Draw Things Upscaler

"Upscaler" sounds like it should be complicated, but this node is a two-widget deal: pick an upscaler model, pick a scale factor, wire UPSCALER into the sampler's upscaler input. The server runs the upscale as part of the generation request, and you get a bigger image out of the sampler's IMAGE output.

It's the "more pixels" job, not the "more detail" job, in the upscaling taxonomy the community keeps tripping over: ESRGAN-style models like the ones Draw Things bundles add no new content - they enlarge what's there, fast and without hallucinating. If you want a model to invent detail (a generative pass), that's a different tool; this node is the clean 2x or 4x enlargement. The upscaler runs inside Draw Things, so again: the files live on the Draw Things side, selected from its model browser.

And yes - this pack is deprecated. The README's opening line tells you to uninstall and switch to the official draw-things-comfyui extension. The node still works.

How it works

add_to_pipeline packages the model and scale factor into a DT_UPSCALER bundle. The sampler includes it in the gRPC request, and Draw Things applies the upscaler when it decodes the result. If the server's model list doesn't advertise upscalers, the pack falls back to a built-in list of the standard RealESRGAN-family files - realesrgan_x2plus / x4plus, the anime 6B variant, and community standbys like Remacri and 4x-UltraSharp - so those names show up even on servers that don't report them.

The inputs that matter

• upscaler_model - the dropdown of upscalers from the Draw Things server. realesrgan_x2plus is the workhorse; the anime variant for illustration; 4x_ultrasharp / remacri if you want the community-favorite sharpening profiles.
• upscaler_scale_factor - 2 or 4, default 2. 2x is a safe default; 4x from a 512px base gives you 2048px, which is a lot of pixels to ask a denoiser to hold. If the sampler also has high_res_fix on, that's a separate two-pass feature - the upscaler and hires fix are different mechanisms, and you generally use one or the other, not both at full strength.

Installing it

ComfyUI Manager (search ComfyUI-DrawThings-gRPC) or:

cd ComfyUI/custom_nodes
git clone https://github.com/Jokimbe/ComfyUI-DrawThings-gRPC

Restart ComfyUI. Server side: Draw Things app with API Server on, gRPC, TLS enabled, Model Browser enabled, Response Compression disabled (or gRPCServerCLI --no-response-compression --model-browser).

Troubleshooting

The usual complaints are "no upscalers in the dropdown" (Model Browser off, or the server doesn't report its upscaler list - the fallback list should still cover you) and "the upscale looks soft" (you're at 4x from a small source, where every pixel upscaler runs out of information; 2x then a second pass, or an ESRGAN with a sharper profile, behaves better). And the wiring gotcha: the UPSCALER output must actually be connected to the sampler's upscaler input - it's optional there, so it's easy to leave dangling and quietly render at base resolution.