First Frame Rendered with New Renderer! // Renderer 2025 // Hazel Engine Stream (21.05.2025)
/ thecherno
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AI Stream Summary (Claude Sonnet 4)
00:00 Introduction & Project Context
Cherno welcomes viewers back to continuing work on Hazel's renderer rewrite
Explains they've switched from custom Vulkan renderer to NVIDIA's NVRHI backend
Previous stream got the project compiling, now focusing on getting ImGui working
Discusses platform support decisions: Windows/Linux/Mac yes, mobile no (due to past experience pain)
19:00 Architecture Discussion & War Stories
Deep dive into why mobile development was abandoned - horror stories from EA mobile work
Discusses Samsung driver engineers, debugging nightmares, and iOS vs Android development
Explains Frostbite complexity and why they left EA to build Hazel
Thanks community for making independent development possible
51:00 Core Development Work
Implements image_copy_to_host_buffer function for NVRHI
Debugging texture state tracking issues and resource transitions
Working through Vulkan barriers and state management
Discovers texture format differences between linear and sRGB versions
1:56:00 ImGui Integration
Porting ImGui layer from old Vulkan backend to NVRHI
Replacing VulkanImGuiLayer with new ImGuiLayer using ImGuiRenderer
Working through font texture creation and display size calculations
Debugging coordinate system issues (upside-down rendering)
2:26:00 First Success! 🎉
MAJOR MILESTONE: First frame renders successfully with new backend!
ImGui interface appears but with flickering issues and coordinate problems
Fixes Y-coordinate flipping in shaders to correct upside-down rendering
Interface becomes functional - can click buttons and see updates
2:39:00 Performance Investigation
Discovers serious performance issue: 30fps instead of expected ~144fps
Uses profiling tools (Visual Studio profiler, Tracy, RenderDoc) to investigate
Traces issue to VSync causing 30ms frame times
Discovers application was accidentally calling render twice per frame!
3:20:00 Final Debugging & Wrap-up
Fixes double-rendering issue caused by duplicate animate/render/present calls
Performance improves dramatically after removing redundant rendering
Some remaining issues with VSync behavior and color rendering
Stream ends with working ImGui interface running on new NVRHI backend