Unreal Engine ImGui "port" <https://github.com/sronsse/UnrealEngine_ImGui> DESCRIPTION This repository contains an Unreal Engine project with Omar Cornut's ImGui framework (https://github.com/ocornut/imgui) integrated into a HUD class. The code base, by default, will display the test window provided as part of ImGui. Disclaimer: I am not an Unreal Engine nor an ImGui expert, so this code base is by no means guaranteed to be optimal. VERSIONS Please find below the versions of both frameworks which were used: - Unreal Engine v4.15 - ImGui v1.49 KNOWN LIMITATIONS Performance: the ImGui framework will pass index and vertex buffers as part of the command lists to be rendered. Unreal Engine does not seem to support this rather common method of rendering geometry at a high-level. In order to circumvent this issue, each triangle is manually extracted/recomposed from these buffers and rendered via the HUD class DrawMaterialTriangle method. This could severely impact performance. Clipping: part of the command lists to be rendered by ImGui provide as an input a clipping rectangle parameter, which typically is handled through scissoring functions (pixels falling outside of the rectangle are fully discarded). As Unreal Engine does not seem to support clipping rectangles when manually rendering triangle sets, all vertex positions along with their texture coordinates are altered to adapt to ImGui's requirements. While no issues were observed during functional testing, some unsupported edge cases may still exist. Keyboard input: the methods provided by Unreal Engine within the HUD class seem somewhat limited. Rather than implementing an event mechanism with a callback function, the HUD class manually polls for detected scan codes, which does have an impact in performance. Moreoever, the current code base in place deals with scan codes and convert them to UTF8 input on the fly for use with ImGui's text input widgets - this has a huge drawback: some characters simply are not supported at all for now (symbols located above numbers on a QWERTY keyboard in particular). Feedback on how to properly implement a generic input function recognizing all key combinations from that level is welcome. HELP If you need help with this port or would like to submit pull requests, feel free to do so via the github interface or contact me at sronsse@gmail.com.