# Tagged Questions

The simulation of light and illumination in games, including its interaction with the environment. A core element of games that can bring out vivacity into otherwise static worlds.

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### Simulating sun 3d direction

At the moment I got the following to simulate the suns direction: void Sun::Update() { if (!mIsMoving) return; const auto now = Clock::now(); const auto timeDiff = now - ...
333 views

### In a large space simulation, why is my sun light not reaching the planets?

I want to create a space simulation, but I'm facing some difficulties when I try to create a realistic sun. Currently, I've a simple Point Light inside a sphere. But for some reasons, no matter the ...
60 views

### Why is everything lit by default?

I am following the unity tutorial here and when i drag my environment into the Hierarchy everything i already lit up on my Game view, i noticed this was also the case in the Space Shooter tutorial ...
210 views

### What is a lobe, in reference to lighting and graphics

I sometimes see references to lobes when talking about lighting, especially with specular lighting, but also with spherical harmonics which doesn't do specular. Can anyone explain what exactly a lobe ...
212 views

### How to calculate spherical harmonic coefficients for indirect diffuse?

After reading the article "An Efficient Representation for Irradiance Environment Maps", I'm a bit confused as how to calculate the spherical harmonic coefficients. I'd like to generate these ...
60 views

### Inverting the Z coordinate of the light vector

I noticed that in some vertex shaders they invert the Z coordinate of the light vector, i.e. // Compute denormalized light vector in world space float3 vLightWS = g_LightPosition.xyz - vPositionWS....
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### How to calculate per vertex normals? (OpenGL) [duplicate]

I am really confused and quite much thinking about how to do that? Cross product and then, normalizing is not working for me. Or perhaps, I take them all wrong. Well, please explain me that while ...
269 views

### Deferred rendering: camera inside point light's sphere of effect

I'm trying out deferred rendering and I'm using the tutorials at http://ogldev.atspace.co.uk. I've got the basics working and I'm currently trying to implement the final step from tutorial 37 (http://...
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### LWJGL Lighting advice / fix

Problem: The spotlight I've set up with OpenGL won't light up anything behind it, no matter what values I set for GL_SPOT_DIRECTION float[] LightDir = new float[]{0,0,-1,0}; float[] ...
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### WebGL Multiple Lights, Blending, and Render Order

I am trying to do simple forward rendering for multiple lights using additive blending in WebGL. Following advice from this SO and this one, I simply turn on blending using glBlendFunc(GL_ONE, GL_ONE) ...
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### Why do my point lights have red X's on them in the Unreal editor?

I've noticed through the first two tutorials I've done that Point Lights begin entering the viewport with red x's on them. When I build those don't turn on. It seems to be implying some limit to the ...
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I have a script that changes the levels using Application.LoadLevel (sceneNameToChangeTo); Once a level is loaded using that code when testing with the editor, the lighting changes dramatically. I'...
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### Phong shading blows out things close to white [OpenGL]; is there a way around this?

I'm doing per-pixel lighting using the Phong shading model. In pseudo code this looks like: vec4 ambientColor = light.ambientIntensity * material.diffuse; vec4 diffuseColor = light.diffuseIntensity *...
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### Creating Lighting effect in openGL [duplicate]

I am trying to make my wall have the same color and shade as the walls shown in the picture (Please ignore the frame and the bulbs). I can create a a cube and view it from inside but how can we give ...
3k views

### Making a night scene without being dark on the monitor

What would be a good way to make a 3D scene look "like" a dark night, without being so dark on the monitor that it's hard to see stuff (especially when playing in a brightly lit room). I've been ...
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I know that the formula for irradiance at surface point p with normal n given a point light source at position l is: H = I(cos x) / ||l - p||^2 Where: x = angle between n and l-p I() = Intensity ...
260 views

### Proper normal vector transformations in normal mapping

Hello! This question is about transforming normal vectors from normal maps properly. I have tried methods from over five sources, still can't get it to work, and I'm really desperate. Included are ...
2k views

### What causes this graphics quality difference between WebGL Build and Unity 5 Editor?

The Editor version and WebGL version of my Minesweeper clone have some graphics quality differences. I chose 'Fast' option when building this deployment. Is this the difference between 'Fast' and '...
136 views

### Incorrect Normal Matrix

In my game engine I'm passing a normal matrix to my shaders like so: Matrix3f normalMatrix = modelMatrix.invert().transpose(); However this is causing lighting to rotate with my object, producing a ...
607 views

### How to cast colored shadows

I have a glassy object and when light passes through it I want it to cast colored light behind it, instead of the shadow. I could just use another light object to cast that colored light, but is it ...
830 views

### Unity 2D: Sprites/Diffuse is making my character weird, like an antialias

i'm trying to put light and shadows on my 2D character but when i set the material on it to Sprites/Diffuse, it's kinda putting a strange smooth on my pixels. Without diffuse: With diffuse: And ...
161 views

### Sprite outline based on light position in UE4

I have simple sprite (for example black box) and I like to add to it outline (red line on example image) but based on light direction. I know UE4 use deffered renderer, so I cant access to lights, but ...
163 views

### Rectangular area light illuminance - colour banding

I'm currently working on an implementation of rectangular area lights but I am having some issues with the illuminance calculation, which gives me serious colour banding across the entire lit area. I'...
856 views

