I have a problem in which in my game I have to use SpriteSortMode.Texture because I have a lot of objects with few textures, so I cannot afford to use SpriteSortMode.BackToFront.
The thing is this means I cannot draw by layers, unless I do SpriteBatch.Begin with the exact same settings, which is what I'm currently doing.
I only have 3 draw layers I need - a Tileset surface, Objects like rocks or characters on the surface, and UI.
Other solutions I've found is using texture quads (which supposedly also improves tileset drawing performance), going 3D with orthogonal view which I haven't researched yet.
I'm hoping there's a better to make this work.
Why would having a lot of objects with few textures mean you have to use SpriteSortMode.Texture?
"This can improve performance when drawing non-overlapping sprites of uniform depth." says the MSDN page, and this is clearly not what you are doing.
Just use the default SpriteSortMode.Deferred and draw things back to front in order.
Related
I have a 2D game in 4 directions, and I'm having problems with FPS (or GPU) because I have to draw a lot of textures.
I've read a lot about techniques to optimize performance, but I don't know what I can do anymore.
The main problem is that in some occasions I have about 200 creatures, where I have to draw his body (it is a single sprite) but also draw spells and other animations on his body. So, I think that is when it starts to give conflicts because the loop where I draw each creature, must change the textures for each creature, that is body>animation1>animation2>animation3 and this about 200 (creatures) times at 60 fps. Which lowers the fps to about 40-50.
Any suggestions?
This is how it looks:
The issue is probably - as you have already suggested - the constant switching between different textures. This is much slower than drawing the same number of sprites with the same texture.
To change this, consider putting all your textures into a single big texture. You then always draw that texture. This obviously would look quite wrong, so you also have to tell XNA which part of the texture you want to draw. For that, you can use the SourceRectangle parameter that can be passed to SpriteBatch.Draw(...). That way, you can always render the same texture but can still have different images on screen.
See also this answer about texture atlasses for more details.
My question maybe a bit too broad but i am going for the concept. How can i create surface as they did in "Cham Cham" app
https://itunes.apple.com/il/app/cham-cham/id760567889?mt=8.
I got most of the stuff done in the app but the surface change with user touch is quite different. You can change its altitude and it grows and shrinks. How this can be done using sprite kit what is the concept behind that can anyone there explain it a bit.
Thanks
Here comes the answer from Cham Cham developers :)
Let me split the explanation into different parts:
Note: As the project started quite a while ago, it is implemented using pure OpenGL. The SpiteKit implementation might differ, but you just need to map the idea over to it.
Defining the ground
The ground is represented by a set of points, which are interpolated over using Hermite Spline. Basically, the game uses a bunch of points defining the surface, and a set of points between each control one, like the below:
The red dots are control points, and eveyrthing in between is computed used the metioned Hermite interpolation. The green points in the middle have nothing to do with it, but make the whole thing look like boobs :)
You can choose an arbitrary amount of steps to make your boobs look as smooth as possible, but this is more to do with performance.
Controlling the shape
All you need to do is to allow the user to move the control points (or some of them, like in Cham Cham; you can define which range every point could move in etc). Recomputing the interpolated values will yield you an changed shape, which remains smooth at all times (given you have picked enough intermediate points).
Texturing the thing
Again, it is up to you how would you apply the texture. In Cham Cham, we use one big texture to hold the background image and recompute the texture coordinates at every shape change. You could try a more sophisticated algorithm, like squeezing the texture or whatever you found appropriate.
As for the surface texture (the one that covers the ground – grass, ice, sand etc) – you can just use the thing called Triangle Strips, with "bottom" vertices sitting at every interpolated point of the surface and "top" vertices raised over (by offsetting them against "bottom" ones in the direction of the normal to that point).
Rendering it
The easiest way is to utilize some tesselation library, like libtess. What it will do it covert you boundary line (composed of interpolated points) into a set of triangles. It will preserve texture coordinates, so that you can just feed these triangles to the renderer.
