Skip to main content

Navigation Arrays and Navmeshes.

Today I worked on the prototype navmesh for the game.
Most 3d games use a navigation mesh, it's easier to store data about where you can walk in a mesh than in text arrays, the mesh can also be edited easier than rewriting an array.

Unfortunately with a random dungeon the different sections have separate navigation meshes, and in Blender you can't merge the meshes. So in this project I'm using the meshes to generate the list of walkable tiles and then they will be deleted and the data will be kept as an array. I'll be using simple neighbor checking to create a graph that can then be used with A* pathfinding.

It's all very old fashioned, but for me it's interesting to use these methods because it allows me to understand what's going on at a very basic level. I don't really expect to improve on modern AI but I can find what's good for my project and leave what I don't need.

Here's the walkmesh:

You can see the red areas are walkable, the green areas are a negative mask, I'll be using green walkmeshes to show where you can't walk. They'll be added to props to override the existing walkmesh when the prop is added.

Actually thinking about it, green for don't walk and red for walk is kind of counter intuitive. :)
Have to change that in the next update.

Here's a closer look:

The result is a a set of dictionaries, one for each tile. I'll be accessing the dictionaries separately when building the graph for A* so I don't have to access the whole set of data, hopefully speeding up performance a bit. Tiles which are out of range of the character's movement range will not be added to the graph. Characters will pathfind to a selected square inside their move radius, but it's up to the player to do long distance pathfinding each turn.

The AI will at first try to generate a path to the player using a cropped rectangle around the position of the player and the monster. If it can't reach it will expand the search area. This means that in some cases the A* routine may need to be run twice, however, in most cases it will work the first time, using much less resources than a full level graph.

I'm also thinking of doing a simple flood fill at the beginning of the AI's movement phase to find which players are accessible, or which are on islands (in a locked room for example).

Here's a quick video that shows the unfinished result:

Comments

Popular posts from this blog

Automating Level imports from Blender to Godot

  Recently I've been making some levels in Blender an importing them into Godot. There are only about 7 or 8 shaders for each level, not counting dynamic objects which will be added later. But to improve rendering performance, it can be a good idea to split the meshes up into sections. At that point you might be faced with a list like this: Or it might be even more chaotic, if you didn't use simple names for the objects in your level. So it can take a long time to sort out all the meshes, make them unique and add textures and so on. Blender imports with simple Blender textures, or with placeholder materials. This is sometimes OK, but if your Godot shaders are very different to those used by Blender, it means applying new materials to every mesh object in the level when you import the scene. I found that during the design process, I was importing and readying a level several times before I was happy with the final layout. So at first I was wasting a lot of time. In Blender, I us

Upstairs / Downstairs.

I've decided to make my prefabs multilevel. Later this should allow me to add pit traps and other great stuff. It also makes it easier to line up stairs so that you can exit them on the same co-ordinates where you entered them. The prefab editor is pretty much finished, it just needs some code for loading up prefabs from a saved dictionary, so that they can be checked or edited. The entries will need to be forwards compatible, so I'll be loading each tile and then translating the indexes to a new array, that way if I add extra indexes or extra info (like traps or puzzles) I'll be able to update existing prefabs to work with the new standard. Click for a video.

Make your game models POP with fake rim lighting.

I was watching one of my son's cartoons today and I noticed they models were using serious amounts of simulated rim lighting . Even though it wasn't a dark scene where you'd usually see such an effect, the result was actually quite effective. The white edge highlighting and ambient occluded creases give a kind of high contrast that is similar to, but different from traditional comic book ink work. I'll be honest, I don't know if there's a specific term for this effect in 3d design, since my major at university was in traditional art. I learned it as part of photography. You can find plenty of tutorials on "what is rim lighting" for photography. It basically means putting your main sources of light behind your subject so that they are lit around the edges. It can produce very arresting photographs, either with an obvious effect when used on a dark subject ... ..,or as part of a fully lit scene to add some subtle highlights. See ho