I have a very simple but large scene containing lots of objects and a lot of these objects are small but curved objects so they have large polygon counts. The FPS on the scene is really horrible. I learned that a Level of Detail optimization should help alot.
I am using three.js and it has an option to set LOD. But the model, doesn't have any LOD information (alternate meshes for each object corresponding to distance from the object). Is there something like a tool to generate this information by automatically by decimating the original mesh to create the alternate meshes?
But I can't imagine how textures will be skinned on the decimated meshes. Do I have to manually create the LOD information? 3D editors like Blender, 3dsMax, Unity editor let me set these meshes up individually. But I have about 200 meshes in my scene.
Level of Detail information can not be generally generated automatically. And yes it a painstaking process to create the LOD info. You can look at the LOD Book site for help.
The accepted answer to this question is actually not quite correct anymore.
While it's true that it's a painstaking process to create LOD data it gets easy when using InstaLOD. InstaLOD is a fully automatic 3d optimization solution that's able to optimize any static and skeletal mesh and maintain all vertex attributes like texture coordinates. Besides the polygon optimization, InstaLOD also features remeshing, occlusion culling, imposter creation and other unique methods related to the optimization of individual 3D models and complex scenes.
DISCLAIMER: I am one of the devs of InstaLOD.
Related
I am currently developing an asteroid mining/exploration game with fully deformable, smooth voxel terrain using marching cubes in Unity 3D. I want to implement an "element ID" system that is kind of similar to Minecraft's, as in each type of material has a unique integer ID. This is simple enough to generate, but right now I am trying to figure out a way to render it, so that each individual face represents the element its voxel is assigned to. I am currently using a triplanar shader with a texture array, and I have gotten it set up to work with pre-set texture IDs. However, I need to be able to pass in the element IDs into this shader for the entire asteroid, and this is where my limited shader knowledge runs out. So, I have two main questions:
How do I get data from a 3D array in an active script to my shader, or otherwise how can I sample points from this array?
Is there a better/more efficient way to do this? I thought about creating an array with only the surface vertices and their corresponding ID, but then I would have trouble sampling them correctly. I also thought about possibly bundling an extra variable in with the vertices themselves, but I don't know if this is even possible. I appreciate any ideas, thanks.
Perhaps the question is not that correct, the textures should be say a kind of channel? although I know they will be mixed in the shader finally.
I know the knowledge of the various textures is very important, but also a bit hard to understand completely.
From my understanding:
diffuse - the 'real' color of an object without light involved.
light - for static objects. render light effections into texture beforehand.
specular - the area where has direct reflection.
ao - to absorb indirect light for the different area of an object.
alpha - to 'shape' the object.
emissive - self illuminance.
normal - pixel normal vector to deal with the light ray.
bump - (dont' know the exact differences between normalmap).
height - stores Z range values, to generate terrain, modify vertex etc.
And the items below should be related to PBR material which I'm not familiar with:
translucency / cavity / metalness / roughness etc...
Please correct me if some misunderstandings there.
But whatever, my question is why we need to separate these textures apart for a material but not only render them together into the diffusemap directly for a static object?
It'll be appreciated if some examples (especially for PBR) , and thank you very much.
I can beforehand bake all things into the diffuse map and apply to my
mesh, why I need to apply so many different textures?
Re-usability:
Most games re-use textures to reduce the size of the game. You can't if you combine them together. For example, when you two similar objects but you want to randomize the looks of them(aging effect), you can make them share the-same color(albedo) map but use different ao map. This becomes important when there hundreds of objects, you can use different combination of texture maps on similar objects to create unique Objects. If you have combined this into one, it would be impossible to share it with other similar objects but you to slightly make to look different.
Customize-able:
If you separate them, you'll be able to change the amount of effect each texture will apply to the Object. For example, the slider on the metallic slot for the Standard shader. There are more of this sliders on other map slots but they only appear once you plug a texture into the slot. You can't do this when you combine the textures into one.
Shader:
The standard shader can't do this so you have to learn how to write shader since you can't use one image to get the effects you would with all those texture maps with the standard shader. A custom shader is required and you need a way to read the information about the maps in the combined shader.
This seems like a reasonable place to start:
https://en.wikipedia.org/wiki/Texture_mapping
A texture map is an image applied (mapped) to the surface of a shape or polygon. This may be a bitmap image or a procedural texture. They may be stored in common image file formats, referenced by 3d model formats or material definitions, and assembled into resource bundles.
I would add to this that the shape or a polygon don't have to belong to 3d objects as one may imagine it. If you render two triangles as a rectangle, you can run all sorts of computations and store it in a "live" texture.
Texture mapping is a method for defining high frequency detail, surface texture, or color information on a computer-generated graphic or 3D model. Its application to 3D graphics was pioneered by Edwin Catmull in 1974.
What this detail represents is either some agreed upon format to represent some property, (say "roughness" within some BRDF model) which you would encounter if you are using some kind of an engine.
Or whatever you decide that detail to be, if you are writing your own engine. You can decide to store whatever you want, however you want it.