SpriteKit note
Unfortunately, I am not really familiar with SpriteKit engine, so cannot guarantee you will be able to copy the idea over one-to-one, but please feel free to comment on the challenging aspects of the implementation and I will try to help.
Hi I'm using Firemonkey because of it's cross platform capabilities. I want to render a particle system. Now I'm using a TMesh which works well enough to display the particles fast. Each particle is represented in the mesh via a two textured triangles. Using different texture coordinates I can show many different particle types with the same mesh. The problem is, that every particle can have its own transparency/opacity. With my current approach I cannot set the tranparency individually for each triangle (or even vertex). What can I do?
I realized that there are some other properties in TMesh.Data.VertexBuffer, like Diffuse or other sets of textures (TexCoord1-3), but these properties are not used (not even initalized) in TMesh. It also seems not easy to simply change this behavior by inheriting from TMesh. It seems one have to inherit from a lower level control to initialize the VertextBuffer with more properties. Before I try that, I'd like to ask if it would be possible to control the transparency of a triangle with that. E.g. can I set a transparent color (Diffuse) or use a transparent texture (TextCoor1)? Or is there a better way to draw the particles in Firemonkey.
I admit that I don't know much about that particular framework, but you shouldn't be able to change transparency via vertex points in a 3D model. The points are usually x,y,z coordinates. Now, the vertex points would have an effect on how the sprites are lighted if you are using a lighting system. You can also use the vertex information to apply different transparency effects
Now, there's probably a dozen different ways to do this. Usually you have a texture with different degrees of alpha values that can be set at runtime. Graphics APIs usually have some filtering function that can quickly apply values to sprites/textures, and a good one will use your graphics chip if available.
If you can use an effect, it's usually better since the nuclear way is to make a bunch of different copies of a sprite and then apply effects to them individually. If you are using Gouraud Shading, then it gets easier since Gouraud uses code to fill in texture information.
Now, are you using light particles? Some graphics APIs actually have code that makes light particles.
Edit: I just remembered Vertex Shaders, which could.
In 3d terrain that consists of thousands of cubes (i.e. Minecraft ), what is a way to handle each block in terms of location and rendering? More specifically, I know that drawing a primitive of a cube and world transforming it everywhere in directX 9 is probably a ridiculous way to accomplish this since there are so many performance issues, so I was wondering what a more reasonable method would be.
Should each cube be a mesh that's copied many times, or is their a way to create the appropriate meshes from the data in your vertex buffer?
I found this article that walks through some of the theory behind implementing what I want to implement, but I've never used octrees before so I wasn't able to take too much from the source code. If octrees are indeed the way to go, where is a good starting point to learn about them? Most of my google searches only turned up blog posts about theory with little or no implementation examples.
It seems like using voxels would be useful in doing this, but like with octrees, I'm coming from no experience here, so I don't really know what to study first.
Anyway, thanks for any advice\resources\book names you can spare. I'm sure it's obvious, but I'm still very new to 3d programming, so I appreciate your help.
First off if you're using Minecraft as your reference, think of their use of chunks and relate it to Oct-trees. Minecraft divides up their world into smaller chunks to handle the massive amount information that is needed to be stored so use Oct-trees to organize this data that will be stored. Goz has a very accurate description of how Oct-trees and Quad-trees work, so use his information as a reference.
Another thing to consider is that you don't actually want to draw every cube to the screen as this will eat up your framerate. Use Object Culling to only draw visible cubes to the screen. Again if you think Minecraft; have you ever encountered a glitch where you can see through the blocks and under the world? This is because Minecraft only draws the top layer of blocks. With this many objects on screen, it would be a worthwhile investment to look into Object Culling using both the camera frustum and occlusion query.
For information on using DirectX I would recommend any book by Frank Luna. I own this book myself and it never leaves my side when programming in DirectX. http://www.amazon.com/Introduction-Game-Programming-Direct-9-0c/dp/1598220160/ref=sr_1_3?ie=UTF8&qid=1332478780&sr=8-3
I highly recommend this book as I've learned almost everything I know about DirectX from it.
