BAT4Blender

[Jasoncw 11,840]

BAT4Max uses the "sun" light, which changes the color of the sun automatically based on the angle of the sun. So if the angle is low, it's more orange, and if the angle is high, it's more white, and if you animate the path of the sun, it will automatically make a realistic sunrise and sunset. With BATing, the sun angle is fixed, and so the color of the sun is whatever it automatically is at that angle. It might be possible to learn what it is, but I think it's something that just needs to be matched visually with the preview renders. 

I tried to find my previous BAT4Blender work, and I didn't know where I put it, so I spent a few hours yesterday going through and sorting and organizing files on my computer, which was long overdue. Most stuff on my computer is pretty well organized, but the random stray stuff that doesn't have a place gets dumped into temporary folders, which then get dumped into other temporary folders. Anyway I've found what I had worked on and I'm reacquainting myself with it. 

[atsf189 460]

On 6/17/2025 at 5:04 AM, Koonam said:

light and shadows are not correct...?

This is what I used for lighting on my airplane models.

I am by no means an expert on this subject. They just looked good in the game.

[Koonam 519]

On 2025. 6. 18. at 12:13 AM, Fargo said:

By default the camera is set too low for very tall models. Go into the object properties of the b4b_cam and under delta transform you can change the location of the camera by height Z. Increase it until the camera object clears the top of your model. In the case of my model of 311 Wacker 80m was sufficient.

As for the shadows, go into the render settings and under the film tab, find exposure. It's set to 1 by default which causes sun-facing objects to appear washed out and shadows to appear almost pitch black. I think .5 or a little less is good for day scenes. Also make sure you are using the Cycles render, not Eevee.

Thank you so much! I changed render setting to Cycles render and set the sunlight color. But the shadow part is too dark yet. I saw that someone set the sky in Blender...? But I don't know how to make them in Blender. Maybe sky can make the shadows little bit brighter?

Sorry that I bring only tons of questions. 😂 I really hope BAT4Blender project will be completed someday!

[atsf189 460]

15 hours ago, Koonam said:

But the shadow part is too dark yet

I had the opposite problem. The white was getting washed out. 

I switched to a lightbulb type source so in was dimmer.

By selecting the light source you can move it around. try raising the sun above the building more.

These were my shadow settings

[Koonam 519]

I add the sky and edited the sunlight in Blender (This thread helped me to setting sky value and sunlight value. Thank you!). But there is no night preview tools in BAT4Blender, so I tried to make it looks like night view. I don't know if anyone has already tried it, and I'm not a Blender expert. but I'm writing it down in case it helps. I turned off the camera icon button of 'b4b_sun' in object list and set the emission color(white(1.0 , 1.0 , 1.0)) on the window glass object. The night view looks similar to that of Gmax render, except that darker shadows do not exist.

[Jasoncw 11,840]

I'm posting this mainly to write it down since there are so many little bits to everything. 

The sun has a property called "angle" which is the "angular diameter of the sun as seen from earth". In other words, it's how big the sun disc is in the sky. By default this is 0.526. BAT4Max uses 2.0. This is responsible for the shadows getting fluffier and fluffier as they get further away from the object casting them. 

[memo 1,439]

On 6/16/2025 at 9:43 PM, kaimai said:

Blender 4.4.1, Mac OS 11.7.6. From my memory, I think exporting worked on Blender 4.3.x so I'll try downgrading back to that for comparison.

 

edit: No, same error ("cannot open file") in 4.3. Everything still works in 4.2 though.

@kaimai I've tried to replicate this problem, but can't – using Blender 4.4.3 on Linux.

Usually, that error message would suggest a file access problem, external to Blender. For example, another process might block access to the file '5ad0e817_8bc0876f_00030000.obj' if it's opened in another program. Rebooting may resolve that. Or Blender is executed in a working directory for which it doesn't have "write" access. Adjusting the directory permissions, or running Blender from a different directory such as a subfolder in your home directory, may help.

[watercitymadero 804]

Hi, unexpert question here

I would love to learn how to BAT as well.

I'd like to know if I can create the models with Blender and export them to Gmax, then apply the textures and render the night there?
 

