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Asked By | Gamemap |
I want to create a stage scene with fog and spotlights, but I can’t make the beam visible.
I would like to color the parts of the fog (Godot 4.0) that the beam goes through in the color of the spotlights (currently I only see the option to color the entire fog node).
If this is not possible, I would like to create a beam without the fog node.
I want to create something like this:
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Reply From: | cm |
I haven’t had much success with visible light in volumetric fog, but I recently wrote a quick script to fake it with a transparent cylinder. This is pretty crude, and may or may not work for you, but here’s my script which can be dropped directly onto a spotlight:
extends SpotLight3D
@export var length: float = 6.0
@export_range(0.0, 1.0, 0.01) var falloff: float = 1.0
@export_range(0.0, 1.0, 0.01) var opacity: float = 0.2
var _cone_mesh: MeshInstance3D = null
func _ready() -> void:
_cone_mesh = MeshInstance3D.new()
var cylinder = CylinderMesh.new()
cylinder.material = build_material()
_cone_mesh.mesh = cylinder
_cone_mesh.cast_shadow = false
add_child(_cone_mesh)
update_position()
update_cone()
func build_material() -> StandardMaterial3D:
var mat = StandardMaterial3D.new()
mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
mat.blend_mode = BaseMaterial3D.BLEND_MODE_ADD
mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
var grad = Gradient.new()
grad.set_color(0, Color(light_color, opacity))
grad.set_color(1, Color(light_color, 0.0))
var grad_tex = GradientTexture2D.new()
grad_tex.gradient = grad
grad_tex.fill_from = Vector2(0.0, 0.0)
grad_tex.fill_to = Vector2(0.0, 0.5 * falloff)
mat.albedo_texture = grad_tex
return mat
func update_position() -> void:
_cone_mesh.rotation.x = PI * 0.5
_cone_mesh.position.z = length * -0.5
func update_cone() -> void:
var a = deg2rad(spot_angle)
var b = PI * 0.5
var c = PI - (a + b)
_cone_mesh.mesh.top_radius = 0.0
_cone_mesh.mesh.bottom_radius = length * sin(a) / sin(c)
_cone_mesh.mesh.height = length
Thank you!
I will try your code this weekend.
Gamemap | 2022-05-12 16:02
