P09：PRINCIPLED BSDF 设置

ID: P09 | 类别: Materials PBR | 提示词: ⭐ | Tags: #materials #pbr #principled-bshf #shader-nodes

---

🎯 目标

创建并配置带完整 PBR 贴图集的 Principled BSDF 材质

---

📝 提示词

创建 "[MAT_NAME]" 材质，类型 Principled BSDF:
Base Color: [R, G, B] 或 hex #RRGGBB
Roughness: [0.0-1.0]
Metallic: [0.0-1.0]
[可选] Transmission, IOR, Clearcoat, Sheen, Emission
指定给对象 "[OBJECT_NAME]"

---

🔧 MCP: set_material（基础）

{
  "type": "set_material",
  "params": {
    "object_name": "Cube",
    "material_name": "Mat_Red",
    "color": [1.0, 0.0, 0.0, 1.0]
  }
}

---

🔧 MCP: execute_blender_code（完整 PBR）

import bpy
from pathlib import Path

def create_pbr_material(name, maps_dict, obj_name=None):
    """
    maps_dict keys: 'base_color', 'roughness', 'metallic', 'normal', 'height', 'ao', 'emission'
    values: 文件路径或颜色元组 (R,G,B,A)
    """
    mat = bpy.data.materials.new(name)
    mat.use_nodes = True
    nodes = mat.node_tree.nodes
    links = mat.node_tree.links
    nodes.clear()

    # Principled BSDF
    principled = nodes.new('ShaderNodeBsdfPrincipled')
    principled.location = (0, 0)

    # Material Output
    output = nodes.new('ShaderNodeOutputMaterial')
    output.location = (400, 0)
    links.new(principled.outputs['BSDF'], output.inputs['Surface'])

    # Displacement
    disp = nodes.new('ShaderNodeDisplacement')
    disp.location = (200, -200)
    links.new(disp.outputs['Displacement'], output.inputs['Displacement'])
    mat.displacement_method = 'BOTH'

    # Texture Coordinate + Mapping
    tex_coord = nodes.new('ShaderNodeTexCoord')
    tex_coord.location = (-600, 0)
    mapping = nodes.new('ShaderNodeMapping')
    mapping.location = (-400, 0)
    links.new(tex_coord.outputs['UV'], mapping.inputs['Vector'])

    def add_texture(key, input_name, colorspace='sRGB', use_normal_map=False, use_disp=False):
        if key not in maps_dict:
            return
        val = maps_dict[key]

        if isinstance(val, (tuple, list)):  # 颜色
            principled.inputs[input_name].default_value = val + (1.0,) if len(val)==3 else val
            return

        # 图像文件
        tex = nodes.new('ShaderNodeTexImage')
        tex.image = bpy.data.images.load(str(val))
        tex.image.colorspace_settings.name = colorspace
        tex.location = (-200, 0)
        links.new(mapping.outputs['Vector'], tex.inputs['Vector'])

        if use_normal_map:
            nmap = nodes.new('ShaderNodeNormalMap')
            nmap.location = (0, -100)
            links.new(tex.outputs['Color'], nmap.inputs['Color'])
            links.new(nmap.outputs['Normal'], principled.inputs[input_name])
        elif use_disp:
            links.new(tex.outputs['Color'], disp.inputs['Height'])
        else:
            links.new(tex.outputs['Color'], principled.inputs[input_name])

    # 连接贴图
    add_texture('base_color', 'Base Color', 'sRGB')
    add_texture('roughness', 'Roughness', 'Non-Color')
    add_texture('metallic', 'Metallic', 'Non-Color')
    add_texture('normal', 'Normal', 'Non-Color', use_normal_map=True)
    add_texture('height', 'Height', 'Non-Color', use_disp=True)
    add_texture('emission', 'Emission Color', 'sRGB')

    # AO -> 与 Base Color 混合
    if 'ao' in maps_dict:
        ao_tex = nodes.new('ShaderNodeTexImage')
        ao_tex.image = bpy.data.images.load(str(maps_dict['ao']))
        ao_tex.image.colorspace_settings.name = 'Non-Color'
        ao_tex.location = (-200, 200)
        links.new(mapping.outputs['Vector'], ao_tex.inputs['Vector'])

        mix = nodes.new('ShaderNodeMixRGB')
        mix.blend_type = 'MULTIPLY'
        mix.location = (0, 100)
        # 通过 Mix 重连 Base Color
        if principled.inputs['Base Color'].links:
            from_node = principled.inputs['Base Color'].links[0].from_node
            from_socket = principled.inputs['Base Color'].links[0].from_socket
            links.new(from_socket, mix.inputs[1])
        links.new(ao_tex.outputs['Color'], mix.inputs[2])
        links.new(mix.outputs['Color'], principled.inputs['Base Color'])

