Unreal CSV Import Issues

2026-01-15 09:44 UTC gpt-5-2-thinking Open in ChatGPT ↗

That DataTable Import dialog usually “blocks you” for one of two reasons:

1) The Import / OK button is disabled (can’t proceed)

This almost always means Unreal doesn’t have a valid Row Struct to use.

Fix (Blueprint-only)

Create a struct: Content Browser → Add → Blueprints → Structure.
Add variables whose names match your CSV headers (e.g., Damage, Cost, etc.).
Create the DataTable first: Add → Miscellaneous → Data Table → pick your struct as the Row Type.
Open the DataTable → Reimport (or right-click the DataTable asset → Reimport). citeturn0search9

Fix (C++)

Your row type must be a USTRUCT derived from FTableRowBase. citeturn0search1

USTRUCT(BlueprintType)
struct FMyRow : public FTableRowBase
{
  GENERATED_BODY()

  UPROPERTY(EditAnywhere, BlueprintReadWrite)
  int32 Cost = 0;

  UPROPERTY(EditAnywhere, BlueprintReadWrite)
  float Damage = 0.f;
};

CSV gotchas that also prevent import:

Header row must match property names.
First column is typically the row key (often named Name in exported tables).

2) The dialog appears, but you can’t interact / can’t “get through”

This is commonly a UI scaling / off-screen modal issue (high DPI, multiple monitors).

Try these in order:

Bring hidden modal forward
- Alt+Tab until you land on the import dialog (it can hide behind the editor).
Move an off-screen dialog (Windows)
- Focus the dialog via Alt+Tab, then press Alt+Space → M, use arrow keys to move it back, click to drop it.
Reset Unreal layout
- Window → Load Layout → Default Editor Layout
Fix DPI scaling
- Unreal: Window → Developer Tools → Widget Reflector → Application Scale (try 0.8–1.0). citeturn0search2
- If you’re on mixed-resolution monitors, popups can open off-screen; temporarily changing resolution can pull them back. citeturn0search14

3) If the CSV itself is the problem (Excel export issues)

Excel sometimes saves CSVs in a way Unreal chokes on; a common workaround is:

Open the CSV in Notepad (or another editor) and Save again, or export via LibreOffice/Google Sheets. citeturn0search5turn1search4

If you tell me your OS (Windows/macOS/Linux) and whether the button is greyed out vs the window is stuck/off-screen, I’ll point you to the exact shortest fix path—but the steps above cover the most common causes.

Yep — DataTables always need a row key. In Unreal that key is the Row Name (an FName) and it’s not part of your struct; it’s the map key Unreal uses to look rows up. citeturn0search5turn0search13

What to do in your CSV

Make the first column your row key:

Header must be Name (Unreal treats column 1 as the row name). citeturn0search10
Every value in that column must be unique.
Keep them simple (letters/numbers/underscore). Spaces can cause annoyance in lookups.

Example:

Name,Damage,Cost,Description
Sword_01,25,100,"Basic sword"
Sword_02,40,250,"Steel sword"

If you already have an “ID” column

Use that as the Row Name instead (rename that column to Name) and remove the duplicate ID field from your struct if you don’t need it twice.

Why Unreal “adds a Row Name column”

If your CSV doesn’t provide a proper first Name column, Unreal may try to invent/shift things and you’ll see it creating a “Row Name” column in the imported table, which feels like it’s “blocking” progress. citeturn0search0turn0search12

If you paste your first 2–3 lines of the CSV header + one row, I can tell you exactly what needs to be renamed/reordered.

“Current frame” can mean a few different things in Unreal, and the right Blueprint approach depends on which system you mean. Here are the common cases and how to do each in Blueprints.

1) Current game/render frame number (like an ever-increasing counter)

Unreal has an internal frame counter (e.g., GFrameCounter), but it’s not exposed as a standard Blueprint node.

Blueprint-friendly alternatives:

Make your own counter: add an int variable (e.g., FrameIndex) and on Event Tick do FrameIndex += 1.
- This gives you “ticks since BeginPlay”, not “render frames” if tick is throttled/paused, but it’s usually what people want.
If you truly need the engine’s frame counter in BP, you typically use a small C++/BlueprintFunctionLibrary (or a plugin) to expose it.

2) Current frame in a Level Sequence / Sequencer

This one is clean in Blueprints.

On your Level Sequence Player:

Use Get Playback Position (or Get Current Time, depending on version).
You’ll get a time value (often an FQualifiedFrameTime / frame-time).
Convert to frames using the sequence’s frame rate:

Conceptually:

CurrentFrame = Floor( TimeInSeconds * FrameRate )

Practical BP approach:

Get playback position/time
Get the sequence/display Frame Rate
Convert and floor to int

(Exact node names vary slightly by UE version, but “Playback Position/Current Time” + “Frame Rate” is the combo.)