[memo 1,439]

I don't know about GMAX. Though, let me clarify that it's not impossible to do nightlights with Blender. Currently, BAT4Blender doesn't come with pre-configured nightlights (neither with pre-configured daylights, for that matter). However, you can adjust the light settings yourself to match a night time setting. There's just no preset.

Then you'd render the model twice (once for day and once for night). Then merge the two SC4Model files, adding an offset to the night textures.

If someone takes the time to find good nightlight settings that match the game, we can set those as default for everyone in BAT4Blender.

[City4fanatictasia91 17]

Hello sir @memo I'd sent you DM message

[kaimai 1,041]

On 7/6/2025 at 8:43 AM, memo said:

@kaimai I've tried to replicate this problem, but can't – using Blender 4.4.3 on Linux.

Usually, that error message would suggest a file access problem, external to Blender. For example, another process might block access to the file '5ad0e817_8bc0876f_00030000.obj' if it's opened in another program. Rebooting may resolve that. Or Blender is executed in a working directory for which it doesn't have "write" access. Adjusting the directory permissions, or running Blender from a different directory such as a subfolder in your home directory, may help.

Sorry for not replying to this earlier—I did restart and was able to render models again, so yes I guess it was one of those problems that originate between keyboard and chair.

One more question (which may be another one of those issues): whenever I manually change the camera location so that it shows the entire model, it resets automatically whenever I try to preview or render the .sc4model file. Not sure what I'm doing wrong.

[memo 1,439]

15 hours ago, kaimai said:

One more question (which may be another one of those issues): whenever I manually change the camera location so that it shows the entire model, it resets automatically whenever I try to preview or render the .sc4model file. Not sure what I'm doing wrong.

Indeed, there seems to be a problem for large models. When rendering, the camera is automatically positioned such that the LOD fits into the camera view, but if the model is large, it can intersect with the camera canvas plane so that you see only the part of the LOD that's in front of the camera.

For now, the simplest workaround is to increase the camera_range in the source code to something sufficiently large, such as 1000 meters.

[Fargo 542]

On 6/17/2025 at 10:13 AM, Fargo said:

By default the camera is set too low for very tall models. Go into the object properties of the b4b_cam and under delta transform you can change the location of the camera by height Z. Increase it until the camera object clears the top of your model. In the case of my model of 311 Wacker 80m was sufficient.

As for the shadows, go into the render settings and under the film tab, find exposure. It's set to 1 by default which causes sun-facing objects to appear washed out and shadows to appear almost pitch black. I think .5 or a little less is good for day scenes. Also make sure you are using the Cycles render, not Eevee.

@kaimai Did you already try doing this?

[kaimai 1,041]

9 minutes ago, Fargo said:

@kaimai Did you already try doing this?

That's what I tried initially yes, but with a ~485m model it always seemed to cut off either the top or the bottom. I'll go with memo's workaround for now but will double check after a restart/update.

[memo 1,439]

I had also tried Fargo's suggestion, but it didn't seem to work for me. Instead, I've now implemented a proper fix for the problem, so the camera now always gets positioned far enough away from the LOD, even if the LOD is large.

[kaimai 1,041]

This works, thanks!

The renders do appear unusually pixelated at zoom 5, to the point where I'm wondering if there's any chance that the renders are somehow coming out at half the resolution they're supposed to (the zoom 5 preview window in Blender also always seems to be half the expected size) but that might also just be my monitor/resolution/graphics settings. (It will also not have nearly as much of this problem once it's not an untextured box and I've figured out how to set Barocco Hispano's anti-bleeding background.)

Spoiler

 

[memo 1,439]

@kaimai By "pixelated", do you mean blurriness or aliasing effects? Did you render the model in SD or HD? If you render in HD, it's normal that you lose quality in zoom 5 in return for better zoom 6 quality, so it usually only makes sense to render small props in HD, but not entire buildings. With the HD option, the zoom 5 texture is rendered at twice the usual size, so that zoom 6 (using the zoom 5 texture magnified by factor 2) doesn't appear pixelated. However that means the game needs to downscale the zoom 5 texture in zoom 5 which degrades quality in zoom 5.

If the zoom 5 preview window in Blender had half the expected size, it would be the same as the zoom 4 render – which is not the case, on my end.

