Yesterday or so I have created a little System for my Game which generates Rooms for a Labyrinth or Maze according to a Code that is read when going through an Exit. While the Basics work, I also would like to refine it with two Features...1) ... for which I should get String of that "CaveCode"-Code turned into a Number, meaning to extract only the Numbers and ditch the Letters and an Underscore. I am not very familiar with String-Manipulation, be it in Lua or anywhere else (just not used to using it), so after some little Research I thought the following Line with a "%d+" supposedly finding all the Digits should work, but it doesn't and I don't know what I am doing wrong -- so, I'd be thankful to get some Help on this.Values.CaveCode.Int = tonumber(string.find("02a_00a04a03a01b","%d+"))Another Thing I noticed was what looks like a Glitch, but I am not sure about it. One of the Refinements I mentioned is that I want the Graphics for the Maze to be distorted depending on a Seed that shall not be random but belong to each Room's different Perspectives (so I should just extract the Digits from the CaveCode).2) The Problem is that when I apply a Shader to a Scene-Object, its UV will -- even if the original Graphic was filling the entire Screen -- be cut down to the Measures of actual Content abve zero Alpha. I am sure that is a good Feature for getting rid of unneeded Bytes and Megabytes being shoved into the Cache, but this is one of the Scenarios where it can be a slight Hindrance to my artistic Vision: When I use a Distortion-Shader on an Object, the Parts that should be followed by some empty Space with 0 Alpha, the UV Border is instead right where the Wall-Graphic ends, and thusly the Distortion is restricted to that Area and cannot go beyond, meaning that one Side of the Wall remains straight and undistorted, while the Rest is distorted.So I considered to just add some unnoticable Pixels with an Alpha-Value of maybe 2 or 3% in the opposite Corners of my Maze-Graphics, which automatically makes the Shader equally stretch across the whole Screen for each of the Graphics (because they all fill that exact Space). That Technique works for basically all Elements except the left Wall- and Exit-Graphics, which suddenly seem to have an Area which is not affected by the Shader (which becomes obvious because the Shader also colors the Graphics (because the Cave-Walls shall subtly change Color as you progress through the Maze), but not in this Area. It seems to be that Area which, at the Top and the Bottom, touches the UV-Border with Alpha above zero.This might not necessarily be as big a Problem once I replace my provisoric Placeholder-Graphics of just gray and white Cube-Walls with more organic and concavely shaped Cave-Walls, as their Shape would allow for the Shader to work even if the UV does not fill the entire Screen (which I guess sounds nonsensical, but it makes Sense), BUT then I would still have the Problem of the Shader's Distortion being scaled differently on different Elements, although I want the Distortion to be distributed evenly across the whole Screen.I suppose the more elegant Way to solve that Problem then would be to make it so the Shader's UV does not use the UV of the Object it is applied to, but that of the Screen, as if it was a Screen-Shader. But I haven't yet wrapped my Head around how to do that, even though I tried to look it up.So, either I have to make the Graphics all forced to be fullscreen and then get rid of that white Area, or otherwise learn how to use the Screen-UV for Effects to be applied to an Object. Any Ideas?

@ AFRLme: Well, that sounds a little Bit totalitarian, doesn't it? I am reminded of the Ultima Games, where the Story-Focus lies on several very altruistic Virtues, and then in one Game these same Virtues are forced onto the People by a totalitarian Regime and all of a sudden it really doesn't sound quite as nice anymore. (Very close to Reality.)@ SimonS: Though I do not know that right now, I do assume that the Game's Performance might benefit anyway if a Shader is only active while the Scene it is for is running (do added Shaders on another Scene still "run" and eat up Performance, like looping Functions?), so it might be better anyway if I add and remove these specific Shaders Scene by Scene -- that Way the Shader will work fine, and maybe it'll even help the Performance. So, since I have found some Sort of Solution, I guess that last Problem of mine is of very little Importance, but none the less a Bit of a Problem (since one Shader on multiple Objects works fine with the No-Toolkit Form), and I can at last be at Peace. (Even though I am not entirely sure whether this qualifies for the Topic to be marked as "SOLVED" or not.)Thank you very much for all the Help so far, Simon.

