How are OpenTTD graphics (terrains, roads, buildings) made ?

[P24F]

Hello,

Could anyone please tell me how OpenTTD graphics (terrains, roads, buildings) are made ?
Which tools and softwares are used ?

I have been an avid player of 2D isometrics games such as RollerCoaster Tycoon, Sim City 3000 and Age Of Empires since my chilhood.
I am a web developper and would love to create a 2D isometric simulation game but I have no idea about how the graphics are created on these great games.

I know how to create a simple multiplayer game such as a Connect4 clone, but I'd love to create a game with 2D isometric graphics.
I should be able to code the AI, simulation, and games menus/options, but the graphic/image part is a completely new field to me.

Thanks in advance for any help and information you could provide me with !

Best regards,

[Taschi]

The graphics (i. e. the sprites) are created with basically any editing software - anything from MS Paint to Photoshop should be fine.

Finding a program that can create beautiful images isn't the hard part, I have like a dozen of those - the hard part is learning how to create appealing artwork, and that is a far more complex question which I'm afraid doesn't have any easy answers.

[P24F]

Some OpenTTD sprites are really done with MS paint ? So each pixel is defined from scratch by hand ? Wow, that sounds crazy

[perverted monkey]

Indeed! Each pixel is precious and should be treated with care. But consider that drawing in 3D, as in blender, and rendering is more time consuming. You 'd better cooperate with a graphics artist or even more.

[Quast65]

Some OpenTTD sprites are really done with MS paint ? So each pixel is defined from scratch by hand ? Wow, that sounds crazy

They don't call it pixel-art for nothing!

[Eddi]

the games you listed, maybe with the exception of age of empires, predate widespread 3D capabilites, so putting each pixel by hand was the much easier approach.

nowadays you have more tools available that can help you, but if you want to turn a 3D model into a sprite, you usually lose a lot of details.

[Taschi]

Some OpenTTD sprites are really done with MS paint ? So each pixel is defined from scratch by hand ? Wow, that sounds crazy

That doesn't really change if you use better tools, like Gimp or Photoshop. When working in an environment with a) very small graphics and b) restricted color palettes, manipulating individual pixels will generally have better results than creating a larger picture with regular digital painting techniques and then scaling them down.

The emphasis here is on "generally" - there are things like the Czech Replacement Set (which ditches the restrictions on size and color palettes in favor of larger, full-color sprites) or Timberwolf's UK Trains (which are rendered from voxel models, as far as I understand) which use other approaches.

Also, since you mention Sim City 3000 - I think that the buildings in that game were originally modeled as voxels and then rendered into 2d sprites. At least I remember messing with the building editor (which shipped with my version of the game but I'm not sure if it was in all versions), and that seemed very voxel-y to me.

In fact, building 3d models, rendering them into 2d sprites and shipping them with games that are not capable of dynamically rendering 3d is not that uncommon - the Donkey Kong Country games, Locomotion and Rollercoaster Tycoon, and strategy games like Anno 1503 / 1503 AD use this approach as far as I am aware. There's probably far more of them. But that's something from the late 90es / early 2000, and Transport Tycoon predates them a fair bit. So, if you want to approximate the visual style of Transport Tycoon (original or Deluxe), pixel art is the way to go.

[P24F]

First of all, thank you all for your answers.

nowadays you have more tools available that can help you, but if you want to turn a 3D model into a sprite, you usually lose a lot of details.

After further research, I indeed realized that a sprite could be made from a 3D model that is then "degraded" to a 2D isometric image.
That is very interesting know, especially for a beginner like me who has no experience in creating a sprite from a blank image / scratch.

UK Trains (which are rendered from voxel models, as far as I understand).

It is the first time I read the terms "Voxels" :
This concept might be an easy way out for somebody like me who wants to start making a 2D isometric game without spending much time on textures, I'm going to take a closer look at this.

the games you listed, maybe with the exception of age of empires, predate widespread 3D capabilites, so putting each pixel by hand was the much easier approach.

When working in an environment with a) very small graphics and b) restricted color palettes, manipulating individual pixels will generally have better result

I see, after analyzing some images published on the forum, I think I could eventually try to create sprites and textures from already existing ones.
With this approach (modifying sprites unstead of creating ones from scratch), editing pixels might be much more accessible for me.

Image (carrier) found on the forum :


My attempt to make sand texture based on the previous image :


This leads me to the following questions :
- In the "sand" and "carrier" image, I notice the repetition of a 64px*64px texture/image as well as a 64px*32px "isometric pattern/image" : Which one of both is actually used/created ?
- In order to play around with existing sprites and textures, I have downloaded openTTD's source code but I am unable to find sprites and textures : Could anyone tell me in which folders I should look to find them ?

Thanks,

[Taschi]

I'd advise against looking too closely at OpenTTD's code. The project started over a decade ago and back then, there were fewer tools available for gamemaking. And generally, the OpenTTD code is somewhat inconsistent, partially due to shifting design paradigms and partially due to the fact that two major new C++ versions have been released since the project started.

In your place, I'd look at more modern and high-level game engines like Unity, which take a lot of low-level graphics stuff off your hands, and are also fairly well documented.

And for the OpenTTD sprites, those are not in the OpenTTD repository but in the OpenGFX repo on Github iirc.

[Eddi]

- In the "sand" and "carrier" image, I notice the repetition of a 64px*64px texture/image as well as a 64px*32px "isometric pattern/image" : Which one of both is actually used/created ?
- In order to play around with existing sprites and textures, I have downloaded openTTD's source code but I am unable to find sprites and textures : Could anyone tell me in which folders I should look to find them ?

OpenTTD doesn't come with graphics, they're in a separate "base set"

you should take a look at the OpenGFX base set:
https://github.com/OpenTTD/OpenGFX

[P24F]

In your place, I'd look at more modern and high-level game engines like Unity, which take a lot of low-level graphics stuff off your hands, and are also fairly well documented.

Thank you for these information and feeback.

And for the OpenTTD sprites, those are not in the OpenTTD repository but in the OpenGFX repo on Github iirc.

you should take a look at the OpenGFX base set:
https://github.com/OpenTTD/OpenGFX

Awesome, thanks !