I’m trying to create a “Wolfenstein 3D” style raycaster on a widget in UE5 Blueprints. I have everything working, which I did using the draw functions in the “On Paint” function. Now I’m trying to add textures to the lines on the raycaster, but the built in Draw Line node doesn’t work for this. I’m working on making a custom node in c++ that could take a texture and a position along the texture and set that as the colors to draw on the line. Is this the most efficient way, and if not what’s an easier way of doing this? I’ve thought about using the “Draw Box” node instead because it uses brushes which can have textures, but I’m not sure how I’d get a specific sliver of the texture to be drawn based on the length along the wall. Any advice?
Hi!
I have previously worked on a similar project.
In general, I only use the OnPaint function for basic and mostly debug related graphics and texts, it is not very optimized.
I would recommend using a UI Material along with the native “Custom” HLSL node (if needed) instead of creating a custom c++ function for this. Using a UI Material would open up many more customization options besides drawing textures or colors along the shapes and it is already optimized.
Here’s a quick overview:
1- Create a Material and make sure its Domain is set to User Interface and Blend Mode is set to Translucent (or Masked).
2- Add an Image widget to the canvas of your custom widget, make sure it covers the screen.
3- On Event Construct or Event PreConstruct, create an instance of the UI Material and save it as a variable.
4- Set the material instance reference as the brush of the Image widget using Set Brush From Material function.
5- Open the UI Material and add a “Custom” HLSL node or use existing nodes and functions depending on the complexity of the shapes you are drawing. I personally prefer using the Custom node which allows me to experiment more and allows adding custom inputs and outputs.
6- Set the parameters of the material instance dynamically, on Tick event for example.
Depending on your use case, you might need to create a material instance and an Image widget per shape, unless you have a predefined number of shapes then the Custom node would just need inputs for the positions of each shape. A better approach would be creating a widget called WB_Shape for example, which would have the Image widget and the dynamic material instance, and a function to set the parameters of the material instance including positions, colors, textures, effects and etc.
I hope this helps!