n64_base.gdshaderinc: Removed redundant LIGHT_VOLUME flag behaviour

`LIGHT_VOLUME` is required for PSX shaders as light volumes there
share vertex shader behaviour, but this doesn't apply to N64 shaders

Author: MenacingMecha

shaders/n64_base.gdshaderinc

@@ -95,9 +95,7 @@ void fragment()
 	ALBEDO = (color_base * texture_color).rgb;
 #endif
 
-#ifdef LIGHT_VOLUME
-	ALPHA = 1.0 - UV.y;
-#elif defined(ALPHA_BLEND) || defined(ALPHA_SCISSOR)
+#if defined(ALPHA_BLEND) || defined(ALPHA_SCISSOR)
 	ALPHA = texture_color.a * color_base.a;
 #endif
 

world/box/sparkle_mat.tres

@@ -9,6 +9,7 @@ shader = ExtResource("1")
 shader_parameter/modulate_color = Color(1, 1, 1, 1)
 shader_parameter/uv_scale = Vector2(1, 1)
 shader_parameter/uv_offset = Vector2(0, 0)
+shader_parameter/uv_pan_velocity = Vector2(0, 0)
 shader_parameter/billboard = true
 shader_parameter/y_billboard = false
 shader_parameter/alpha_scissor = 0.1