[kaimai 1,041]

@memo after reviewing this thread and Fargo's, I feel like this is probably the blurriness/aliasing issue from pixel filtering that @Fargo and @Jasoncw have alluded to as well. Alternatively might be an issue with my rendering settings. I tried rendering the same model in HD and the zoom 5 render seemed sharper as well, so maybe that's the way to go.

Spoiler

In standard def zoom 6, the image on the left is the standard Blackman-Harris pixel filter and the one on the right is the unfiltered (i.e., Box) filter. The unfiltered one has some aliasing issues, but seems to preserve detail better than the ostensibly antialiased filter one. I may also try exporting a version from BAT4Max to check the difference.

  Edited July 22, 2025 by kaimai  

[memo 1,439]

@kaimai Regarding the pixel filter, although BAT4Max seems to use Lanczos filtering, I think one of the main reasons that Lanczos is not an option for the Cycles renderer is that the Lanczos kernel has negative values, so it's not a probability distribution and doesn't allow drawing samples from the distribution.

What you suggest (rendering in HD, i.e. at twice the resolution, and then downscaling to half the size) is called supersampling and is a valid strategy for reducing blurriness and improving render quality. When you show an HD BAT in zoom 5, the game downscales the image using nearest neighbor interpolation (in case of BATs). I think we shouldn't rely on the game to do the downscaling on the fly, but it would be preferable to do the downscaling beforehand as part of the render post-processing. That way, it's not limited to zoom 5. It would also allow us to use Lanczos for interpolation. As Lanczos is particularly good at preserving edges (though, primarily for upscaling), that may lead to a sharper image.

To test how effective this is, try the following:

• Render a zoom 5 SD preview image of the building.
• Render a zoom 5 HD preview image. (For this, you can reduce the maximum number of samples by up to a factor of 4, to keep the rendering time short. Nevertheless, it will require more memory than the SD rendering.)
• Downscale the HD preview image to half the size using an image editing program. Use either Lanczos or Cubic interpolation.
• Compare the two images.

Perhaps @Fargo and @Jasoncw might be interested in this as well.

If this improves results, this could be implemented in BAT4Blender for every zoom level.

One more remark: Using a model with large flat untextured areas may not be quite conclusive, as it limits all the preservable details to the edges of the model.
 

[memo 1,439]

Playing around with Blender a bit more, I've started to look into animated props. This post summarizes some of my findings.

There are at least three different forms of animation in the game:

• ATC/AVP files: These are mostly used for animated people, but also for the default railroad crossing signals and traffic lights. They're either props or sprites. They don't have any 3D information, but are completely flat 2D images consisting of a series of frames. The frames are densely packed into a single 256×256 FSH file. It can be a multi-FSH if a single 256×256 plane is not enough, but each frame is limited to 256×256 pixels in size – and usually should be much smaller to keep the FSH file small. The frames are not necessarily aligned to the 4×4 DXT compression blocks, which can lead to artifacts.
• Effect Directory file: These animations are used in many different contexts, such as smoke, steam, sparkling effects, disasters, fauna, anything where a 3D model (other than automata) moves freely across the map, etc. From what I understand, they're attached to an S3D using the REGP section. I haven't looked into this at all so far, but this is the approach Xannepan has used for his mods.
• animated S3D files: Although almost always used for static models, the S3D format also allows for animations, as indicated by the "frame count" and "frame rate" setting in the Reader. Maxis has used these for the state fair animations, for some vehicle headlights, and for graffiti spraying animations, among others. Jondor has used these for his railroad crossing signals. Animated S3Ds are mainly useful for animating movement as a series of frames, especially when the materials stay the same for each frame. For example, the graffitis animate the X,Y,Z,U,V coordinates to enlarge the model from a point to a rectangle.

To turn a prop into an animated prop requires setting the property kSC4BuildingModelClassProperty (0xEA123CEF) (see also) to

• 0xAA123BF9 for ATC/AVP files, or
• 0xEA123BE1 for animated S3D files.

(I've tried using 0xAA123BF9 instead for an RKT1 S3D, but the result is that the model is only correctly oriented for the South view, and unexpectedly all zooms use the same Z5 model.)

When using RKT4, (tentatively) the property is an array that maps each state to whether it is animated or not. For instance, the following has four states where states 0, 1 and 3 are animated, but state 2 isn't: 0, 0xEA123BE1, 1, 0xEA123BE1, 2, 0x00000000, 3, 0xEA123BE1. For example, this is used for turning off an animation at night.