3) Current “frame” of an Animation (Anim Sequence / Montage)

Animations are time-based too:

Anim Montage: use Montage Get Position (seconds) and convert to frames with the animation’s rate if you really want frames.
Anim Sequence: you usually track Time Remaining / Current Time in the AnimBP; “frame index” isn’t the native unit.

4) If what you really mean is “which frame of time at X FPS”

Because FPS can vary, “current frame” is unstable unless you define a frame rate.

Use Get Game Time in Seconds
Decide an FPS (e.g., 60)
Frame = Floor(GameTimeSeconds * 60)

If you tell me which one you mean:

global game frame counter, Level Sequence frame, or animation frame
…I’ll give you the exact node chain for your UE version.

In Blueprints you usually “parse” a DataTable in one of these ways:

1) Iterate every row (most common)

Drag your DataTable reference into the graph.
Use Get Data Table Row Names → gives an array of row names.
ForEachLoop over that array.
Inside the loop, use Get Data Table Row:
- Data Table = your table
- Row Name = current element
- Out Row = your struct data
Do whatever you need with Out Row.

That’s the standard “read all rows” pattern.

2) Read one specific row by key

If you already know the row name (e.g., "Sword_01"):

Get Data Table Row with that row name.

3) Convert rows to an array of structs (handy for sorting/filtering)

Same as #1, but you Add each Out Row into an array variable of your struct type.

Common gotchas

Make sure your DataTable Row Struct matches what you expect (same struct type you created/imported with).
If Get Data Table Row returns false, the row name doesn’t exist (often whitespace/case mismatch).
Row names are Name type; if you have strings, convert with String → Name (or store as Name).

If you tell me what you’re trying to do with the rows (spawn actors, build UI list, find max value, etc.), I’ll suggest the cleanest pattern (and where to put it: Actor BP vs GameInstance vs Widget).

In each frame of Tick, I want to get the all rows whose “frame” column matches my current game frame, split them so that I get “x” and “y” and push these into an array.

sample: 000000,00000,00,-188.7032,-227.9918 000001,00000,01,231.0830,-184.8418 000002,00000,02,-273.8828,-110.7300 000003,00000,03,295.4238,11.3456 000004,00000,04,236.4773,177.2389 000005,00000,05,-288.5535,-65.5447 000006,00000,06,-191.2853,225.1407 000007,00000,07,181.4515,-233.9608 000008,00000,08,-33.0378,295.1567 000009,00001,00,-187.2686,-227.8242 000010,00001,01,230.7526,-183.5203 000011,00001,02,-272.3634,-110.2600 000012,00001,03,294.0954,10.5669 000013,00001,04,235.1244,176.5849 000014,00001,05,-287.9055,-64.0012 000015,00001,06,-190.9147,223.3959 000016,00001,07,180.4017,-233.6092 000017,00001,08,-33.4581,293.9804 000018,00002,00,-185.8340,-227.6563 000019,00002,01,230.4225,-182.1987 000020,00002,02,-270.7862,-110.0560 000021,00002,03,292.7660,9.7898 000022,00002,04,233.7714,175.9309 000023,00002,05,-287.3856,-62.4100 000024,00002,06,-190.5445,221.6510 000025,00002,07,179.3558,-233.2457 000026,00002,08,-33.8695,292.8009

What you want is doable, but don’t scan the entire DataTable every Tick. Instead:

Pre-index the table once (BeginPlay): build a Map<Frame, Array<Vector2D>>
On Tick: compute your current frame and do a fast Map Find → gives you all (x,y) for that frame.

Below is the clean Blueprint pattern.

0) Set up the DataTable struct

Your CSV rows look like:

RowId, Frame, PointId, X, Y

Make a struct like:

RowId (String or Name) (optional)
Frame (Int or String)
PointId (Int or String) (optional)
X (Float)
Y (Float)

Import tip: first CSV column is row key (“Name”) for the DataTable. If your first column is that 000000 unique id, that’s perfect for the row name; keep it as the first column (or name it Name).

1) Build an index map (BeginPlay)

Create variables:

FrameToPoints (Map)
- Key: int (Frame)
- Value: Array of Vector2D
PointsThisFrame (Array of Vector2D)
CurrentFrame (int)

BeginPlay graph:

Get Data Table Row Names (YourDataTable) → RowNames
ForEachLoop(RowNames)
Inside loop:
- Get Data Table Row (YourDataTable, ArrayElement) → OutRow (your struct)
- Convert OutRow.Frame to int if it’s a string like "00001":
  - String To Int (Blueprint node)
    - If it’s a Name, do Name To String first.
- Make Vec2D = Make Vector2D(OutRow.X, OutRow.Y)
- Add to map:
  - Map Find (FrameToPoints, FrameInt)
    - If found: get the array, Add(Vec2D), then Map Add back (or modify via “Set Array Elem” pattern)
    - If not found: make a new array with Vec2D, then Map Add(FrameInt, NewArray)

Result: for frame 1, you’ll have 9 points (PointId 00..08), etc.