Upon a Google search I found this link that discusses Occlusion Culling, because Luna doesn't cover occlusion culling, only frustum culling. I hear the Programming Gems series mentioned a lot, but I can't attest to its name personally. http://http.developer.nvidia.com/GPUGems/gpugems_ch29.html
Hope this helps.
Oct-trees are fairly simple, especially axis aligned ones like those in mine craft.
It is basically just a 3D extension of the quad-tree. You may find it easier to learn about Quad-trees first.
To give you a quick overview of a quad-tree; basically you start off with a square. Now imagine placing a much smaller square in that square. If you wish to build a quad tree representing it you first divide the original square into 4 equal sized squares.
Next you check each quadrant and if the smaller square is in that quadrant you split that quadrant into 4 smaller sized squares. Then you check those 4 quadrants choose the quadrant and subdivide. Eventually your smaller square will be wholly contained in one or more quadrants inside quadrants inside quadrants (etc). You have now built your quad tree.
Now if you imagine you are searching for a specific square inside the larger square you can quickly see the bonus of a quad-tree. Instead of searching every possible square in the quad tree (equivalent to searching every pixel in a texture) you can now check the first 4 quadrants to see if they contain it. If one does you can check its 4 sub quadrants and so on until you find the smallest quadrant wholly containing your square (or pixel). This way you end up doing many fewer tests to find your object.
Now an oct-tree is basically the same thing but instead of encoding squares in squares you now encode cubes in cubes. Every cube can be split into 8 smaller octants (and hence the name oct-tree).
Oct-trees have the advantage that by knowing which octant you are starting in you can easily cast rays through the oct-tree to find collisions (as an octant is either full, partially full or it is empty). If an octant is empty then you pass right through it and then check the octant on the other side. If it is partially full you check its sub-octants and so on until you either find a full octant (ie you've hit a solid cube and you render it) or you pass through the octant entirely and hence there is no cube to render. This is how minecraft works (I'm guessing anyway ;)). This is also a good way of quickly rendering voxel data which more people are looking into these days as a possible future rendering mechanism.
Hope thats some help! :)
Oct-trees and quad-trees are useful for culling sections of your geometry to render. Minecraft uses 16x16x16 render blocks to break up the terrain into manageable pieces.
Another technique to consider is instancing. Instancing is where you tell the GPU to render an object multiple times in different locations. It's used for crowd rendering, trees, anything where the geometry is the same, but you have lots of them.
http://msdn.microsoft.com/en-us/library/windows/desktop/bb173349(v=vs.85).aspx
http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter03.html
Here is an article where the writer duplicates the minecraft renderer in OpenGL 4. While the code won't apply to your case the techniques (culling cubes that are surrounded, etc) can be applied to a directx renderer.
http://codeflow.org/entries/2010/dec/09/minecraft-like-rendering-experiments-in-opengl-4/
Don't be fooled by the blocky graphics and the low quality textures. Minecraft is an extremely complex renderer and you'll need to come up with ways to handle the sheer number of items involved. For example even a "small" part of the world, say 100x100x100 blocks is 1 million blocks. To push each block to the GPU as a separate mesh would kill your GPU. The Minecraft renderer is far more complex than most first person shooters when you get down to the technology.
I am trying to write a strategy game using XNA 4.0, with a dynamically generating map, and it's really difficult to create all the ground textures, having to distort them individually in photoshop.
So what I want to do is create a flat image, and then apply the distortion programatically to simulate perspective, by moving the corners of the image.
Here is an example done in photoshop:
How can I do that in XNA?
My answer isn't XNA-specific as I've never actually used the library; however the concept should still apply.
In general, the best way to get a good perspective effect is to actually give 3d coordinates and transformations and let DirectX/OpenGL handle the rest. This has great benefits over attempting to do it yourself - specifically, ease of use, performance (much of the work is passed on to your graphics card), and perspective-correct texturing. And nothing's stopping you from doing 3d and 2d in the same scene, if that's a concern. There are numerous tutorials online for getting set up in the third dimension with XNA. I'd suggest heading over to MSDN.