How do you enhance an architectural render in ComfyUI without changing the design?
Translate each requested improvement into a permitted region, a structural control and a rejection test. Use depth or edge guidance for the whole frame, masks for local edits and conservative denoise for preservation. Compare the result with the source before upscaling, because “keep the composition” protects too little.
A familiar forum request asks for better lighting, textures, reflections and vegetation while maintaining the overall composition. Four changes, one reassurance. The reassurance is doing heroic and unpaid work.
Composition can remain stable while mullion spacing changes, a parapet grows and the glass acquires a fictional skyline. An enhancement brief needs architectural nouns, not soothing adjectives.
Why is “maintain the composition” too weak?
Composition usually means the camera and large masses stay recognizable. It says nothing about opening counts, slab edges, material boundaries, signage or the species and location of planting. Diffusion can preserve the silhouette and still redesign the building one plausible detail at a time.
The r/FluxAI request surfaced the real cluster of enhancement work: lighting, textures, reflections, vegetation, shadows and overall composition. Those are not one operation. Each has a different risk surface.
Our ComfyUI change-budget guide limits how much a pass may alter. A change contract goes one step further. It assigns every desired change a place, a control and a reason to reject the output.
What belongs in a change contract?
| Request | Permit | Protect and reject |
|---|---|---|
| Warmer dusk light | Sky, illumination and cast-light color | Reject shifted sun logic, erased fixtures or new openings |
| Richer facade material | Texture and controlled tonal variation inside facade mask | Reject moved joints, changed bay rhythm or false relief |
| Better glazing | Reflection character within glass mask | Reject invented context, opaque panes or lost mullions |
| More planting | Named ground and planter regions | Reject blocked entries, changed paths or impossible scale |
| Larger delivery | Resolution and recoverable surface detail | Reject tile seams, doubled edges or invented micro-detail |
Write the table before touching the sampler. It turns review from “this feels different” into a set of observable failures. That sounds less glamorous than a prompt, which is precisely why it survives a deadline.
ControlNet beats prompting for protected geometry
A prompt can describe the desired atmosphere. It cannot reliably enumerate every line that must remain. Use a depth map to hold broad spatial relationships and an edge control when thin architectural boundaries matter. If both are used, check that their maps agree. A noisy depth estimate and an aggressive edge map can pull the graph in different directions.
Control strength and denoise must match the contract. A low-change relighting pass should not use the same denoise as a concept restyle. The exact value depends on model, scheduler, resolution and source quality, so universal numbers are theatre. Run a small ladder, save the settings and stop when protected facts begin to move.
The depth and edge conflict guide explains how to inspect the maps before generation. If the control image has already merged two mullions, the output has been given permission to do the same.
Masks turn broad wishes into local work
“Improve materials” invites a whole-frame redraw. A facade mask makes the instruction smaller. Separate glass from opaque wall. Separate vegetation from paths. Feather enough to avoid a pasted edge, but keep the transition out of geometry that the edit is not allowed to touch.
Run global corrections before local repairs. Establish light and broad color while structure controls cover the complete frame. Then work inside masks for glass, planting or one damaged material. Reversing that order makes later global passes erase careful local work.
Our global-pass and local-repair workflow sets that order. The sequence is modest. Its reward is that a reviewer can identify which pass introduced a defect.
When should upscaling happen?
After the design and edit contract pass review. The PAACADEMY workflow list names upscaling as especially relevant to architectural renders. That is reasonable, but upscaling is not a neutral export switch. A generative upscale can sharpen a wrong mullion with magnificent conviction.
Approve the working-size image first. Record dimensions and compare it with the source using a difference view or rapid overlay. Then upscale and inspect at three scales: thumbnail for composition, fit-to-screen for repeated geometry and 100 percent for seams, text and material edges.
The three-scale 4K review provides the inspection pattern. Large output is delivery work, not permission to reopen the design.
How should the graph record the contract?
Put the contract beside the workflow JSON and name its revision. Record the source filename and dimensions, model, LoRAs, control preprocessors, strengths, denoise, sampler, seed, masks and output dimensions. Save an approved preview. A graph without its input and acceptance rules is machinery without a job description.
Use stage checkpoints. Keep the base image, global pass, each local repair and final upscale. When glazing becomes opaque, the team should be able to identify the responsible pass without rerunning the entire graph and hoping for a kinder seed.
ComfyUI's value is that the operation can be visible. Do not squander that visibility by naming nodes “final,” “final2” and “good one.”
ArchiGen's take: adjectives belong in the art direction
“Atmospheric,” “realistic” and “polished” can guide the image. They cannot protect a design. Protection comes from source evidence, control maps, masks and explicit rejection rules.
The forum request is right about the desired result. It simply asks one sentence to govern six kinds of change. Give each change its own boundary.
The graph can improvise inside the contract. The building stays out of reach.
Evidence note: the requested enhancement categories were checked on 25 October 2026 against the cited r/FluxAI thread and PAACADEMY's ComfyUI workflow article. Technical guidance is procedural, not a report of ArchiGen testing. No universal denoise or control value is claimed.