3D建模

Blender动画节点插件开发文档-输出

ygtu

Mar 25, 2023 • 4 min read

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在最后一部分中，我们创建了第一个复制从一个对象到另一个对象的位置，并应用自定义偏移。这是最后一章的结果：

import bpy
from animation_nodes.base_types import AnimationNode

class CopyLocationWithOffsetNode(bpy.types.Node, AnimationNode):
    bl_idname = "an_CopyLocationWithOffsetNode"
    bl_label = "Copy Location with Offset"

    def create(self):
        self.newInput("Object", "Source", "source")
        self.newInput("Object", "Target", "target")
        self.newInput("Vector", "Offset", "offset")

    def execute(self, source, target, offset):
        if source is None or target is None:
            return

        target.location = source.location + offset

在这一部分中，我们要扩展此节点。首先我们想改变节点，以便它输出目标对象的新位置。因此我们需要在函数中写一个新行，如下所示：create(self)

def create(self):
    self.newInput("Object", "Source", "source")
    self.newInput("Object", "Target", "target")
    self.newInput("Vector", "Offset", "offset")
    self.newOutput("Vector", "Target Location", "targetLocation")

很简单，对吧？现在我必须调整方法这样它实际上返回了一个向量。目前它只是一直返回。现在始终返回一个向量非常重要。所有其他可能使用此值取决于这是一个向量，不要显式检查类型。这意味着如果节点。新方法可能如下所示：executeNoneexecute

def execute(self, source, target, offset):
    if source is None or target is None:
        return Vector((0, 0, 0)) # this is the default value

    target.location = source.location + offset
    return target.location

如您所见，我们创建了此对象。每单个向量应为此类型。为了做到这一点代码工作我们需要导入文件顶部的类型：。Vector((0, 0, 0))from mathutils import Vector

该节点现在再次完全正常运行。

import bpy
from mathutils import Vector
from animation_nodes.base_types import AnimationNode

class CopyLocationWithOffsetNode(bpy.types.Node, AnimationNode):
    bl_idname = "an_CopyLocationWithOffsetNode"
    bl_label = "Copy Location with Offset"

    def create(self):
        self.newInput("Object", "Source", "source")
        self.newInput("Object", "Target", "target")
        self.newInput("Vector", "Offset", "offset")
        self.newOutput("Vector", "Target Location", "targetLocation")

    def execute(self, source, target, offset):
        if source is None or target is None:
            return Vector((0, 0, 0))

        target.location = source.location + offset
        return target.location

import bpy
from mathutils import Vector
from animation_nodes.base_types import AnimationNode

class CopyLocationWithOffsetNode(bpy.types.Node, AnimationNode):
    bl_idname = "an_CopyLocationWithOffsetNode"
    bl_label = "Copy Location with Offset"

    def create(self):
        self.newInput("Object", "Source", "source")
        self.newInput("Object", "Target", "target")
        self.newInput("Vector", "Offset", "offset")
        self.newOutput("Vector", "Source Location", "sourceLocation")
        self.newOutput("Vector", "Target Location", "targetLocation")

    def execute(self, source, target, offset):
        if source is None or target is None:
            return Vector((0, 0, 0)), Vector((0, 0, 0))

        target.location = source.location + offset
        return source.location, target.location

现在我们要更改节点，以便它不仅输出位置目标对象以及源对象的位置。我想在这一点上，很明显我们必须如何改变方法。create(self)

def create(self):
    self.newInput("Object", "Source", "source")
    self.newInput("Object", "Target", "target")
    self.newInput("Vector", "Offset", "offset")
    self.newOutput("Vector", "Source Location", "sourceLocation")
    self.newOutput("Vector", "Target Location", "targetLocation")

Python具有出色的功能，您可以轻松返回多个方法中的对象。为了返回两个对象，我们将完全使用特征。关于这一点，您必须了解两件主要事情：

返回对象的数量始终必须与输出套接字。
返回对象的顺序必须对应于输出套接字。

为了满足这两个要求，该方法的代码可以看起来像这样：execute

def execute(self, source, target, offset):
    if source is None or target is None:
        return Vector((0, 0, 0)), Vector((0, 0, 0)) # we need two defaults as well

    target.location = source.location + offset
    return source.location, target.location

同样，我们的节点功能齐全，所以我们结束了这一切 .part。

import bpy
from mathutils import Vector
from animation_nodes.base_types import AnimationNode

class CopyLocationWithOffsetNode(bpy.types.Node, AnimationNode):
    bl_idname = "an_CopyLocationWithOffsetNode"
    bl_label = "Copy Location with Offset"

    def create(self):
        self.newInput("Object", "Source", "source")
        self.newInput("Object", "Target", "target")
        self.newInput("Vector", "Offset", "offset")
        self.newOutput("Vector", "Source Location", "sourceLocation")
        self.newOutput("Vector", "Target Location", "targetLocation")

    def execute(self, source, target, offset):
        if source is None or target is None:
            return Vector((0, 0, 0)), Vector((0, 0, 0))

        target.location = source.location + offset
        return source.location, target.location

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