This includes winding order, normals and how to expose your mesh factory to Unity using editor script. One of the best features of Unity is how smooth the asset pipeline works where 3D models flows seamless from any 3D program into to the Unity scene editor. So why would you create meshes inside Unity? Actually there is a number of reasons:. A polygon mesh in Unity is created of triangles.
It is possible now!
The mesh consist of an array of vertices and indices:. The vertices are Vector3 positions and the triangle faces indices are integers The illustration above uses one based index, but Unity uses zero based indices. The Tetradron is created by 4 triangles. The first triangle has the vertex indices the vertices P1, P2, P4. By using shared vertices, with each vertex referenced multiple times, a mesh can be created very compact.
The code above creates the correct shape, but it has one serious problem. The problem is that the shading uses the vertex normals — and there is one vertex normal for each vertex The normals are the red line segments — this is rendered using the MeshDisplay component.
The normals are calculated using the face normals using the method RecalculateNormals. In this case we want sharp edges and do not want to share vertex normals.
Runtime mesh generation
This can be done by not sharing the vertices. If you are creating a mesh without sharp edges, you should use shared normals.
The following shows the source code without shared vertices. This means that each corner of the shape has three vertices one for each normal. This creates the hard edges we want for this shape. On the screen shoot to the right you can see the three normals at each corner.
In this script, create a static function with the annotation MenuItem. This will add the method as a menu item in Unity. Posted in Unity. By: Ranza on January 10, at Excellent article, thank you for sharing all this info. I changed my plane generating methods to incorporate this method, very useful indeed. I like your articles because they are descriptive and concise. By: Ippokratis on March 4, at Thanks for the tutorial!
For the triangles, since they have to be in counterclockwise, would it be instead of and instead of Hmm actually Unity is a left-handed coord system, so I guess your tris are actually left-hand rule order?The Mesh The main graphics primitive of Unity.
Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. It uses arrays to represent the triangles, vertex positions, normals and texture coordinates and also supplies a number of other useful properties and functions to assist mesh generation.
The mesh data is attached to an object using the Mesh Filter A mesh component that takes a mesh from your assets and passes it to the Mesh Renderer for rendering on the screen. More info See in Glossary component and the object will also need a MeshRenderer to make the geometry visible.
This component is accessed using the familiar GetComponent function:. The Mesh object has properties for the vertices and their associated data normals and UV coordinates and also for the triangle data. The vertices may be supplied in any order but the arrays of normals and UVs must be ordered so that the indices all correspond with the vertices ie, element 0 of the normals array supplies the normal for vertex 0, etc.
The normals are normalised Vector3s representing the directions, again in local coordinates. The triangles are specified as triples of integers that act as indices into the vertex array.
Rather than use a special class to represent a triangle the array is just a simple list of integer indices. These are taken in groups of three for each triangle, so the first three elements define the first triangle, the next three define the second triangle, and so on. An important detail of the triangles is the ordering of the corner vertices.
The Mesh class also has a lower-level advanced API that enables you to work with raw mesh vertex and index buffer data. This is useful in situations that require maximum performance or the lowest amount of memory allocations. Version: Language : English.
Unity Manual. Unity User Manual Anatomy of a Mesh. Example - Creating a quad.I usually don't read all of a post that is this long, but I've made an exception! Loved it! Very well written. Post a Comment.
Procedurally generated meshes in Unity without garbage. August 08, Procedural mesh generation is very demanding both on performance and memory. Hence, it is very useful to know how it works under the hood and every trick on how to improve it to eventually, make better, stutterless experiences.
I will try to add as much as possible of what I have found over the years and present profiler-proof which is, of course, "absolutely correct". By casting this little bit of doubt, we can begin. About this post I expected to focus solely on '-without garbage', but I realized that I can't go straight to the topic without introducing the reader to important concepts like the garbage collector and what Mesh class really is, and hence, why is this post at all this relevant!
In the process, hopefully, keeping the reader from making other mistakes in between the lines of code. In case you are an experienced procgen Unity developer and know what all this is about I should note that this post is filled with [bad] examples you might already know. If you only want to get to the point, then I advise you to just jump to the bottom of the post to the Conclusion chapter, it should be clear enough.
On the other hand, it certainly is a good thing if you already know how to make procedural meshes, because I will not focus on the "how to make" or "what does Mesh Renderer do? But it's not a requirement, since I am providing simple examples. Additionally, note that this article focuses on memory, and not on performance, which requires definitely a separate post -s, or actually a book! Wording: When I say 'mesh data' I mean the collection of vertices, triangles, uvs, normals, tangents, etc.
In this post, I will only use vertices and triangles because that's the least amount needed to make a mesh. In case you want to add more "datas", you can just extend the same templates shown in the post to include those too. This is true for every game, but especially games with fast paced gameplay where player reflexes play a large role; and VR games, which absolutely must run smooth on high frame rates to prevent motion sickness.
