Bringing Static 3D -Archviz People to Life with AI Video

Introduction

When you first see AI video demos, your brain does something funny. It takes the 75% you're seeing and draws a straight line to 100%: everything is possible, we're all doomed.

Then you actually sit down with the tools, and you learn to be careful with your assumptions. That gap between the demo and the deliverable is what this tutorial is about. Bringing static 3D people in your archviz render to life with AI video works, and sometimes it's even easy.

The gap between 'easy' and 'exactly what you wanted' is just a fair amount of work. Pick your starting point below.

SUBSCRIBE
And receive a free model

Choose your route

Everyone reads differently, so feel free to jump:
→ I just want a quick, good-looking result
→ I want full control over who does what
→ First things first: which AI tool should I use?
→ Tell me everything, I'm reading A to Z. (Just keep scrolling, this one's for you.)

1. The playing field

At the time of writing (July 2026) I gave Veo 3.1, Grok, Kling 3.0, Seedance 2.0 and a few others the same simple request: keep the camera still and only move the people. Nearly all of them acted like they hadn't heard me.

My original idea was to render two versions of every scene: a clean backplate and one with 3D people in it. Animate the people with video AI, then comp them back over the clean plate, keeping the architecture untouched. Spoiler: this is roughly where I ended up, but the road there taught me three things.

1. Video AI changes your original input far less than I assumed.
2. Video AI is expensive!
3. Video AI does not, I repeat, does not want to keep the camera absolutely fixed without some serious prompting.

That third issue is why I landed on Seedance 2.0. It wasn't the cheapest model I tested, but it was the only one that kept the camera locked with any degree of reliability.

A quick note on the different flavours you'll encounter: text to video, video to video, video upscaling, and the one we're using here: image to video. Whatever platform you choose, the workflow is similar. Upload an input image, write a prompt, and set your duration, resolution and whether you want generated sound.

Make sure your input image (your render) matches an aspect ratio the video AI supports. I went with 16:9. My input was 4K because I need that resolution later, but keep in mind that most video AIs max out at 1080p. If a platform advertises 4K output, that's usually a built-in upscale feature, not native 4K generation.

For the record: I ended up using atlascloud.ai for video generation and gigapixelai.com for upscaling. Atlascloud can go straight to 4K, but doing the upscale at Gigapixel turned out to be considerably cheaper.

What does it cost?

Compared to rigging and believably animating these characters, the cost is nothing and the result looks better. That is exactly why I wanted to write this tutorial: we are so close to getting awesome results at a fraction of the cost. But it's definitely not free.

A 15 second clip at 4K costs me about $16 to $18 at atlascloud.ai. The same clip at 1080p, without their upscaling, is about $6 to $8, which is why I chose to do the upscaling elsewhere. All this without any guarantee that the resulting video doesn't show something weird. The built-in solution seems to be generating 4 videos in one go. Sure, you pay 4 times as much, but the chance of getting a usable clip is greater.

Do your testing at lower resolutions ($1.60) or combine that with shorter lengths ($0.50 for 5 seconds).

Some of you may remember dial-up internet. I'm sure prices will drop in the future, but for now there are no all-you-can-eat AI plans for us!

2. The fast route

Sometimes good enough is simply good enough. Drop your render into Veo or Seedance, add a short prompt about what the camera is allowed to do, and odds are you'll get something usable. The AI turns out to be surprisingly gentle with your architecture.

Here it's mainly a game of learning what to write as a prompt. Negative prompts like "don't do this" or "avoid that" do not work all that well. Positive instructions for the camera look something like this:

"A subtle, believable handheld camera shot, the camera is held by a steady human hand with gentle, organic micro-movements and a slow, soft drift, natural and barely-there, as if someone is quietly standing in the room looking at the scene."

Then you can add what you want the people in your scene to do, like:

"The couple stands in place, chatting as if at a party. No walking."

Happy with the result? Then you're done, and this was a short tutorial. 