2) On Tick: grab all points for the current frame

Compute current game frame

Simplest (your own counter):

Event Tick
- CurrentFrame += 1

Or if you want “frame at fixed FPS” (e.g. 60fps timeline):

CurrentFrame = Floor( GetGameTimeInSeconds * 60 )

Fetch points

Map Find (FrameToPoints, CurrentFrame)
- If found: PointsThisFrame = FoundArray
- Else: PointsThisFrame = Empty (Clear)

Now PointsThisFrame is your array of all (x,y) for that frame.

3) If you need X[] and Y[] separately

From PointsThisFrame:

ForEachLoop
- Break Vector2D
- Add X to Xs array, Y to Ys array

(But usually keeping Vector2D is nicer.)

Why this is the right approach

BeginPlay cost: O(N rows) once
Per Tick cost: O(1) lookup + copying array (or even just use the found array)

If you tell me your struct field types (is Frame currently a String, Name, or Int?) I can tell you the exact conversion nodes to use so Map Find always hits.

In Blueprints you can absolutely do that — a Map value can be an Array.

Create the variable type

In My Blueprint panel → + Variable
In the variable’s Type dropdown, search and pick Map
Set:
- Key Type = Integer (or Name, whatever your “frame” is)
- Value Type = Vector2D (or your struct)
Now click the container icon next to the Value Type and change it to Array.
- You’ll end up with:
  Map (Integer → Array of Vector2D)

That’s it: TMap<int, TArray<FVector2D>> equivalent.

Adding an element to “Map<int, Array<…>>” (Blueprint pattern)

Because you can’t directly “Add to array inside map” in one node, use this pattern:

Given: FrameToPoints (Map int → array of Vector2D)

Find
- Map Find (FrameToPoints, FrameInt) → Found?, PointsArray
If Found?
- Add (PointsArray, NewVec2D)
- Map Add (FrameToPoints, FrameInt, PointsArray) (writes updated array back)
Else
- Make Array (with NewVec2D)
- Map Add (FrameToPoints, FrameInt, NewArray)

That “Find → modify local copy → Add back” is the standard BP way.

If you tell me what you want as the value type (Vector2D vs your own struct), I can write the exact node chain you’ll need to build the index from the DataTable.

Yeah — that’s not you. Blueprints don’t let you make “nested containers” directly, so you can’t have a variable that is literally:

Map<Int, Array<Vector2D>>

That’s why you don’t see an “array” icon next to the Map’s value type.

The Blueprint workaround (standard)

Wrap the array inside a Struct, then map to that struct:

1) Create a struct

Add → Blueprints → Structure
Name it something like S_FramePoints
Add a variable:
- Points : Vector2D with Array enabled

So the struct is basically:

Points : Vector2D[]

2) Make your map use that struct as the value

Create variable FrameToPoints:

Container: Map
Key: Integer
Value: S_FramePoints

Now you effectively have:
Map<Int, S_FramePoints>, and inside each value is an array.

Adding a Vector2D to the map at runtime (pattern)

Given FrameInt and NewPoint (Vector2D):

Find
Map Find (FrameToPoints, FrameInt) → Found? + ValueStruct
Branch

If Found
- Get ValueStruct.Points
- Add NewPoint to that array
- Set it back into ValueStruct (use Set Members in S_FramePoints)
- Map Add (FrameToPoints, FrameInt, ValueStruct) ✅ (write back)
If Not Found
- Make new array with NewPoint
- Make S_FramePoints with Points = NewArray
- Map Add (FrameToPoints, FrameInt, NewStruct)

That “Find → modify → Add back” is the normal BP workflow.

If you want, tell me your UE version (5.0/5.1/5.2/5.3/5.4/5.5) and I’ll name the exact nodes as they appear (some are labeled slightly differently).

You’ve got ValueStruct (type S_FramePoints) coming out of Map Find. To get the Points array out of it:

Method A: Split / Break the struct (quickest)

Drag off ValueStruct
Search “Break S_FramePoints” (or right-click the pin and choose Split Struct Pin)
You’ll get an output pin called Points (an array of Vector2D)

That Points pin is the array.