And seriously Because the fans would kill me for a single stutter! Another case is Thought of Trainwhich is a infinite train landscape watching experience. And since it's both constant-speed and VR, any dropped frame would be extremely jarring. This is the project where my quest for allocation elimination has started! But yeah, I know it's a huge post, so here, a naive advice in shortest short: Allocating and deallocating memory is slow! Garbage collection can freeze your game if a large amount of objects has recently been dereferenced Never allocate memory during active gameplay, and especially not every frame.
Instead create objects at the beginning and pool - reference it and modify instead of destroy-create.UV mapping refers to the way each 3D surface is mapped to a 2D texture.
Each vertex contain a set of UV coordinates, where 0. If the UV coordinates is outside the 0. The same way that each vertex is associated with a normal, each vertex is also associated with UV coordinates. This means that sometimes you need to duplicate the same vertex due to UV mapping. Basically what we are looking for is a way to go from 3D coordinates the local mesh-coordinates: x,y,z to 2D coordinates u,v.
The most simple approach would be to remove one of the 3D coordinates; One example of this is to set the uv-coordinate to the x,z coordinate. However this approach is rare useful. When a creating procedural generated mesh in Unity, you would most often want absolute control over where the UV coordinates are positioned.
Note that the vertex P3 is mapped to both P3a, P3b and P3c. Another thing to notice is that a lot of space in the texture is waisted. Here the town was created procedurally on a sphere and UV mapped to one texture.
The texture had 3 building facades and 4 rooftops. The UV mapping was done dependent of the height of the buildings, so that a building could have from 1 to 4 floors. Screen shot from 'Escape From Planet Zombie'.
Thanks for this so usefull tutorial.
PackTextures that returns a Rect. It start making sense now. By: Ippokratis on April 20, at Something that bothers me on the example is that there are redundant vertices you repeat 3 times each vertex on the vertices array. I found the same problem when trying to map a texture on a terrain this blog helped me out, thank you. By: Ezequiel Pozzo pozzoeRand on December 4, at GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together.
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Low poly mesh generation in Unity. C Branch: master. Find file. Sign in Sign up. Go back. Launching Xcode If nothing happens, download Xcode and try again. Latest commit.
Latest commit a Apr 27, You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Initial commit. Apr 16, Update AbstractMeshGenerator. Apr 17, Update FallOffType.
Apr 18, Create FractalIslandsGenerator. Apr 19, Add files via upload. Create MeshBuilder. Apr 21, Update NoiseGenerator. Apr 27, Update ProceduralLandscapeGenerator. Update TerrainGenerator2D.Use those scripts to procedurally create primitive meshes, with custom parameters. More to come later. If anyone has the code for a teapot, that'd be great.
I guess it's a tiny bit more complicated though. The entry point of those script must be a reference to a meshfilter's mesh. The return value is that mesh filled up. Regular sphere. This is a sphere without poles. And there is no UV yet, not sure how to go about it actually.
Dealing with all thoses vertices and indexes can give you a headache before you know it. To see things clearly, you can create a TextMesh, set it up properly small characters, anchor at middle-center and save it as a prefab. Jump to: navigationsearch. RecalculateBounds ; mesh. Optimize. Cos r10f, Mathf. Cross r1, Vector3. Rad2DegVector3. Count ; vertices.
Add middle. Add new Vector3 - 1f, t, 0f. Add new Vector3 1f, t, 0f. Add new Vector3 - 1f, - t, 0f. Add new Vector3 1f, - t, 0f. Add new Vector3 0f, - 1f, t. Add new Vector3 0f, 1f, t.Procedural Geometry - An Improvised Live Course
Add new Vector3 0f, - 1f, - t. Add new Vector3 0f, 1f, - t. Add new Vector3 t, 0f, - 1f. Add new Vector3 t, 0f, 1f. Add new Vector3 - t, 0f, - 1f. Add new Vector3 - t, 0f, 1f. Add new TriangleIndices 0115 ; faces.Note: This tutorial was written using Unity It assumes you are already comfortable programming games in Unity. Feel free to start with our basic Unity tutorials before doing this one.
But have you ever wanted to generate levels on-the-fly? Procedural generation of meshes for floors and walls, as opposed to simply laying out preconstructed models, offers a lot of flexibility and interesting replay value. However, most games play better with mazes that are both imperfect, with looping paths, and sparse, made from open spaces instead of tight twisty corridors. The reason for this choice is simply to get mazes into your game with the least amount of effort.
In this game, every level is a new maze that includes a treasure chest somewhere in the level. Each level has a time limit, and you can keep playing until you get caught.
Your score is based on how much treasure you snag. The starter package includes the following:. Start by adding an empty object to the scene. This object is simply an attachment point for the scripts that control the game. The first script will manage the overall game, while the second will specifically handle the maze generation. Add this script into the scene: drag the GameController script from the Project window and drop it on Controller GameObject in the Hierarchy window.
Notice that MazeConstructor was also added to Controller ; that happened automatically because of the RequireComponent attribute.
As for the data type, the maze boils down to a grid of cells. To display the maze data and verify how it looks, add the following method to MazeConstructor :. Remember to turn on Show Debug on the MazeConstructor component. Hit Playand the stored maze data which is just the default maze for now will be displayed:.