Thank you very much, now the Shaders work! And I was quite ecstatic about not having to use the (indeed quite ugly) Main Loop, so I immediately changed the other already working Shaders from the "Without the Shader-Toolkit"-Form into the "With the Shader-Toolkit"-Form because the former didn't take the bind()-Command and thusly seemed to need the Main Loop...... but this has led me to another Problem: It worked fine when I was using the "No-Toolkit"-Form with the Main Loop on two Cloud-Objects, each in a different Scene and each having its own Script adding the same Shader but with different Values. Now that I have rewritten the Code into the "With-Toolkit"-Form and using only bind() instead of the Main Loop, only the second Cloud-Object will get its Shader updated, the first will be stuck.Both Scripts are Definition Scripts, so maybe I would have to go the extra Mile and turn them into Execution Scripts and turn the Shaders on or off depending on what Scene the Player is in? I tried to add shaderRemoveEffect inside the Script, before shader AddEffect (which I know can work on my Day-Night-Cycle to ensure it is not running before another Scene adds it), but here with the Cloud-Shader on two separate Objects, it doesn't seem to work.So now I am torn between the seemingly only halfway working bind()-Form and the ugly but working Main Loop. Is there a Way to fix that Issue with the bind()-Form alone?(P.S.: I know it is a little bizarre that I keep up the English in a Dialogue between two German-Speakers, but in Case other People encounter the same Problems, I think the Problems and their Solutions should be available to every User on the Forum, so I prefer to keep it up.)

Thank you very much! I got the Clouds to work (and at Least it is quite a Blessing that seemingly Shaders no longer depend on rightly ordered IDs). Even though there is still a reeeally miniscule "not quite wrapping" Border visible (comparable to when I clamped the Coordinates), that is next to invisible, and thusly not a big Deal. Now I am happy with that Cloud-Effect.Though now I am trying to implement another Shader applied to the whole Screen (namely my good old Day-&-Night Cycle), and I am following the Example from the Reference you gave me -- thank you very much for it! --, but alas, for some obscure Reason the Script just won't activate my "daynight"-Shader. Can you tell me what I am doing wrong? (I am sure the Mistake is some truly minor Detail, making this whole Question look utterly ridiculous, but I am afraid I just can't find it.)Here is the Shader (for the Sake of Completion)...#ifdef GL_ES precision lowp float; precision lowp int; #endif uniform sampler2D texel; varying vec2 uvVarying; const float pi = 3.1415926535897932384626433832795; uniform float daytime; void main () {  float x = daytime;  float R = (0.75+sin((x-3.0)*0.5*pi + cos((x-3.0)*0.5*pi))*0.25);  float G = (0.75+0.125+cos(x*0.5*pi)*0.125);  float B = (0.75+0.125+cos(x*1.0*pi)*0.125);  vec3 col = vec3(R,G,B);  gl_FragColor = vec4(texture2D(texel, uvVarying.xy).rgb * col, 1.0); }... and here is the Script:local eff = "daynight" shaders[eff] = shader(eff, Shaders[eff].Compiled) shaderAddEffect(eff) bind(eff, "daytime", field("Values.Daytime.Int")) function updateDaynight()  shader_effects[eff].num.daytime = Values.Daytime.Int * 0.0125 end registerEventHandler("mainLoop", "updateDaynight") 

You can use a shader for the character.I don't know why everyone's so afraid of GLSL.Create a shader Grayscale, change the Fragment to this:#ifdef GL_ESprecision lowp float;precision lowp int;#endifuniform vec4 color;uniform sampler2D texel;varying vec2 uvVarying;void main (){  vec4 col = (texture2D (texel, uvVarying) * color);  float grey = (col.r+col.g+col.b)/3.0;  gl_FragColor = vec4(grey,grey,grey,col.a);} Then using it (a definition script):local grayscaleShader = shaderCompile(Shaders.Grayscale.Compiled) function setGrayscale(char, active)   char.ShaderSet = grayscaleShader end setGrayscale(game.CurrentCharacter, true)Simple ay.