----

Although not used by Maxis, it's possible to animate an S3D by providing a unique material for each frame. I've used this approach to create this proof-of-concept for an animated fountain prop. It consists of 6 frames, each rendered in HD and exported separately using BAT4Blender.

(see attachment fountain-03.mp4 for a better quality recording)

I don't know the limits of this approach yet. In several cases, the model inexplicably didn't show up at all, for some reason – e.g. using FSH format A1R5G5B5 didn't seem to work, but A8R8G8B8 does. One would need to be cautious about not using too many resources.

One drawback of animations are the shadows. I haven't found a way to let other buildings cast their shadow onto the animated prop. Instead, the shadow masks out the animation:

It does work if the prop is not animated, so maybe this could be somewhat mitigated by placing a 2nd, static flat prop underneath.

If I raise the prop a bit, the model correctly displays on top of the shadow – that's the same as any other BAT.

However, the animated S3D also doesn't seem to cast a shadow itself (see also). It's not needed here, but maybe it could be mitigated by placing a 2nd, invisible static prop for the shadow.

----

As my model has a lot of detail, I see similar blurriness issues as have been observed by others already – especially in the more distant zooms. I haven't really played with the render settings yet and just used Blackman-Harris for the pixel filter. I still need to try the alternatives.

Z5 HD:  Z5 SD:  Z4:  Z3: 

The goal should be that Z5 SD looks at least as good as Z5 HD at zoom 5 in the game – which currently doesn't seem to be the case. Though, it might also be a result of DXT compression.

[memo 1,439]

I've started to explore the super-sampling idea outlined two posts above. This is going to be a long one.

TL;DR: The super-sampling works in that it gives sharper and more detailed renderings, for the same number of samples. The choice of down-sampling algorithm has a direct effect on the quality of the resulting final image. (Good choices are MagicKernelSharp2021 and CatRom filters).

----

First off, the default Pixel Filter in Blender is set to Blackman-Harris with a 1.5 px radius, which tends to be a bit blurry. By reducing the radius to a value between 1.0 px and 1.5 px, sharpness can be increased significantly. Some details may get lost though. The alternative Pixel Filter Box is not as blurry, but also loses some details.

By rendering at twice the resolution, the resulting image can be more detailed, even after down-sampling to the original resolution later on.

I've tested different combinations of rendering settings and down-sampling algorithms:

• Pixel Filter: Blackman-Harris 1.5 px ("pf-BH"), Box ("pf-Box")
• sample count: 512 for the original rendering, 128 for the super-sampled rendering at twice the resolution (so in total the number of samples per area stayed the same)

 

Down-sampling algorithms

In white, the two ordinary renderings at 512 samples (scaled up by factor 2 to see the details). These are the renderings we want to beat.

In green, for comparison, two renderings at twice the resolution, at 128 samples. This is the ground truth before down-sampling. (Obviously, at twice the resolution, these expose much more detail, for example in the light patterns in the water. Also, Box has noticeably fewer details than Blackman-Harris, e.g. in the bottom left of the pool.)

In yellow, the down-sampled images (scaled up by factor 2 again), ordered roughly from sharp to blurry. The sharper ones tend to have more aliasing or ringing artifacts. For all of these, I've taken Gamma correction into account.

The first one, Point (aka nearest-neighbor) is what the game uses to display a HD-rendered model at zoom 5 (because it's very fast to compute). I included it for comparison, as a good down-sampling algorithm should be better than that.

CatRomEWA (polar Catmull-Rom), a very very sharp filter, leads to high-contrast edges and strong artifacts, so basically useless. (Though, perhaps it could be useful for creating sharp 44×44 icons or maybe for Zoom 1 to 3 renderings of very small models.)

Lanczos (3-lobe) is the most popular choice for down-sampling. It's very sharp, but produces some ringing artifacts. Blackman is very similar, but has slightly less ringing. MagicKernelSharp2021 is very similar as well and has even less ringing due to some good theoretical properties. It's very new and gaining in popularity.

The EWA methods are particularly suited for rounded shapes like the hoop, but for typical BATs at SC4 viewing angles, the non-EWA (tensor) methods are more suitable, especially for vertical and horizontal lines or patterns. I've also found that the EWA methods widen the semi-transparent edge of the rendering by about 1 pixel, which seems undesirable to me.

