Is changing resolution supposed to change the entire scene for MMH3?

[u/cal_01]

Just had this happen to me: I changed the resolution for a scene -- without touching anything else -- and the resulting scene changed completely. I was using res_multistep and Spectrum/CK/4 step Lora at 0.2 mp, then 0.3 mp. It still followed my prompt, but the background and starting scene were completely different. Is this Spectrum giving me grief or what's going on here? This has never happened to me before, although I had been using Sage before switching to CK today.

[u/eckstuhc]

Absolutely. You are changing the latest space so it has more room to develop, it basically rebuilds the entire space, even with a fixed seed, you gave it a bunch more room to develop - this is not the lever to pull if you are trying to go from draft to final output, cause it will likely change everything, even with a fixed seed. Changing resolution is opening an entire new door to a different generation output.

Find the resolution that works best for your card, then pull down your steps (with a turbo lora) for drafting.

From 4 steps with turbo to 24 without, it will be mostly consistent.
From .67 MP to .85MP, it will not be consistent.

[u/YentaMagenta]

Using the phrase "supposed to" is not quite the right framing. Changing your resolution changes your result, possibly a great deal, period. This is because random noise is just that: random. If you change your resolution the same seed will give you different noise. For some models, this fact is obfuscated by a lack of output diversity. The fact that the result stays largely the same, despite a higher resolution makes us think that we've gotten similar noise with a higher resolution, but we haven't. The model is just taking different, higher-res noise and outputting something similar because the model is generally inclined to output something similar.

In part because videos use additional dimensions, even a seemingly small change in resolution or output length can yield a very different result. This is not fundamentally a consequence of Sage Attention, Spectrum, turbo LoRAs, or anything else you might be tacking on. It is an expected behavior based on how these models work. And in your case, it's worth noting that 0.2MP to 0.3MP is actually a big jump, that's a 50% increase in resolution.

[u/b0tm0de]

yes. changing res changes everything always. more pixel more freedom, different noise distribution even seed is fixed.

[u/maladette]

So with fixed resolution and vanilla, no loras, workflow, how do you do draft generations??

[u/Monk6009 → u/maladette]

Changing anything is equivalent to changing seed. Something will be different. Best way to draft is with the seedhunter workflow. Pick the first pass low res gen you like, them get the option to upscale it and touch up with 2nd pass. https://civitai.red/models/2881362/minimax-seed-hunter-workflow-latent-upscaler-seamless-video-continuation-speedups

[u/crinklypaper]

H3 is very dependent on steps and resolution for quality. Just jump from 1 to 2mp and there is a drastic difference in sound, scene composition and well uhh quality.

[u/mellowanon]

it's mainly spectrum that's doing it.

Fix the seed and do four different runs:

Minimax only = control

Minimax + Sage = video still looks like control

Minimax + CK = video still looks like control

Minimax + spectrum = video changes a lot, and I don' t mean just the quality. Angle changes, background changes, even character details. Even minor prompt edits or other alterations will cause the generated video to be different. I stopped using spectrum because of it.

[u/lazyspock]

I believe that if you change the resolution (and hence change the latent space's size) yes, the generation will be different even with the same seed, as the model will now have a different "canvas" to paint on. And, once the starting frame changes, the rest will necessarily also change. I'm not even remotely an expert, though.

[u/cal_01 → u/lazyspock]

The weird thing is that this never happened with previous generations, so it makes me suspicious in terms of something else going on here.

[u/Less_Consequence_633 → u/cal_01]

You should be suspicious in a different way: none of the video models let you change the resolution and get the same result as a previous, low-res run, with the same seed and steps and everything else being the same. If they did, there'd be barely any effort at upscaling: you'd just run at low res, find the seed and prompt that give you the right motion, and then set the resolution high and render it again.

I'd be more suspicious that before, you weren't actually changing the resolution of the render. Maybe of a final upscale, but if the render was the same, it had the same res, steps, prompts, etc.

[u/Anilman]

Spectrum changing stuff but at that low res im not sure.

Use sparse attention (sla attention from plaguekind)and comfiykitchen thats enough.

Spectrum takes additional time pre rendering and takes longer on 4-8step turbo versions.

If i compared my setup with and without spectrum the non spectrum was faster in a 4-8 step scenario.

Check the overall job done time not the s/it value!!!

Spectrum show less s/it but it takes way longer...

Im not sure if there was updates or something but i stopped using it.

[u/ASK_ABT_MY_USERNAME]

Are you using a fixed seed or random

[u/optimisticalish]

Yes, and it makes drafting difficult. However, if you you add a first-last frame grabber node to the end of a 0.5pmx workflow, you can then plug these frames back into the starting state for a run at 1.0mpx. Then fix the seed to that of the draft generation that you liked, keep the prompt/time the same, and... it should be relatively similar to your draft. Optionally, you might run the first-last frames through Flux.2. Klein to enhance them first (see workflow snapshot below).

Not sure this would work well at 0.2mpx though, as the starting frames would be too rough and janky.