Method B: Drag the member directly (if it’s a variable)

If you have a S_FramePoints variable:

Drag it into the graph (Get)
Drag off it and search “Points” — you’ll see Get Points (or Break option)

Important gotcha

The array you get from Break is basically a copy. If you modify it (Add/Remove), you still need to:

Put it back into a struct (Make S_FramePoints or Set Members in S_FramePoints)
Then Map Add back into the map with the same key

Typical “Found” flow

Map Find → ValueStruct
Break S_FramePoints → PointsArray
Add to PointsArray
Set Members in S_FramePoints (Points = PointsArray) → UpdatedStruct
Map Add (Key = FrameInt, Value = UpdatedStruct)

If you show (or describe) your exact nodes around Map Find, I can tell you which one to click (Split pin vs Break node) for your layout.

Here’s the exact Blueprint “Not Found” path, step by step.

Assume you have:

FrameToPoints : Map (Int → S_FramePoints)
FrameInt : Int
NewPoint : Vector2D
S_FramePoints has a member Points : Vector2D Array

When `Map Find` returns Not Found

Make a new array with your point

Add a node: Make Array
Set the array element type to Vector2D
Plug NewPoint into element [0]

Make a new struct

Add node: Make S_FramePoints
Plug the output of Make Array into the Points pin

Put it into the map

Use Map Add
- Map = FrameToPoints
- Key = FrameInt
- Value = output of Make S_FramePoints

That’s it.

Node chain (text form)

(Not Found) → Make Array (Vector2D) → Make S_FramePoints (Points = Array) → Map Add (FrameInt, Struct)

Small tip

If you don’t see Make S_FramePoints, right-click in the graph and search the struct name, or drag off a S_FramePoints pin and search “Make”.

If you want, I can sketch the Found + Not Found combined flow in one clean chain (with the “write back” step) so you can copy it exactly.

You can make it “8 rows at a time”, but there are two important realities:

A DataTable isn’t stored as the original CSV at runtime. It’s already an asset. So you’re not really “parsing the file” anymore.
Blueprints don’t have a great built-in “read arbitrary CSV from disk at runtime” unless you use C++ or a plugin.

So the simplest runtime approach in pure Blueprints is:

Option A (simple + fast): “Cursor” through rows, take next 8

This avoids a Map-of-Arrays and avoids scanning the whole table every Tick.

One-time setup (BeginPlay)

Get Data Table Row Names → RowNames
Sort RowNames
- (Works well because your row IDs are zero-padded: 000000, 000001, …)
Store:
- SortedRowNames (Name Array)
- Cursor (Int, start at 0)

Each Tick

PointsThisFrame → Clear
Loop i = 0..7:
- Index = Cursor + i
- RowName = SortedRowNames[Index]
- Get Data Table Row → OutRow
- If OutRow.Frame != CurrentFrame → break (stop early)
- Else:
  - Make Vector2D(OutRow.X, OutRow.Y) → Add to PointsThisFrame
After loop:
- Cursor += 8 (or set it to wherever you stopped)

This works best if your data is already grouped by frame (it is, in your sample).

Note: Your sample shows 9 points per frame (00..08), not 8. If you truly need 8, decide which one to skip (or read 9).

Option B (true “parse CSV at runtime”)

If you literally want to read a .csv text file while the game is running:

In Blueprint-only, you usually need a plugin (common on Marketplace) or you’ll be fighting file access.
In C++, it’s straightforward: read file → split lines → split commas → convert to numbers.

If you want, tell me which you mean:

“Keep DataTable asset, just read 8 rows per tick” → I’ll outline the exact BP nodes including the “break” flow.
“Load an external CSV file at runtime (packaged game)” → I’ll give you the cleanest C++ + BP-exposed function pattern (and file location rules).

In Blueprint there isn’t a built-in “Merge Exec” node like you’re imagining. Exec pins are directional and Blueprint wants each path to be explicit.

That said, there are a few clean patterns that accomplish the same thing:

1) Reroute node (only for tidying wires)

Double-click an exec wire to create a Reroute Node.
This does not merge multiple exec inputs into one; it just makes lines cleaner.

2) Use a Function / Custom Event as the “join point” (most common)

If you have multiple branches that should all end up doing the same thing, call the same Function or Custom Event from each branch.

Example:

Branch A → Call DoCommonThing
Branch B → Call DoCommonThing
Branch C → Call DoCommonThing

That’s effectively a “merge”, and it’s the idiomatic BP way.

3) Gate / DoOnce / Sequence (depending on what you mean)

These don’t literally merge, but they can simplify control flow:

Gate: multiple execs can all go into “Enter” (you can route them through separate wires) and only pass when open.
DoOnce: if you’re merging to ensure it only runs once.
Sequence: for splitting one exec into many, not merging.

4) Macro that acts like a join (only if you really want one input pin)

You can create a Macro with multiple Exec inputs and one Exec output (a “Join”).
But be careful: if two inputs fire in the same frame, you’re defining your own ordering (often “last one wins” depending on how you wire it). This can hide bugs.