Want to make sure the woman in the red dress doesn't suddenly start dancing with her partner, or that the couple in the doorway doesn't walk backwards out of the room? Keep reading, because now it becomes work.

atlascloud001
How to make an AI video from an image at atlascloud.ai 
The result

3. The control route

This is where the frustration starts, but also the directing. Forget hunting for the perfect prompt. The real trick is breaking the problem apart: one person at a time, one video at a time, then bringing it all back together in After Effects.

Granted, the example scene I used (kindly provided by bbb3viz) might have more people in it than you would have in an animation for a typical client. If that's the case, everything that follows becomes easier. Having this many people in one scene really exposed the weakness of the fast route described above. Somehow there was always one person doing something unnatural.

Couple005
Couple004
Couple003
Couple001
The final result

Where to upscale

There are quite a few apps and sites to do the actual upscaling. Ive tested three of them:
All three do much more than upscaling so look for the 'Upscaling' section of each. 

They are all great fun to play with. They all come with 3 to 4 sliders to play with that pretty much do the same thing for all but can be labeled a bit different:
  • Creativity
  • Resemblance
  • HDR
  • Strength
On top of that there are dropdowns to select different styles like: Realism, Cinematic, Soft, High-HDR and more. 

Most come with some free tokens for you to play with when you sign up. And when you decide to buy tokens it gets you quite a lot of generations attempts. 

There is a lot of variables you can tweak, and I did so you do not have to.

Which to pick?

Honestly they are all pretty similar. You can get something useful out of any of them and they all hallucinate weird stuff at times or when you push the sliders to the extremes. Leonardo.ai is the only one that 'just' does a 2x scaleup but also this is not really a problem with some prepwork on your end.

Magnific.ai and Deepdream.com have a prompt field that can be useful to guide the generation a bit. For example, the upscalers seem to want to make mini adults from children. Entering a prompt like: 'the right person is a little girl' actually helped me. 
Magnific_AI
Leonardo_AI_88e83b63-9949-4309-9c7a-7328b8b81a3c
DeepDreamAI_9fb3bbe6-548e-41b5-a11b-8d5e8c88fd8c
DeepDreamInterface

Where to upscale

There are quite a few apps and sites to do the actual upscaling. Ive tested three of them:
All three do much more than upscaling so look for the 'Upscaling' section of each. 

They are all great fun to play with. They all come with 3 to 4 sliders to play with that pretty much do the same thing for all but can be labeled a bit different:
  • Creativity
  • Resemblance
  • HDR
  • Strength
On top of that there are dropdowns to select different styles like: Realism, Cinematic, Soft, High-HDR and more. 

Most come with some free tokens for you to play with when you sign up. And when you decide to buy tokens it gets you quite a lot of generations attempts. 

There is a lot of variables you can tweak, and I did so you do not have to.

Which to pick?

Honestly they are all pretty similar. You can get something useful out of any of them and they all hallucinate weird stuff at times or when you push the sliders to the extremes. Leonardo.ai is the only one that 'just' does a 2x scaleup but also this is not really a problem with some prepwork on your end.

Magnific.ai and Deepdream.com have a prompt field that can be useful to guide the generation a bit. For example, the upscalers seem to want to make mini adults from children. Entering a prompt like: 'the right person is a little girl' actually helped me. 
Magnific_AI
Leonardo_AI_88e83b63-9949-4309-9c7a-7328b8b81a3c
DeepDreamAI_9fb3bbe6-548e-41b5-a11b-8d5e8c88fd8c
DeepDreamInterface

Where to upscale

There are quite a few apps and sites to do the actual upscaling. Ive tested three of them:
All three do much more than upscaling so look for the 'Upscaling' section of each. 

They are all great fun to play with. They all come with 3 to 4 sliders to play with that pretty much do the same thing for all but can be labeled a bit different:
  • Creativity
  • Resemblance
  • HDR
  • Strength
On top of that there are dropdowns to select different styles like: Realism, Cinematic, Soft, High-HDR and more. 

