Error: Size of vertex data provided (*) does not match expected (*)

[theraot]

Godot version

v4.2.dev.custom_build [6b727eb] (master at the time of writing)

System information

Godot v4.2.dev (6b727eb) - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1050 Ti (NVIDIA; 31.0.15.3742) - Intel(R) Core(TM) i3-6100 CPU @ 3.70GHz (4 Threads)

Issue description

Using an ImmediateMesh, and setting normals with surface_set_normal, results in error of the form:

Size of vertex data provided (#) does not match expected (##)

Where the # symbols represent numbers, such that # is lower than ##, the actual numbers depend on what other information is being passed about the vertex.

Examples of errors:

• The error where I discovered it:

  Size of vertex data provided (72) does not match expected (120)

• The error on the minimal reproduction project:

  Size of vertex data provided (36) does not match expected (48)

Note: v4.2.dev6.official [57a6813] is not affected.

Steps to reproduce

Add the following code to a MeshInstance and execute the scene:

extends MeshInstance3D


var _immediate_mesh:ImmediateMesh


func _ready() -> void:
	_immediate_mesh = ImmediateMesh.new()
	mesh = _immediate_mesh



func _process(_delta: float) -> void:
	_immediate_mesh.clear_surfaces()
	_immediate_mesh.surface_begin(Mesh.PRIMITIVE_TRIANGLES)
	_immediate_mesh.surface_set_normal(Vector3(0, 1, 0))
	_immediate_mesh.surface_add_vertex(Vector3(0, 0, 0))
	_immediate_mesh.surface_add_vertex(Vector3(0, 0, 1))
	_immediate_mesh.surface_add_vertex(Vector3(1, 0, 1))
	_immediate_mesh.surface_end()

Minimal reproduction project

TesIMesh.zip

[theraot]

This happens in Forward +, Mobile, and Compatibility, which suggest it is an issue on the mesh creation side, not the rendering side. And looking at git blame suggest this might have been introduced by #81138