CatRom is a very good candidate as well. Much less artifacts while still quite sharp (but less sharp than the previous filters).

The remaining filters like Box, Gaussian and the default Cubic are all way to blurry to be useful.

 

Sample counts

Here's a comparison of Blackman-Harris (top) vs Box (bottom) as Pixel Filter.

I've included super-sampled renderings at 128 samples and 512 samples. The latter obviously requires more rendering time, but also finds more details in the water. As mentioned before, the light pattern is less detailed in the Box rendering, so I have a slight preference towards using the Blender default Blackman-Harris over Box as Pixel Filter. Though, either setting produces very similar results with the super-sampling approach.

Next, here's a zoom 3 rendering showing the different methods. As the rendered image is tiny, I've also tried super-sampling not only at twice the resolution, but four-times the resolution (purple, cyan), which makes the result slightly sharper. What's obvious though is that all the super-sampled images are better than the ordinary renderings (white) in which the shadow is barely visible.

 

DXT compression

BATs are typically compressed with DXT1 compression, as displayed in the following images. This adds another layer of artifacts, making the images grainier, but the choice of a good down-sampling filter still has an effect.

 

A real example

To get a better idea how the different filters perform on typical BATs, I've applied them to an image of Fargo's recently released 20 N Clark building.

I've enlarged a few key areas:

The first column, Point, is a good example for why a skyscraper should not be rendered in HD. The moiré pattern completely changes the number of windows, here.

CatRomEWA has very strong ringing artifacts at lines with high contrast. This suggests where to look for these artifacts in the other columns, e.g. the edges of the walls on the roof, the dark edges of the windows, or the halo of the street light. With Lanczos, these artifacts are also quite visible. With Blackman, they're slightly less pronounced, and MagicKernelSharp2021 is a bit better still. CatRom has hardly any artifacts, but is a bit less sharp.

For me that's the sweet spot. Either MagicKernelSharp2021 or CatRom. I've attached all the individual test images (supersampling-test-images.7z), including the script I used to generate them, as it's much easier to compare two images back-to-back that way. Let me know your thoughts.

The next goal would be to implement this approach in BAT4Blender.

[Koonam 519]

Hello, I haven't been able to do activities because I've been busy with my real life. Finally, I got some times now and I'm editting the blender BAT now.

And I wonder that And I'm wondering how the other BAT makers who use BAT4Blender did the grid & Light settings. I also searched for the Blender tutorial and set up the grid, but weirdly, when I render it, the building somehow looks small or big. (The BAT screenshot I showed in this thread last time doesn't seem to match the size of the SimCity4 building.) 

Lastly, I'm also wonder about other BAT makers' day and night lighting settings. I can model the building, but I'm really bad at dealing with system settings and lighting. Actually, I barely understand the lighting theory of 3D programs. I think that's really difficult for me.   I've seen other people's threads and set the lighting before, but it's a little bit different from SimCity4's lighting...

[Barroco Hispano 26,671]

@memo CatRomEWA, Lanczos & MagicKernelSharp look great!

Does that mean it is possible to add Lanczos to Blender?

I use 64x64 samples  (Default 1x16) for very small props in 3dsmax and thanks to the modified @Null 45 FSHWrite, the z5 fsh's are inserted without compression preserving maximum quality (I know this is unrelated, but I wanted to point it out. It's good to know that in the future I'll be able to move all my files to Blender). 

On 4/8/2025 at 6:14 AM, memo said:

One drawback of animations are the shadows. I haven't found a way to let other buildings cast their shadow onto the animated prop. Instead, the shadow masks out the animation:

That happens when you activate the alpha blend at 100% (So to speak). Leaving everything untouched and changing the Alpha Func from "Always" to "Greater" should fix the problem. There is currently a way to enable 70% transparency for a BAT without any visual glitches, but it involves re-exporting the model twice and using a maximum transparency of 0.7 for the material. I can make a short tutorial if needed (the last two bus stations I added to my streets DLC use this technique).

However, if the model does not require transparency, it is best to leave it with the default parameters:

Everything you're doing is quite promising! I have a decent amount of rigged "Sims" so I can replace all the animated Maxis Sims with smaller ones.

I forgot to ask: Is there a huge difference in rendering time between those 3 super sampling methods?

