Looking for some texturing tips: AO maps

[Ryno917 102]

Hey guys, looking for some workflow tips from the vehicle creation guys. I want to make a few vehicles for C:S. I can model the vehicles fine and blunder through UV mapping, but where I struggle is creating the AO map; the shadows and highlights on the texture to give the low poly model some more definition. I know some artists use photographs of the real car, manipulated, to give these details, but what do you guys do when that's not possible (no good photos, fictional content, etc)?

The only thing I can think of is to create a high poly version and bake an AO (and normal map) to use on the low poly car. Depending on the vehicle, that could be quite a bit of extra work. Do you guys have any extra workflows to achieve something?

[Avanya 2,605]

I haven't really done many vehicles, so I'm far from an expert, but I typically hand paint details or construct them from many images (like my own little Frankenstein's monster). For my volvo truck I straight up painted highlights on the texture in Blender (texture painting) and then applied them as a layer on my texture. I'll also often use effects like "drop shadow" or "glow" in Photoshop to fake some AO for little details. It works pretty decently since we work with fairly low resolutions for CS.

[Ryno917 102]

4 hours ago, Avanya said:

I haven't really done many vehicles, so I'm far from an expert, but I typically hand paint details or construct them from many images (like my own little Frankenstein's monster). For my volvo truck I straight up painted highlights on the texture in Blender (texture painting) and then applied them as a layer on my texture. I'll also often use effects like "drop shadow" or "glow" in Photoshop to fake some AO for little details. It works pretty decently since we work with fairly low resolutions for CS.

I was hoping you weren't going to say that LOL

I'm useless at hand-drawing that kind of shading. I might try to go with a mixture of high poly surfaces baked down onto the low poly model and hand-drawing other details (door handles, badges, etc) and seeing if that is a good compromise between quality and speed, unless someone else has some ideas

[Avanya 2,605]

You can probably grab some of that off images of similar car types. A chrome handle will look almost the same no matter the vehicle - at least when scaled down to the size of your texture. I recently did that with a door. Just grabbed a handle from a door, cut it out and scaled it for my door and it worked out much better than anything I could have done by hand. There's also the option of grabbing pictures yourself when you're out and around. If you have a phone with an alright camera, you can take pictures of cars you pass that has the details you're after, and again cut them out and apply them to your vehicle. Ofc how fast this will be compared to modelling the details depends on how comfortable you are messing around with images vs how fast you could model it.

[Ryno917 102]

2 hours ago, Avanya said:

You can probably grab some of that off images of similar car types. A chrome handle will look almost the same no matter the vehicle - at least when scaled down to the size of your texture. I recently did that with a door. Just grabbed a handle from a door, cut it out and scaled it for my door and it worked out much better than anything I could have done by hand. There's also the option of grabbing pictures yourself when you're out and around. If you have a phone with an alright camera, you can take pictures of cars you pass that has the details you're after, and again cut them out and apply them to your vehicle. Ofc how fast this will be compared to modelling the details depends on how comfortable you are messing around with images vs how fast you could model it.

Yea those details aren't too concerning for me; I'm used to that kind of thing. Where I really stumble is in trying to paint the highlights and shades of the main surfaces. Since what I'm going to be working on is fictional in nature and I'll be somewhat designing as I go I'll probably wind up having to model higher poly to really nail down the designs anyways. Those higher poly models will really only contain the main surfaces, too, so I think that workflow will wind up being almost perfect for this application, since I can bake the high-poly partial detail model down to the low poly model for the highlights and shades, and then paint/paste/etc the details from there.

[Mr_Maison 2,426]

Not sure if this helps in any way but I usually make a black and white image of the texture or parts of the texture I want AO, play around with levels then place on top of the original texture layer and multiply (tweaking that layer's transparency) to get the effect. I used it on my elevated train stations.

[boformer 3,169]

Are you actually talking about AO or normal maps? Because you could use a normal map to add extra details.

[Ryno917 102]

3 hours ago, boformer said:

Are you actually talking about AO or normal maps? Because you could use a normal map to add extra details.

Both, I suppose, but specifically an AO map. In the case of C:S it'd be the highlights and shading on the main diffuse texture. I don't have the skill to manually paint this stuff, and I can't simply use photographs since what I want to do is fictional. Was hoping there was another method, beyond just modeling a high poly vehicle and baking a texture from that, but it seems that's probably my best option.