How:

Create a Blueprint Macro Library (or a Macro inside your BP).
Add multiple Exec Inputs (e.g., A, B, C) and one Exec Output.
Inside, route each input to the single output.

This works, but it’s mostly cosmetic.

Recommendation

If you want a “passthrough merge” for readability: use a Function/Custom Event as the join point. It stays clear and safe.

If you tell me your exact use case (e.g., “both True and False should continue here” or “after multiple async callbacks continue”), I’ll suggest the cleanest pattern for that situation.

This usually comes down to when you’re creating the MID and whether anything is still holding a reference to it.

Why your MIDs “don’t persist” (and you get errors)

1) You created the MID, but didn’t store it anywhere (GC / “Accessed None” later)

If you create a Dynamic Material Instance and only keep it in a local variable (or you don’t assign it to a mesh), it can get garbage collected / you lose the reference.

Fix

Promote the return value to a Blueprint member variable (e.g. MyMID of type MaterialInstanceDynamic), or store an array if you have multiple.
And/or make sure you Set Material on the component with that MID.

Best node for this is the component version:

On your Mesh component: Create Dynamic Material Instance (Element Index)
This both creates it and (typically) assigns it to that element, then returns the MID—store that return value.

2) You’re trying to change parameters “in the editor” but the MID is only created in BeginPlay

BeginPlay does not run in the editor (outside PIE/SIM). So when you tweak a Detail value, your code (often Construction Script / “OnConstruction”) runs and tries to use MyMID, but it’s null, so you get errors like “Accessed None”.

Fix options

If you want live editor preview: create/get the MID in the Construction Script (or a function called by it), not just BeginPlay.
Or guard your parameter-setting code with IsValid(MyMID) and create it if missing.

Typical pattern in Construction Script:

If NOT IsValid(MyMID) → Create Dynamic Material Instance → store to MyMID
Then set your scalar/vector params on MyMID

3) You’re accidentally overwriting the MID later

If somewhere in Tick/BeginPlay/Construction you call Set Material again with the base material (or another MI), you replace the MID and then your stored reference no longer matches what’s on the mesh.

Fix

Only set the material once (to the MID), then only edit parameters on the MID afterward.
If multiple elements: keep an array MIDs[ElementIndex].

Quick “do this” checklist

✅ Use Mesh → Create Dynamic Material Instance (Element Index)
✅ Promote the returned MID to a member variable (or array)
✅ If you need editor-time tweaking: do the creation + param set in Construction Script (with IsValid guard)
✅ Don’t overwrite the mesh material afterward with the base material

If you paste the exact error text (or a screenshot) and say whether you’re setting params in Tick or Construction Script, I can point to the exact node that’s breaking.

Construction Script is a special Blueprint graph that runs when the Actor is constructed or updated, not when the game starts.

What it is

It runs:
- when you place an Actor in a level
- when you move it / change properties in the Details panel
- when the level loads
- when you spawn the Actor (it runs during spawn, before BeginPlay)
It does not run every frame like Tick.
In C++ terms it’s essentially OnConstruction (plus some editor-time behavior).

Where to find it

Open your Actor Blueprint → in the graph list you’ll see:

Construction Script (separate from Event Graph)
In UE5 it may appear as a tab/graph named Construction Script.

Why it matters for your MID + editor tweaks

BeginPlay only runs in PIE / Simulate / packaged game.
When you “change a value in the editor,” Unreal reruns the Construction Script to rebuild/update the Actor.
If your code that sets material parameters runs in the editor (Construction Script / OnConstruction or via property change), but the MID is only created in BeginPlay, then MyMID is null → “Accessed None” errors.

So the rule of thumb:

BeginPlay: runtime-only init (safe for gameplay)
Construction Script: editor-time + spawn-time setup (good for previewing changes in the editor)

Why I kept saying BeginPlay earlier

For many “initialize once for gameplay” tasks, BeginPlay is the right default, because Construction Script can rerun a lot in-editor and can accidentally do expensive work. But for anything you expect to update while tweaking values in the editor (like material params), Construction Script (or OnConstruction) is the right place—with a validity guard.

A good MID pattern (Blueprint)

In Construction Script:

If NOT IsValid(MyMID) → Create Dynamic Material Instance on the mesh → store in MyMID
Set Scalar/Vector Parameter Value on MyMID using your exposed variables

In BeginPlay (optional):

If you don’t need editor preview, you can do it all here instead.

If you tell me which component you’re applying the material to (StaticMeshComponent? SkeletalMeshComponent? multiple elements?), I’ll describe the exact node chain and where each piece should live.

