico) add_group_input(ng, "Radius", "NodeSocketFloat", default=profile_radius, min_val=0.001, max_val=1.0) # Curve Circle (profilo circolare) circle = add_node(nds, "GeometryNodeCurvePrimitiveCircle", location=(0, -200), inputs={"Resolution": resolution, "Radius": profile_radius}) circle.mode = 'RADIUS' # Curve to Mesh c2m = add_node(nds, "GeometryNodeCurveToMesh", location=(300, 0)) c2m.inputs["Fill Caps"].default_value = True # Set Shade Smooth smooth = add_node(nds, "GeometryNodeSetShadeSmooth", location=(500, 0)) smooth.inputs["Shade Smooth"].default_value = True lks.new(in_nd.outputs[0], c2m.inputs["Curve"]) lks.new(in_nd.outputs["Radius"], circle.inputs["Radius"]) lks.new(circle.outputs["Curve"], c2m.inputs["Profile Curve"]) lks.new(c2m.outputs["Mesh"], smooth.inputs["Geometry"]) lks.new(smooth.outputs["Geometry"], out_nd.inputs[0]) return mod, ng def curve_to_profile(curve_obj, profile_curve_obj, name="CurveProfile"): """ Estrue un profilo personalizzato lungo una curva. profile_curve_obj: curva 2D che definisce la sezione (cornice, binario...) Esempio: # Crea profilo L (angolare) bpy.ops.curve.primitive_bezier_curve_add() profile = bpy.context.active_object # ... modifica i punti del profilo in Edit Mode ... curve_to_profile(rail_curve, profile) """ mod, ng, nds, lks = create_gn_modifier(curve_obj, name) for l in list(lks): lks.remove(l) in_nd = next(n for n in nds if n.bl_idname == "NodeGroupInput") out_nd = next(n for n in nds if n.bl_idname == "NodeGroupOutput") # Object Info per il profilo prof_info = add_node(nds, "GeometryNodeObjectInfo", location=(0, -200)) prof_info.inputs["Object"].default_value = profile_curve_obj # Object to Curve obj2curve = add_node(nds, "GeometryNodeObjectInfo", location=(0, -200)) c2m = add_node(nds, "GeometryNodeCurveToMesh", location=(300, 0)) c2m.inputs["Fill Caps"].default_value = True lks.new(in_nd.outputs[0], c2m.inputs["Curve"]) lks.new(prof_info.outputs["Geometry"], c2m.inputs["Profile Curve"]) lks.new(c2m.outputs["Mesh"], out_nd.inputs[0]) return mod, ng ``` --- ## PATTERN 3 — Deformazione noise (Set Position) Deforma una mesh in modo procedurale e non-distruttivo. Alternativa a blender-sculpt quando vuoi parametri animabili. ```python def noise_deform(obj, scale=5.0, strength=0.05, detail=6.0, direction='normal', seed=0, name="NoiseDeform"): """ Deformazione noise non-distruttiva via Geometry Nodes. scale : frequenza del noise (2=grosso, 8=medio, 20=fine) strength : intensità dello spostamento [BU] detail : ottave del noise (2=liscio, 8=rugoso) direction : 'normal' (lungo normali) | 'z' | 'xyz' (tutte le direzioni) A differenza di blender-sculpt, questo è completamente reversibile: basta disabilitare/rimuovere il modifier. Usi: terreno ondulato, superficie d'acqua, bandiera che sventola, superfici organiche parametriche, deformazione per animazione. """ mod, ng, nds, lks = create_gn_modifier(obj, name) for l in list(lks): lks.remove(l) in_nd = next(n for n in nds if n.bl_idname == "NodeGroupInput") out_nd = next(n for n in nds if n.bl_idname == "NodeGroupOutput") # Group Inputs parametrici add_group_input(ng, "Strength", "NodeSocketFloat", default=strength, min_val=0, max_val=1.0) add_group_input(ng, "Scale", "NodeSocketFloat", default=scale, min_val=0.1, max_val=50.0) # Position (coordinate vertici) pos = add_node(nds, "GeometryNodeInputPosition", location=(-400, -200)) # Normal (per direction='normal') if direction == 'normal': normal = add_node(nds, "GeometryNodeInputNormal", location=(-400, -400)) # Noise Texture noise = add_node(nds, "ShaderNodeTexNoise", location=(-200, 0)) noise.noise_dimensions = '3D' noise.inputs["Scale"].default_value = scale noise.inputs["Detail"].default_value = detail noise.inputs["Roughness"].default_value = 0.5 # Math: remap da [0,1] a [-1,1] remap = add_node(nds, "ShaderNodeMap … ## Source & license This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [MAX-786](https://github.com/MAX-786) - **Source:** [MAX-786/claude-3d-harness](https://github.com/MAX-786/claude-3d-harness) - **License:** MIT Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/skill-max-786-claude-3d-harness-blender-geonodes - Seller: https://agentstack.voostack.com/s/max-786 - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.