    # 指定给对象
    if obj_name:
        obj = bpy.data.objects.get(obj_name)
        if obj:
            if obj.data.materials:
                obj.data.materials[0] = mat
            else:
                obj.data.materials.append(mat)

    return mat

# === 使用示例 ===

# 1. 纯色
create_pbr_material("Mat_Red", {
    'base_color': (1.0, 0.2, 0.2, 1.0),
    'roughness': 0.5,
    'metallic': 0.0
}, "Cube")

# 2. 金色
create_pbr_material("Mat_Gold", {
    'base_color': (1.0, 0.843, 0.0, 1.0),
    'roughness': 0.1,
    'metallic': 1.0
}, "Ring")

# 3. 玻璃
create_pbr_material("Mat_Glass", {
    'base_color': (1.0, 1.0, 1.0, 1.0),
    'roughness': 0.0,
    'transmission': 1.0,  # 需要时加到函数中
    'ior': 1.45
}, "Glass_Obj")

# 4. 来自文件的完整 PBR
create_pbr_material("Mat_Brick", {
    'base_color': Path("//textures/brick_basecolor.png"),
    'roughness': Path("//textures/brick_roughness.png"),
    'normal': Path("//textures/brick_normal.png"),
    'height': Path("//textures/brick_height.png"),
    'ao': Path("//textures/brick_ao.png"),
}, "Wall")

---

📊 PBR 参数速查

材质	Base Color	Roughness	Metallic	Transmission	IOR	Clearcoat
塑料	颜色	0.3-0.5	0.0	0.0	1.5	0.0
金属（抛光）	金属色	0.05-0.15	1.0	0.0	—	0.0
金属（锈蚀/哑光）	金属色	0.6-0.9	1.0	0.0	—	0.0
玻璃	白色	0.0	0.0	1.0	1.45-1.5	0.0
水	浅蓝	0.05	0.0	1.0	1.33	0.0
皮肤	肤色	0.6-0.8	0.0	0.0	1.5	0.1-0.3
布料	布色	0.8-1.0	0.0	0.0	1.5	0.0
陶瓷	颜色	0.1-0.3	0.0	0.0	1.5	0.2-0.5
石头/混凝土	灰/米	0.7-1.0	0.0	0.0	1.5	0.0
木材	木色	0.6-0.9	0.0	0.0	1.5	0.0

---

🎨 特殊效果

Emission（发光）

principled.inputs['Emission Color'].default_value = (1.0, 0.8, 0.2, 1.0)  # 暖光
principled.inputs['Emission Strength'].default_value = 5.0  # 强度

Clearcoat（清漆/陶瓷）

principled.inputs['Coat Weight'].default_value = 1.0
principled.inputs['Coat Roughness'].default_value = 0.03

Sheen（布料/丝绒）

principled.inputs['Sheen Weight'].default_value = 0.5
principled.inputs['Sheen Roughness'].default_value = 0.3
principled.inputs['Sheen Tint'].default_value = 0.5

Subsurface（皮肤、蜡、大理石）

principled.inputs['Subsurface Weight'].default_value = 0.3
principled.inputs['Subsurface Radius'].default_value = (1.0, 0.2, 0.1)  # RGB 穿透半径
principled.inputs['Subsurface Color'].default_value = (1.0, 0.3, 0.1, 1.0)

Anisotropic（拉丝表面）

principled.inputs['Anisotropic'].default_value = 0.8
principled.inputs['Anisotropic Rotation'].default_value = 0.25  # 90°
# 需要 Tangent 输入（UV 或 Geometry > Tangent）

---

🔗 СВЯЗИ

• 案例: Case 01: ArchViz, Case 03: Product Viz
• 工作流: WF 03: Texture Pipeline
• 提示词: P10 Node Groups, P11 Procedural Textures
• MCP 工具: set_material（基础），execute_blender_code（完整）
• 下一个: P10: Node Group Creation