I want to make a node group that outputs a polygon with a customizable size and side count.
I'm using arctan2 to make a setup that I figured would allow for a customizable side count.
If I add these nodes and mess around with the values I can get something closer, but it ever only results in rounded star shapes.
I can't seem to get a regular polygon.
Method result:
Changing side count:
Changing outer radius:
Nodes:
Explanation:
What we are doing here is verifying the difference between the texture coordinates and a vertical line, but we need to cycle the angle θ of that coordinate when it points past the polygon segment lenght in the line (sometimes i'm bad at explaining so look this):
https://www.desmos.com/calculator/tqy07xvs14
With this method, instead of using a less than 1 node, you can also use ColorRamps:
import bpy, math
select and del all object
bpy.ops.object.mode_set(mode='OBJECT')
bpy.ops.object.select_all(action = "SELECT")
bpy.ops.object.delete(use_global=True, confirm=False)
add plane
bpy.ops.mesh.primitive_plane_add(size=2, enter_editmode=False, align='WORLD', location=(0, 0, 0), scale=(1, 1, 1))
oj = bpy.context.object
mat = bpy.data.materials.new(name="Material")
oj.data.materials.append(mat)
mat.use_nodes = True
tree = mat.node_tree
nodes = tree.nodes
l = tree.links
coor = nodes.new("ShaderNodeTexCoord")
coor.location.x += -300
coor.location.y += -1200
def new_mapp(dx=0, dy=0):
node = nodes.new("ShaderNodeMapping")
node.location.x += dx
node.location.y += dy
node.vector_type = "TEXTURE"
return node
def new_rang(dx=0, dy=0):
node = nodes.new("ShaderNodeMapRange")
node.location.x += dx
node.location.y += dy
node.inputs["From Max"].default_value = 0.001
return node
def new_invert(dx=0, dy=0):
node = nodes.new("ShaderNodeInvert")
node.location.x += dx
node.location.y += dy
return node
def new_mix(dx=0, dy=0):
node = nodes.new("ShaderNodeMixRGB")
node.location.x += dx
node.location.y += dy
node.blend_type = 'MULTIPLY'
node.inputs[0].default_value = 1
return node
mapp1 = new_mapp()
mapp1.inputs["Location"].default_value[1] = 0.5
mapp1.inputs["Rotation"].default_value[2] = math.radians(279)
rang1 = new_rang(200)
l.new(coor.outputs["UV"], mapp1.inputs["Vector"])
l.new(mapp1.outputs["Vector"], rang1.inputs[0])
mapp2 = new_mapp(0, -600)
mapp2.inputs["Location"].default_value[1] = 0.5
mapp2.inputs["Rotation"].default_value[2] = math.radians(-369)
rang2 = new_rang(200, -600)
l.new(coor.outputs["UV"], mapp2.inputs["Vector"])
l.new(mapp2.outputs["Vector"], rang2.inputs[0])
mapp3 = new_mapp(0, -1200)
mapp3.inputs["Location"].default_value[1] = -0.08778525229247
mapp3.inputs["Rotation"].default_value[2] = math.radians(-297)
rang3 = new_rang(200, -1200)
l.new(coor.outputs["UV"], mapp3.inputs["Vector"])
l.new(mapp3.outputs["Vector"], rang3.inputs[0])
mapp4 = new_mapp(0, -1800)
mapp4.inputs["Location"].default_value[1] = 1 +0.08778525229247
mapp4.inputs["Rotation"].default_value[2] = math.radians(-153)
rang4 = new_rang(200, -1800)
l.new(coor.outputs["UV"], mapp4.inputs["Vector"])
l.new(mapp4.outputs["Vector"], rang4.inputs[0])
mapp5 = new_mapp(0, -2400)
mapp5.inputs["Location"].default_value[0] = 1 -0.09549150281253
mapp5.inputs["Rotation"].default_value[2] = math.radians(-225)
rang5 = new_rang(200, -2400)
l.new(coor.outputs["UV"], mapp5.inputs["Vector"])
l.new(mapp5.outputs["Vector"], rang5.inputs[0])
mix1 = new_mix(500, -200)
mix2 = new_mix(700, -800)
mix3 = new_mix(900, -1400)
mix4 = new_mix(1100, -2000)
l.new(rang1.outputs["Result"], mix1.inputs["Color1"])
l.new(rang2.outputs["Result"], mix1.inputs["Color2"])
l.new(mix1.outputs["Color"], mix2.inputs["Color1"])
l.new(rang3.outputs["Result"], mix2.inputs["Color2"])
l.new(mix2.outputs["Color"], mix3.inputs["Color1"])
l.new(rang4.outputs["Result"], mix3.inputs["Color2"])
l.new(mix3.outputs["Color"], mix4.inputs["Color1"])
l.new(rang5.outputs["Result"], mix4.inputs["Color2"])
bsdf = nodes["Principled BSDF"]
bsdf.location.x += 1300
bsdf.location.y += -1500
outp = nodes["Material Output"]
outp.location.x += 1300
outp.location.y += -1500
l.new(mix4.outputs["Color"], bsdf.inputs["Alpha"])
Here's my take:
Alternative:
The idea is the same as in Hulifier's answer, rather than calculating how distance to edge changes with angle, just rotate the coordinate system so all directions point to the left. Since radial gradient starts in the middle of "the left", either use the first solution to rotate the first half of the 1st side angle to the bottom-left, and the 2nd half of the last side angle to the top-left, or use the second solution to first rotate the coordinate system so the radial gradient actually starts at the beginning of "the left"... (preview the output of the Snap node to see that better).