[memo 1,439]

I'm happy to say that Super-Sampling is now implemented in BAT4Blender. The updated code is on GitHub.

This introduces a new external dependency ImageMagick, a cross-platform image command-line tool.

I've also updated the Readme, fixed some bugs (e.g. broken LODs when the BAT4Blender Collection was hidden from Viewport) and added an Advanced sub-panel for debug options.

On 8/10/2025 at 11:37 AM, Koonam said:

And I wonder that And I'm wondering how the other BAT makers who use BAT4Blender did the grid & Light settings. I also searched for the Blender tutorial and set up the grid, but weirdly, when I render it, the building somehow looks small or big.

@Koonam For the grid, Blender works with units in meters by default, with major grid lines set to 10 meters. The game also uses meters – each cell is 16 meters wide. This should help you fit the size of your model. For example, create a temporary base plane with the intended dimensions of your Lot. I've also found it convenient to set the Blender grid to 8 meters using the following setting, as then the grid lines fall onto the 16 m cell boundaries of SC4.

Edit: It's also common to scale buildings to 133% on the vertical axis to better fit with Maxis buildings and existing content.

As for the nightlights, I have the same question. It would be the next goal to implement a good default set of pre-configured nightlight settings.

On 8/10/2025 at 4:58 PM, Barroco Hispano said:

Does that mean it is possible to add Lanczos to Blender?

@Barroco Hispano Yes. The rendering process is a bit different than in 3dsmax, but the outcome is going to be similar. I'd recommend the newer MagicKernelSharp2021 over Lanczos though, as it's just as sharp but with fewer visible artifacts.

On 8/10/2025 at 4:58 PM, Barroco Hispano said:

I use 64x64 samples  (Default 1x16) for very small props in 3dsmax and thanks to the modified @Null 45 FSHWrite, the z5 fsh's are inserted without compression preserving maximum quality

For very small and detailed props, that's ok. Just I don't want to encourage this for larger models, as the uncompressed FSH files are much larger. FSH files already make up by far the largest chunk of the size of a typical Plugins folder and I wouldn't want to multiply this by a factor of 8 in general.

On 8/10/2025 at 4:58 PM, Barroco Hispano said:

That happens when you activate the alpha blend at 100% (So to speak). Leaving everything untouched and changing the Alpha Func from "Always" to "Greater" should fix the problem. 

I've tried again, but wasn't successful. Note that it does work if I turn the prop into a non-animated prop with the same mats settings, so I think this might be a limitation of animated models. Perhaps, the in-game shadows and the animations are drawn into the same buffer, so only one of them can be displayed by the game.

On 8/10/2025 at 4:58 PM, Barroco Hispano said:

I have a decent amount of rigged "Sims" so I can replace all the animated Maxis Sims with smaller ones.

That would certainly be a massive undertaking. There are so many Maxis Sims animations.

On 8/10/2025 at 4:58 PM, Barroco Hispano said:

I forgot to ask: Is there a huge difference in rendering time between those 3 super sampling methods?

No. The nice thing about this super-sampling method is that you can reduce the Max Samples to 25 % of your previous setting to keep the total number of samples identical. So CPU/GPU time stays more or less the same. Memory usage will be higher though (4×). The default settings in Blender use Max Samples 4096, but that number can be reduced quite a bit to save time without losing too much quality. In pratice, this value is going to be set depending on the model and the desired rendering quality. Regarding the down-sampling filters mentioned above, the final down-sampling step will only take a split second.

[Koonam 519]

15 hours ago, memo said:

 

@Koonam For the grid, Blender works with units in meters by default, with major grid lines set to 10 meters. The game also uses meters – each cell is 16 meters wide. This should help you fit the size of your model. For example, create a temporary base plane with the intended dimensions of your Lot. I've also found it convenient to set the Blender grid to 8 meters using the following setting, as then the grid lines fall onto the 16 m cell boundaries of SC4.

Edit: It's also common to scale buildings to 133% on the vertical axis to better fit with Maxis buildings and existing content.

Oh, Thank you for the sharing Memo! I'm so appreciate it.  

15 hours ago, memo said:

As for the nightlights, I have the same question. It would be the next goal to implement a good default set of pre-configured nightlight settings.

Sorry for the confusion. I was talking about the day and night sky settings.