Yes — with a caveat: Niagara’s Emitter “Max Particles” is mainly an allocation/safety cap and isn’t something you typically “dial live” in Blueprints. The usual (and better) way is to make your own User parameter that controls how many particles you spawn / keep alive, and then drive that from a slider.

The clean workflow (slider → Niagara)

1) Add a User parameter to your Niagara System

In the Niagara System → System Settings → User Parameters, add:

User.MaxParticles (Int32) (or Float)

User parameters are specifically meant to be set from Blueprint/C++ outside the sim. citeturn1search3

2) Use that parameter to control particle count

Pick one:

A) Steady-state “cap-ish” via Spawn Rate (good for continuous effects)

If your particle lifetime is roughly constant, steady count ≈ SpawnRate * Lifetime.
So set your Spawn Rate to:
SpawnRate = User.MaxParticles / LifetimeSeconds

(Implement this by wiring User.MaxParticles into your Spawn Rate module math.)

B) Exact count via Burst (good for “spawn N and hold”)

Use Spawn Burst Instantaneous and set Count = User.MaxParticles.

Important: Set the emitter’s built-in Max Particles high enough to cover your slider’s max, otherwise Niagara will clamp internally.

3) In Blueprint, set the User parameter from a slider

If you have a Niagara Component in your Actor:

On slider change (UMG OnValueChanged) or in editor tweaks:
- Call Set Niagara Variable (Int32) (or Float) on the Niagara component
- Variable Name: User.MaxParticles
- Value: slider value

Epic’s Blueprint API node is literally “Set Niagara Variable (Float)” / “Set Niagara Variable (Int32)”. citeturn1search8turn1search2

Example: UMG Slider hookup (common)

Create Widget with Slider (0..1)
Convert to range you want: MaxParticles = Round( Lerp(Min, Max, SliderValue) )
NiagaraComponent → Set Niagara Variable (Int32):
- In Variable Name = User.MaxParticles
- In Value = MaxParticles

Bonus: if you want a slider in the Details panel (no UMG)

You can expose a BP variable (Instance Editable) and set its Slider Range in the variable details, then in Construction Script / BeginPlay push it into Niagara with Set Niagara Variable….

If you tell me whether your effect is continuous (smoke/rain) or burst/static (spawn N points), I’ll recommend the exact Niagara module setup (Spawn Rate math vs Burst) so the slider feels “true max particles” instead of “sort of”.

Yes — in Niagara Sprite Renderer you can “expose” material parameters in two different ways, depending on whether you need per-emitter control or per-particle control.

1) Per-emitter (or per-system) parameters: Material Parameter Bindings

This is the “proper” way to drive regular material parameters (Scalar/Vector/Texture params) from Niagara.

Steps

In the Material
- Use Scalar Parameter / Vector Parameter nodes (named e.g. Glow, Tint).
- Make sure the material has Use with Niagara Sprites enabled. citeturn0search4
In Niagara (System/Emitter)
- Create variables at User / System / Emitter scope, e.g. User.Glow (float), User.Tint (LinearColor).
In the Sprite Renderer
- Select the Sprite Renderer → go to Bindings → Material Parameter Bindings / Material Parameters
- Add an entry:
  - Material Parameter Name = exactly your material param name (e.g. Glow)
  - Niagara Variable = User.Glow (or System/Emitter variable)

Niagara will create a MID per emitter instance and push those values into it. citeturn0search8turn0search13

✅ Great for: “one slider controls the whole emitter/system” (performance testing, global intensity, etc.)
⚠️ Limitation: this binding is typically not per-particle; it’s meant for User/System/Emitter values. citeturn0search13turn0search0

2) Per-particle parameters: Dynamic Material Parameters

If you want each particle to have its own values (like a per-particle float4):

Steps

In the Material
- Use Dynamic Parameter node (gives you 4 channels) or Particle Color for RGBA (often better). citeturn0search3turn0search8
In the Sprite Renderer
- In Bindings, set Dynamic Material Binding (and 1/2/3 if needed) to a particle attribute.
In Niagara
- Write to that attribute in Particle Spawn/Update (e.g. set the dynamic material parameter vector4 per particle).

✅ Great for: gradients per particle, random per particle values, age-based material effects

Which one you want?

“Expose params so a slider changes the whole effect”: Material Parameter Bindings (User.* variables)
“Expose params so each particle can be different”: Dynamic Material Parameters / Particle Color

If you tell me what parameter type you’re trying to expose (float, color, texture) and whether it should be per-emitter or per-particle, I’ll give you the exact node/variable names to wire up.

Yes — this is built in.

For a normal mesh (StaticMesh / SkeletalMesh / Actor in the level)

Select the mesh component.
In Details → Rendering:
- Disable Render in Main Pass (or sometimes just Visible off, but prefer Render in Main Pass)
- Enable Cast Shadow

Result: the object won’t be visible to the camera, but it can still cast shadows.