You'll notice on the link that different "mapping" techniques are mentioned, each with their own page. This is the result of some person, or people who did some research and came up with a paper detailing the technique. Other people adopt it, and that's how they find their way into engines.
There is no rule saying these can't be combined.
I want to create procedurally generated landscape meshes with a flat shaded look in Unity3D.
I thought it would be the best to create three unique vertices per triangle and use one calculated normal for the vertices. Building this mesh would lead to redundant vertex position information. (Would it have an impact on render time?)
Anyway... the problem is that I would like to use shading techniques e.g. ambient occlusion on this mesh. I don't want to mess up the mesh topology that Unity3D expects for its shaders.
Is it better to create the meshwith shared vertices, add perhaps a custom vertex attribute e.g. 'flat_normal' and customize the shaders to use this?
The simple answer is
No,
Unity does not, in the slightest, "look for" shared verts. No 3D pipeline has anything to do with shared verts. Shared verts does not help or hinder the 3D pipeline in anyway at all.
(Very often, when for example we are making dynamic mesh, we just "never use shared verts at all" because, as you have probably found, it's often far simpler to not use shared verts.)
The one and only reason to use shared verts is if, for some reason, it happens to make it more convenient for you. In that case the 3D pipeline (Unity or elsewhere) "allows" shared verts, with no downside.
There might be 2 considerations for using shared vertices:
To reduce memory usage. (Only slightly, but if you need less UV1's, UV2's, normals, vertices it can add up)
to make it more convenient to share normals. (You only have to alter one normal of a vertex if you want to keep the surface smooth. )
These are no big reasons, but as most of the meshes from other 3D programs that you encounter, it's probably best to get used to shared vertices.
I have a big complex unity scene including terrain, trees, grass, flowers and many other objects.
I'm having performance problems and i was wondering if its possible to bake all static objects that never move or change like terrain trees, houses, and other props etc, into one big static object to increase performance?
Thanks
Check out the Unity documentation on Static Objects here.
Many optimisations need to know if an object can move during gameplay. Information about a Static (ie, non-moving) object can often be precomputed in the editor in the knowledge that it will not be invalidated by a change in the object’s position. For example, rendering can be optimised by combining several static objects into a single, large object known as a batch.
To mark a GameObject as static, you simply need to check the Static box in the inspector window with the desired GameObject selected.
That wouldn't be a good idea. Having separate meshes is much more beneficial and efficient than combining them all into one huge mesh. This will allow you to set different LOD systems for the objects, billboarding of trees and detail objects, and will allow for finer control over your scene without having to rebuild that huge object again and again.
For large scenes, it is important that you set up a Level Of Detail (LOD) system. What it essentially means is that based on the distance of the object from the camera, a higher or lower quality model of that object will be rendered. At close distances, the highest polygon model will be rendered. At huge distances where detail is not required, lower polygon count models can be used. Consult the Unity Manual for more details. You can also look for scripts and tutorials on the internet.
Also, make sure that your terrain settings are reasonable. Setting the Pixel Error of the terrain to 1 is overkill, something like 4-5 is more than enough. Detail Density, Billboard Start, Detail and Tree Distance all these can be toned down.
Or just check for an unoptimized script or shader gone awry, that's usually the problem. Unoptimized 3d models are hell too. You'll have to do more than just pick up a model from Sketchup's 3D warehouse (speaking from personal experience). You will have to pay an artist to get high quality, optimized models with their LOD meshes also unless you have the skills yourself.
This question is (mostly) game engine independent but I have been unable to find a good answer.
I'm creating a turn-based tile game in 3D space using Unity. The levels will have slopes, occasional non-planar geometry, depressions, tunnels, stairs etc. Each level is static/handcrafted so tiles should never move. I need a good way to keep track of tile-specific variables for static levels and i'd like to verify if my approaches make sense.
My ideas are:
Create 2 Meshes - 1 is the complex game world, the second is a reference mesh overlay that will have minimal geometry; it will not be rendered and will only be used for the tiles. I would then Overlay the two and use the 2nd mesh as a grid reference.
Hard-code the tiles for each level. While tedious it will work as a brute force approach. I would, however, like to avoid this since it's not very easy to deal with visually.
Workaround approach - Convert the 3d to 2D textures and only use 1 mesh.
"Project" a plane down onto the level and record height/slope to minimize complexity. Also not ideal.
Create individual tile objects for each tile manually (non-rendered). Easiest solution i could think of.
Now for the Unity3D specific question:
Does unity allow selecting and assigning individual Verts/Triangles/Squares of a mesh and adding componenets, scripts, or variables to those selections; for example, selecting 1 square in the 10x10 unity plane and telling unity the square of that plane now has a new boolean attached to it? This question mostly refers to idea #1 above, where i would use a reference mesh for positional and variable information that were directly assigned to the mesh. I have a feeling that if i do choose to have a reference mesh, i'd need to have the tiles be individual objects, snap them in place using the reference, then attach relevant scripts to those tiles.
I have found a ton of excellent resources (like http://www-cs-students.stanford.edu/~amitp/gameprog.html) on tile generation (mostly procedural), i'm a bit stuck on the basics due to being new to unity and im not looking for procedural design.