And I hope you succeed in setting up the nitelite preset for BAT4Blender someday.🙏

[Jasoncw 11,840]

Wonderful progress! 

Blender has a built in, node based, compositor which might be able to do some things for us. It might be possible to use the compositor to adjust the alpha mask to make everything less than 30% transparent into 100% transparent. It might be possible to do this through the script as well (this is done in BAT4Max). If I understand correctly this and the settings in the .SC4Model file basically turn on antialiasing around the edges for BATs. For me personally I spend way too much time trying to minimize the halo around the edges of the BAT, and there are situations where I don't even do certain buildings or certain architectural features because I know it will cause a halo problem. And then even when there isn't a visible halo, having antialiased edges would improve the look of the game a lot imo. 

The supersampling is very promising. Since this is happening to the render after it's done, the only samples are the final pixels, which for BATs is going to be very low resolution details (so many details in BATing are only about a pixel big in zoom 5). Because of how few pixels there are in such a small area, there aren't many samples for it to work with. It might be worthwhile to explore having the renders be something really crazy, like 8 times bigger than normal, rather than just 2 times, so that there are more pixels/samples to work with. 

For the supersampling though I do have a concern (which might be unsolvable), which is for BATing workflow. Normally while BATing you do a lot of preview renders. A lot of the time you'll cancel the render part way through because it's finished the area that you're working on that you're judging. It's very fast and iterative, especially when you're newer and need to make more adjustments to make things look good. Not having wysiwyg preview renders would make BATing a lot harder. 

Also I did make a day lighting rig but I haven't shared it yet because I need to redo it with better light values. There aren't light units in the interface, but apparently under the hood it does use physical units. So I need to go through and change the light values to realistic values and then adjust the exposure. When I get around to that I can share it and people can provide feedback. 

[memo 1,439]

16 hours ago, Jasoncw said:

Blender has a built in, node based, compositor which might be able to do some things for us. It might be possible to use the compositor to adjust the alpha mask to make everything less than 30% transparent into 100% transparent. It might be possible to do this through the script as well (this is done in BAT4Max). If I understand correctly this and the settings in the .SC4Model file basically turn on antialiasing around the edges for BATs. For me personally I spend way too much time trying to minimize the halo around the edges of the BAT, and there are situations where I don't even do certain buildings or certain architectural features because I know it will cause a halo problem. And then even when there isn't a visible halo, having antialiased edges would improve the look of the game a lot imo. 

By default, BATs use FSH files that are compressed with DXT1. DXT1 files have a single bit alpha channel, so each pixel is either fully transparent or fully opaque. When using fshgen to create the FSH files, everything less than 50% transparent (alpha 0-127) is set to 0 (fully transparent).

Having semi-transparent edges is possible by using DXT3-compressed FSHs instead. These FSH files are twice as large as DXT1 files, as they use the same amount of bits for the alpha channel as for all colors combined. Another drawback is that this requires enabling framebuffer blending in the S3D material settings, which is less efficient to draw for the game. So it's best to find a balance here and use these settings when it makes sense, such as for semi-transparent bus stops or train stations. Personally, I've never payed much attention to the aliased edges of BATs, as they tend to blend in with other BATs in the background, but as BATting has never been my primary modding focus, I may have just valued other details more.

Also note that the Lanczos (3-lobe) filter is responsible for a visible halo around the edges. For example:

Here, I've set alpha 1-255 to opaque and 0 to black. The halo should usually be below 50% alpha, so it shouldn't be visible in the game. In contrast, the CatRom filter does not have this halo problem at all.

17 hours ago, Jasoncw said:

The supersampling is very promising. Since this is happening to the render after it's done, the only samples are the final pixels, which for BATs is going to be very low resolution details (so many details in BATing are only about a pixel big in zoom 5). Because of how few pixels there are in such a small area, there aren't many samples for it to work with. It might be worthwhile to explore having the renders be something really crazy, like 8 times bigger than normal, rather than just 2 times, so that there are more pixels/samples to work with. 

Yeah, so in my post above about the down-sampling filters, I did try a super-sampling factor of 4 for the Zoom 3 images. Results are a bit better than with factor 2, but it also used a lot more samples, so this might have diminishing returns. When some details become too small, it's a lost cause. My impression was this might be more useful for Zooms 1 to 3, where using more samples is more affordable due to the smaller size and where it's clear that details are present in the model that might not otherwise be visible in the render.