### Custom shadowmapping in Unity not working properly

To experiment with a certain technique, I'm implementing my own shadow mapping in Unity. I'm using a camera for the light "view", which is rendered to a RenderTexture after being post-processed with ...
231 views

### Imported Blender modular mesh lighting/shadows issue - Unity

Hi I've very recently started using Unity and am creating a game level. I've created my environment in blender and am currently using a modular design as I'd like to include destructible environments. ...
891 views

### Are shaders the only way to implement 2d lighting?

I'm working on a 2d top down game with libgdx and I think i got the basics. No want I want to implement lighting, I don't know anything about lighting. I want just to have some light sources and ...
331 views

So I have a scene, completely based on 2D sprites. I want to render "light sources" into a seperate frame buffer (so mostly dots around, for example, the centre of a flame) and then render that frame ...
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In several topics here it was suggested by people that doing lighting in tangent space is better than doing it in world space. Right now I am doing it in camera space, but it's really similar to world ...
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### What are 'ambient' lighting/illumination/occlusion? [duplicate]

What's the difference between ambient lighting,ambient illumination and ambient occlusion ? What are they? What's the difference between them?
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### Box2D Lights - Simulate water

I have a libGDX project, in which I have a Box2D world, which is currently filled with some boxes as a terrain. I also added a DirectionalLight to the scene for simulating the Sun. I almost have the ...
1k views

### What are 'physically-based' lighting/rendering/materials?

What's the difference between physically based lighting, physically based rendering and physically based materials? How they are different from deferred and forward rendering? And physically based ...
192 views

### Rendering lighting only on specific objects

I have done something similar to this in monogame: My question is, what would I have to do to draw that lighting effect only on the pillar and not the background ? Is there something like ...
74 views

### Where is Light in Game view

Very Basic Question.when i run the the game the game Mode is Too dark as shown below in the picture. please suggest me some Setting how to globally switch on built in light while Running the game in ...
111 views

### OpenGL light calculation

I want to add somebasic point lights to my OpenGL application. I read here that I have to caluclate the light in a pre-projection space: Lighting can be done in any pre-projection space (e.g., ...
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### 2D GLSL Lighting and Sprites

I'm trying to make a 2D game engine, and I really want to support ambient light as well as multiple point lights that you can define the color, intensity, radius, etc from uniforms in glsl shaders. ...
415 views

### Hide some objects from the camera (fog)

I'm trying to implement a visibility representation in a 2D game ( no plains, no quads - plain 2D ) In the examples below I have calculated what the player can see using raytracing and added all the ...
1k views

### Three.js: Lighting not calculating correctly on THREE.Geometry objects

I have a three.js (REVISION: '68') issue with the lighting of THREE.Geometry objects: I'm using the THREE.Geometry class to build up objects using vertices and faces, then I computeFaceNormals() ...
241 views

### Reflection/environment mapping

I'm implementing reflection/environment mapping using a cubemap. I have it working for the most part but when I move my camera around, I see the same area reflected on the object. I am calculating the ...
386 views

### GL_SPOT_CUTOFF not working properly

I'm new to OpenGL. I'm studying OpenGL 2.1 and I'm trying to make a little program to test the GL_SPOT_CUTOFF property, but when I set a value between 0.0-90.0, the light doesn't work and everything ...
189 views

### Normal Mapping issue

The first image shows a spotlight shining correctly on the floor. The second image shows the same spotlight but rotated 180 degrees. The first is correct, the second is not. The third image shows ...
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### SFML - Rendering a torch with a fire animation [duplicate]

I have coded a 3D maze simulator in SFML using raycasting. However, I want to add a torch to the screen, so that the lighting seems more realistic. From my understanding, I would have to use ...
452 views

### How does an energy-conservative Blinn-Phong-Fresnel model work?

What is a plausible, basic equation/pseudo-code for energy-conservative Blinn-Phong shading, including Fresnel with a coloured light-source? The net gives so many alternatives that it's hard to ...
629 views

### 2D Smooth Tile Lighting

I am currently working on a 2d platformer and have the general idea of how to apply 'lighting' to my level, but I am not sure at all how to make it smooth, similar to Terraria, as you can see here. ...
332 views

### How can I build Minecraft-style light propagation without recursive functions?

This question is more about expanding on an answer posted for an old but similar question. Part of the answer says this: You simply fill the sunlight from the top to the bottom, every layer is ...
1k views

### OpenGL light appears to move with camera and changes with object rotation

I have a working open gl es 2.0 3d engine (my own) that I've used in several iOS apps. I recently noticed that on a mutli-symmetrical object the lighting didn't look the same at each rotation. For ...
1k views

### model view projection multiplication order

I'm debugging a lighting problem where the camera position is effecting the diffused lighting component on my 3d model. In researching my problem I went back and am reading over all the how to ...
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### Why is 2D light ray collision result getting inverted at specyfic angle

recently i've been working on 2D lighting for my game. I've created new little project, and I've encoutered a problem. The collision between light ray and the object is fine at angles 316-360 and 0-...
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### Smooth seams and banding of overlapping lights in deferred rendering

I have finally managed to get on screen multiple lights with a deferred renderer, but the result is somehow disappointing. In particular I have severe banding problem Other than having clear ...