If you need it to cast shadows but not show up in reflections / GI

Also disable as needed:

Visible in Reflection Captures
Visible in Ray Tracing (if using RT)
Visible in Scene Capture (if you’re using SceneCapture2D)

If you only want it hidden for one specific camera / capture

Use the camera’s/SceneCapture’s hidden lists:

On SceneCaptureComponent2D: Hidden Actors / Show Only Actors
For gameplay cameras, you can use Owner No See / Only Owner See (more for characters)

Niagara / VFX note

If it’s Niagara, you’ll instead control renderer visibility / custom depth etc., but “cast shadows while hidden” is mainly a mesh thing.

If you tell me whether you’re using Virtual Shadow Maps / Lumen / Ray Tracing, I can point out the one extra checkbox that sometimes matters (“Visible in Ray Tracing” in particular).

Those two circles at the bottom-left/right are almost certainly the mobile virtual joysticks / touch interface.

Remove the circles (virtual joysticks)

Project Settings way (recommended):

Edit → Project Settings
Go to Input
Scroll to Mobile
Set Default Touch Interface to None (clear “DefaultVirtualJoysticks”). citeturn0search2turn0search4turn0search10

Blueprint way (if you want to toggle at runtime):

On your Player Controller call Activate Touch Interface and set it to None. citeturn0search2turn0search1

Hide errors / warnings on the screen

If you mean the red/yellow on-screen engine messages (lighting rebuild, blueprint warnings, “ScreenMessages” etc.):

Quick: console command

Open the in-game console ( ` key ) and run:

DisableAllScreenMessages citeturn0search16turn0search0

To turn them back on:

EnableAllScreenMessages citeturn0search0turn0search5

Make it automatic every time you press Play

In Level Blueprint → Event BeginPlay:

Execute Console Command → DisableAllScreenMessages citeturn0search0turn0search3

If you can screenshot the circles + the exact warning text you’re seeing, I can tell you whether it’s touch interface vs something like a debug overlay / widget—but 99% of the time those circles are the Default Touch Interface.

You can, but you have to decide what you mean by “enforce” (camera view vs game window vs UI). Here are the practical Unreal ways:

1) Force the camera view to be square (1:1) with letterboxing

This is the usual approach.

On your CameraComponent (or CineCamera):

Enable Constrain Aspect Ratio
Set Aspect Ratio to 1.0

Result: on a non-square monitor, Unreal will add black bars (letterbox/pillarbox) so the rendered view stays square.

Tip: If you’re using a CineCameraActor, you can also set the filmback / sensor settings, but “Constrain Aspect Ratio = 1.0” is the direct solution.

2) Force the game window to be square (actual 1:1 viewport)

If you want the whole window itself to be square:

Project Settings (startup size)

Project Settings → Platforms → Windows
- Set Default Window Width and Default Window Height to the same value (e.g., 1024 × 1024)

Runtime (Blueprint)

Use Execute Console Command:
- r.SetRes 1024x1024w (w = windowed)
- or r.SetRes 1024x1024f (f = fullscreen)

Or via Game User Settings nodes:

Get Game User Settings
Set Screen Resolution (IntPoint 1024,1024)
Apply Settings

If you mean a UI element should stay 1:1:

Put it in a SizeBox (set Width/Height override to same, or bind one to the other)
Wrap with a ScaleBox (Stretch = Scale To Fit) if you want it to scale while staying square.

Which one do you want?

Square camera view (with black bars) → option 1
Square window (actual viewport is square) → option 2
Square UI element → option 3

Tell me which you’re aiming for (camera vs window vs UI) and whether you’re in UE4 or UE5, and I’ll give the exact node/setting names for your setup.

Yep — the easiest way is a built-in stat overlay.

Fastest (during play)

Press ~ to open the console
Type:

stat fps

Type it again to hide it (it’s a toggle). citeturn0search3turn0search2

Slightly more useful

stat unit (CPU/GPU frame times)
stat unitgraph (graph) citeturn0search7turn0search9

Auto-enable every time you press Play

In Level Blueprint → Event BeginPlay:

Execute Console Command → stat fps citeturn0search2turn0search1

Note (PIE quirk): in the editor, stat fps can “stick” between play sessions and behave like it’s toggling every other time, because it affects the editor viewport too. In a packaged build it behaves normally per run. citeturn0search0turn0search5

If you want an FPS counter that works even in Shipping without relying on the stat system, you can also compute it as 1 / GetWorldDeltaSeconds and print it in a widget. citeturn0search4turn0search2

Yes — you can cap the game to 60 FPS. What you can’t do is magically keep 60 if the hardware can’t hit it (then you’ll drop below 60).