An optimization could potentially be implemented for Zoom 4. As Zoom 4 uses the same camera angle as Zoom 5, one could simply down-sample the Zoom 5 renderings to get a super-sampling factor of 4 for free (or 8 in case of HD models).

17 hours ago, Jasoncw said:

For the supersampling though I do have a concern (which might be unsolvable), which is for BATing workflow. Normally while BATing you do a lot of preview renders. A lot of the time you'll cancel the render part way through because it's finished the area that you're working on that you're judging. It's very fast and iterative, especially when you're newer and need to make more adjustments to make things look good.

I do get the concern. My naive expectation is that a typical workflow would use 1× resolution (no super-sampling) most of the time and only turn on super-sampling when it's relevant to see those differences, i.e. an increase in sharpness. Currently, this requires a full preview render, but you can turn down the Max Samples of course.

I also expect that, for faster iteration, one would set a small render region (CTRL+B) to render only the area of interest. This currently doesn't work with the BAT4Blender Preview and Down-sample buttons (it could be implemented though), but works fine with ordinary renders (F12) once the camera is positioned for the zoom and rotation.

When you cancel a render part way through, the image doesn't look like the final render either way, as the Denoising step isn't executed, so it's not just the Super-Sampling/Down-Sampling step that's missing. Blender makes it very difficult to access the image of an aborted render process, so there's probably not much that BAT4Blender could do here.

[kaimai 1,041]

On 8/12/2025 at 3:00 PM, Jasoncw said:

For the supersampling though I do have a concern (which might be unsolvable), which is for BATing workflow. Normally while BATing you do a lot of preview renders. A lot of the time you'll cancel the render part way through because it's finished the area that you're working on that you're judging. It's very fast and iterative, especially when you're newer and need to make more adjustments to make things look good. Not having wysiwyg preview renders would make BATing a lot harder. 

Semi unrelated, but this is one of the reasons I do prefer Blender to 3DSMax at the moment—in 3DSMax I basically can't cancel a preview render partway through, the program will freeze if I do that (for approximately as long as it would have taken to complete the entire preview render), and it also takes several minutes for the textures to fully load during the preview. In Blender I'll have a better idea of what the textures look like within a minute or less and can cancel the preview render immediately without the program freezing. But yes as a workflow thing this is sufficiently time-saving as to basically negate all the other advantages of BAT4Max.

Anyway: will install ImageMagick and the update and see what happens once I have some textured models.

[Barroco Hispano 26,671]

On 11/8/2025 at 3:25 PM, memo said:

Just I don't want to encourage this for larger models

Yep, I only use it on very small props. I've occasionally had to re-export buildings because I forget to change the script, and they end up with a large size . PIM-X also doesn't get along very well with uncompressed FSH, it gives them a very strange color.

On 11/8/2025 at 3:25 PM, memo said:

I've tried again, but wasn't successful. Note that it does work if I turn the prop into a non-animated prop with the same mats settings, so I think this might be a limitation of animated models. Perhaps, the in-game shadows and the animations are drawn into the same buffer, so only one of them can be displayed by the game.

On 10/8/2025 at 9:58 AM, Barroco Hispano said:

It's quite strange because it should also happen with the maxis animated props .

I enabled transparency for the ship wake with the SC4 Model Tweaker. It works pretty well in the water, but on land the shadowed part disappears (which isn't a problem for me since it's meant to be placed in the water anyway).

On 11/8/2025 at 3:25 PM, memo said:

That would certainly be a massive undertaking. There are so many Maxis Sims animations.

On 10/8/2025 at 9:58 AM, Barroco Hispano said:

The most important thing is to have the 3D models, mixamo will do the rest 

 

 

 

[kaimai 1,041]

Ran into a minor issue: super-sampling seems to require Blender 4.4+, since I get an error when attempting to update the add-on in 4.3. Blender 4.4+ requires Mac OS 13.3+ (otherwise BAT4Blender returns error "Symbol not found: _cblas_caxpy$NEWLAPACK" on render) which I don't currently have access to; this will apparently be fixed in 4.5 but developers haven't done so yet. So I can't test this myself at the moment, but hopefully someone else can.