<cat>Code.Misc</cat> <title>RenderEntity</title> `RenderEntity` is a clientside-only entity class that lets you draw simple meshes. The API is pretty simple and lets you provide dynamic vertex data on a per-frame basis. ## Creating a basic sprite For most use cases it's sufficient to just derive from the `RenderEntity` class and override the `DoRender` method: ```csharp using Sandbox; // It's just a square with a material slapped onto it. public class Sprite : RenderEntity { public Material SpriteMaterial { get; set; } public float SpriteScale { get; set; } = 18f; public bool Enabled { get; set; } = true; public override void DoRender(SceneObject obj) { if (!Enabled || Local.Pawn.Camera is not Camera cam) return; if (!Enabled) return; // Allow lights to affect the sprite Render.SetLighting(obj); Render.SetupLighting(obj); // Create the vertex buffer for the sprite var vb = Render.GetDynamicVB(); // Vertex buffers are in local space, so we need the camera position in local space too var normal = Transform.PointToLocal(cam.Pos).Normal; var normal = Transform.PointToLocal(CurrentView.Position).Normal; var w = normal.Cross(Vector3.Down).Normal; var h = normal.Cross(w).Normal; float halfSpriteSize = SpriteScale / 2; // Add a single quad to our vertex buffer vb.AddQuad(new Ray(default, normal), w * halfSpriteSize, h * halfSpriteSize); // Draw the sprite vb.Draw(SpriteMaterial); } } ``` Then you can spawn them like this: ```csharp // Somewhere in client code... var sprite = new Sprite { SpriteMaterial = Material.Load("materials/goatse.vmat"), SpriteScale = 24f }; ``` Keep in mind that creating RenderEntities serverside does not work-- they simply won't spawn. ## Dynamic expressions If your materials have dynamic expressions, you can write to their variables by calling `Render.Set` inside your `DoRender` method. The values you set will affect all subsequent draw calls in the method body. If your materials have dynamic expressions, you can write to their variables by calling `Render.Attributes.Set` inside your `DoRender` method. The values you set will affect all subsequent draw calls in the method body. ```csharp Render.Set("rendercolor", Color.Red); Render.Attributes.Set("rendercolor", Color.Red); ``` ## Limitations Due to the large size of the `RenderEntity` vertex format, vertex buffers created with `Render.GetDynamicVB()` can only contain approximately 600 vertices. If you exceed this limit, you may experience crashes. If you need more vertices, you can either use multiple vertex buffers or use the `Mesh` class instead (which allows you to use a custom vertex format).