Easiest: cap with a console command

In-game console:

t.MaxFPS 60 citeturn0search9turn0search0

Blueprint (BeginPlay):

Execute Console Command → t.MaxFPS 60 citeturn0search9turn0search17

Make it a project setting (persistent)

Project Settings → Engine → General Settings → Framerate

Option A (recommended for most games): Smooth Frame Rate
- Enable it, set the Smoothed Frame Rate Range max to 60 citeturn0search14turn0search12
Option B (use carefully): Use Fixed Frame Rate = 60
- This changes how the engine steps time and can have side effects (especially physics/gameplay timing). citeturn0search12turn0search10

If you also want “locked to display refresh” behavior

Turn on VSync:

r.VSync 1 citeturn0search9
(Useful if you want stable pacing and your monitor is 60 Hz; on higher-Hz monitors it may lock to 120/144/etc instead.)

If you tell me whether this is for profiling Niagara or for a shipping gameplay lock, I’ll point you to the best combo (cap vs smoothing vs VSync) for that goal.

Yes — there are two different kinds of “stuff on screen” in Unreal, and they’re handled differently.

Hide Print String / on-screen debug messages

These are the messages produced by Print String (Blueprint) and AddOnScreenDebugMessage (C++).

Toggle (fastest)

Open the console / Output Log and run:

DisableAllScreenMessages

To turn them back on:

EnableAllScreenMessages citeturn0search2turn0search13

Make it happen automatically on Play

In Level Blueprint → Event BeginPlay:

Execute Console Command → DisableAllScreenMessages citeturn0search2turn0search4

Permanent (config)

In your project Config/DefaultEngine.ini, add:

[/Script/Engine.Engine]
bEnableOnScreenDebugMessages=false
bEnableOnScreenDebugMessagesDisplay=false

These engine flags control on-screen debug message behavior. citeturn0search0

Hide “Lighting needs to be rebuilt” / some engine warnings

Some big editor/game warnings (like “LIGHTING NEEDS TO BE REBUILT”) are not always affected by DisableAllScreenMessages. In that case, the real fix is to resolve the underlying issue (e.g., build lighting / adjust lighting setup). citeturn0search6

If you tell me the exact text of the warnings you still see (screenshot is fine), I’ll tell you which category they’re in and the quickest way to remove that specific one.

Yes — you can hide the spam and keep an FPS counter.

Keep FPS, hide the rest (console / Blueprint)

Do both commands:

Hide screen messages:

DisableAllScreenMessages citeturn0search12

Turn FPS on:

stat fps citeturn0search0turn0search9

In Blueprint (Level BP → BeginPlay)

Add two Execute Console Command nodes in this order:

DisableAllScreenMessages
stat fps

That will typically keep the FPS overlay visible while suppressing Print String / warnings.

If `DisableAllScreenMessages` also hides your FPS in your setup

(Some projects/configs do this.) Easiest workaround: make your own FPS widget (not affected by screen-messages).

On Tick (or a timer), set a Text to:
- FPS = Round( 1 / GetWorldDeltaSeconds )

This stays visible regardless of screen message suppression.

If you tell me whether you’re in PIE, Standalone, or a packaged build, I’ll tell you which of the two approaches is most reliable for your case.

Here’s the quickest “FPS widget” setup in Unreal (Blueprint + UMG). No plugins, no C++.

Content Browser → Add → User Interface → Widget Blueprint
Name it WBP_FPS
Open it → in the Designer:
- Drag a Text widget onto the canvas
- Set its Anchor to top-left (or wherever)
- Give it a readable font size

2) Add a Text variable you can update

Select the Text widget → in Details:

Check Is Variable (so you can reference it in the graph)

3) Update the text with FPS

Go to the Graph tab of WBP_FPS:

Event Construct

Set a timer (better than Tick):
- Set Timer by Event (Time = 0.25, Looping = true)
- Create the event → call it UpdateFPS

UpdateFPS event

Get World Delta Seconds
FPS = 1 / DeltaSeconds
(Optional) Round or FInterp for smoothing
SetText on your Text widget to something like: FPS: 60

Blueprint node flow (conceptually):

Delta = GetWorldDeltaSeconds
FPSFloat = 1.0 / Delta
FPSInt = Round(FPSFloat)
Text = Format Text "FPS: {FPSInt}"

In your Player Controller (recommended) or Level Blueprint:

Event BeginPlay

Create Widget (Class = WBP_FPS)
Add to Viewport
(Optional) Set ZOrder high so it’s always on top

That’s it.

Bonus: hide warnings but keep this FPS

Since this FPS is your own UI, you can still run:

DisableAllScreenMessages …and the widget stays visible.

If you tell me where you want it (top-left/top-right) and whether you want it smoothed (less jumpy), I’ll give you the exact smoothing nodes too.