Fix the infamous white edge of death

Author: aaronfranke

model/mesh/material_4d.cpp

@@ -10,9 +10,12 @@ Color Material4D::get_albedo_color_of_edge(const int64_t p_edge_index, const Ref
 		}
 		return Color(1, 1, 1, 1);
 	}
+	// If the above if statement was not hit, then we are using the albedo color array.
+	// Check if we have already cached the per-edge albedo colors.
 	if (p_edge_index < _edge_albedo_color_cache.size()) {
 		return _edge_albedo_color_cache[p_edge_index];
 	}
+	// If not, we need to compute and cache them depending on the source flags.
 	ERR_FAIL_COND_V_MSG(p_for_mesh.is_null(), _albedo_color, "Material4D: Mesh is null.");
 	const PackedInt32Array edge_indices = p_for_mesh->get_edge_indices();
 	const int64_t edge_count = edge_indices.size() / 2;
@@ -48,7 +51,8 @@ Color Material4D::get_albedo_color_of_edge(const int64_t p_edge_index, const Ref
 		_edge_albedo_color_cache.resize(edge_count);
 		_edge_albedo_color_cache.fill(Color(1, 1, 1, 1));
 	}
-	return _albedo_color;
+	// Now that we have cached the per-edge albedo colors, return the requested one.
+	return _edge_albedo_color_cache[p_edge_index];
 }
 
 bool Material4D::is_default_material() const {

render/wireframe_canvas/wireframe_canvas_rendering_engine_4d.cpp

@@ -3,7 +3,7 @@
 #include "../../model/mesh/wire/wire_material_4d.h"
 #include "wireframe_render_canvas_4d.h"
 
-Color _get_material_edge_color(const Ref<Material4D> &p_material, const Ref<Mesh4D> &p_mesh, int p_edge_index) {
+Color WireframeCanvasRenderingEngine4D::_get_material_edge_color(const Ref<Material4D> &p_material, const Ref<Mesh4D> &p_mesh, int p_edge_index) {
 	if (p_material.is_null()) {
 		return Color(1.0f, 1.0f, 1.0f);
 	}
@@ -46,7 +46,7 @@ void WireframeCanvasRenderingEngine4D::render_frame() {
 	for (int mesh_index = 0; mesh_index < mesh_instances.size(); mesh_index++) {
 		MeshInstance4D *mesh_inst = Object::cast_to<MeshInstance4D>(mesh_instances[mesh_index]);
 		ERR_CONTINUE(mesh_inst == nullptr);
-		Ref<Material4D> material = mesh_inst->get_active_material();
+		const Ref<Material4D> material = mesh_inst->get_active_material();
 		Projection mesh_relative_basis = mesh_relative_basises[mesh_index];
 		Vector4 mesh_relative_position = mesh_relative_positions[mesh_index];
 		const PackedVector4Array camera_relative_vertices = Transform4D(mesh_relative_basis, mesh_relative_position).xform_many(mesh_inst->get_mesh()->get_vertices());
@@ -141,7 +141,7 @@ void WireframeCanvasRenderingEngine4D::render_frame() {
 			continue;
 		}
 		edge_colors_to_draw.push_back(edge_colors);
-		Ref<WireMaterial4D> wire_material = material;
+		const Ref<WireMaterial4D> wire_material = material;
 		if (wire_material.is_valid()) {
 			edge_thicknesses_to_draw.push_back(wire_material->get_line_thickness() > 0.0f ? wire_material->get_line_thickness() : -1.0f);
 		} else {

render/wireframe_canvas/wireframe_canvas_rendering_engine_4d.h

@@ -8,6 +8,8 @@
 class WireframeCanvasRenderingEngine4D : public RenderingEngine4D {
 	GDCLASS(WireframeCanvasRenderingEngine4D, RenderingEngine4D);
 
+	Color _get_material_edge_color(const Ref<Material4D> &p_material, const Ref<Mesh4D> &p_mesh, int p_edge_index);
+
 protected:
 	static void _bind_methods() {}