Most come with some free tokens for you to play with when you sign up. And when you decide to buy tokens it gets you quite a lot of generations attempts. 

There is a lot of variables you can tweak, and I did so you do not have to.

Which to pick?

Honestly they are all pretty similar. You can get something useful out of any of them and they all hallucinate weird stuff at times or when you push the sliders to the extremes. Leonardo.ai is the only one that 'just' does a 2x scaleup but also this is not really a problem with some prepwork on your end.

Magnific.ai and Deepdream.com have a prompt field that can be useful to guide the generation a bit. For example, the upscalers seem to want to make mini adults from children. Entering a prompt like: 'the right person is a little girl' actually helped me. 
Magnific_AI
Leonardo_AI_88e83b63-9949-4309-9c7a-7328b8b81a3c
DeepDreamAI_9fb3bbe6-548e-41b5-a11b-8d5e8c88fd8c
DeepDreamInterface

Just drag and drop

The basic process is as simple as:
  1. Rendering your image
  2. Saving render
  3. Dragging render into Upscaler website
  4. Fiddle with settings
  5. Click upscale
  6. Download result

Limitations and how to work around them

This might be arcane magic but it cannot work wonders.

It seems when the upscaler does not have much to work with it starts to do funky things and this is most noticable with the people in the background. You can either not go trough the effort of applying upscaling to the background people or do the following...
Weirdness_Crop_before
No Upscale
Weirdness_Crop_after
With Upscale
Weirdness_Crop_after_trick
With fix applied
You might not might not want to upload crazy high res images to the upscaler websites. There might be limits and also the bigger the image the more credits you use. Also rendertime alone would be a nightmare. What works well is to render larger resolution crops of just the people. 

Then upscale those and paste them back in the original render while scaling them down to the correct size in your post processing software of choice. 

In the example to the right I used quite large crops however you can make as many as you want. possible one per 3D human.
Enlargement_Example
Rendering a larger resolution crop of just the people.
before-after-2
Before
After
before-after-1
Used 3D interior scene from the mighty Bertrand Benoit and 3D people from our very own Humanalloy.com collection

Layered approach

There are a few reasons you want to work in layers for your final composition. 
  1. You probably do not want to upscale everything in your image
  2. Some parts you might want to push the upscale a bit more
  3. Just to find the hands go haywire...always the hands
  4. Above mentioned background problems
In the video to the right you can see that the original upscale left the mothers hair very featureless. I had to go to the extremes in the upscalers 'realism' and 'similarities' sliders to get something I liked for the hair. The result for the rest of became something of a hairdressers worst nightmare. If you go beyond the mildest default settings of the upscalers the hands start become a nightmare on its own. And to top it off all the upscalers though the pink sweater of the little girl was skin and started adding horrific details...

All to say: apart from the mildest upscale settings, do expect to do some post work, such as adjusting the hands, fixing hair details, or blending the upscaled areas more seamlessly into the overall image.
Scary_Upscaler1
The..
Scary_Upscaler2
Horror...
Scary_Upscaler3
Make it stop...
before-after-2
Before
After
before-after-1

Experiment

I want to leave you with one last experiment. The guy in the back is one of my older rigged 3D human scans. I often find that rigged 3D scans often do not feel quite right. Often because they are scanned in an a-pose with the clothing forming to that pose. When you pose that model later something feels not quite right.

Upscaling partially solves that. Folds in the clothing seem to be more on point. The pose however feels just as bad as I created it. So spend more time on the pose than the clothing when using rigged 3D people when upscaling.

Also there are non-people parts that come out better when upscaling an image. Try experimenting with compositing those in as well where appropriate.
Street_Cutout_original
Street_Cutout_Upscaled

Conclusion

When adding upscaling to your post-processing pipeline it becomes far less important to purchase high resolution, more expensive and difficult to use 3D people.

Here you are in luck since it just so happens I have a 3D people store here selling some of the best and most affordable 3D people! Which become even more affordable if you buy them as sets or libraries .
Newsletter_Sig