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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14
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3answers
3k views

What is the utility of squared radius and inverse squared radius for lighting computations?

On one of the slides from "DirectX 11 Rendering in Battlefield 3" PowerPoint I noticed the folowing code: struct Light { float3 pos; float sqrRadius; float3 color; float invSqrRadius; } I ...
1
vote
0answers
37 views

SpotLight in ForwardBase pass using forward rendering

Is there anyway I can force Unity to allow me using a custom shader to render spotlights in a ForwardBase pass (using Forward Rendering Path)? For what I could see since now: Unity use and ...
3
votes
1answer
101 views

Understanding and editing HDR light environments in Photoshop

I'm working with an in-development system that uses .hdr environments (equirectangular projection) to provide image-based lighting (IBL) to a 3D rendering. I'm trying to understand what range of ...
1
vote
1answer
32 views

Correcting Lighting in Stencil Reflections

I'm just playing around with OpenGL seeing how different methods of making shadows and reflections work. I've been following this tutorial which describes using GLUT_STENCIL's and MASK's to create a ...
1
vote
1answer
63 views

How to create a sun billboard with Ogre3d

I've been working with a few different engines alongside trying to code my own project. Rather than rewrite an entire renderer, etc I am using Ogre3d. To begin with I am trying to implement a very ...
3
votes
0answers
67 views

Creating a black light (ultraviolet) shader?

I am interested in the algorithm for color picking that would ideally allow to choose what color range will be highlighted and what color range will be faded. I can sort-of understand how to make it ...
0
votes
0answers
23 views

Cone Lighting formula for 2D projection space?

There is a good formula for a 3d cone lighting: float angleCos = dot(lightVector.rgb, lightDirection.rgb); attenuation = saturate((angleCos-coneCos)*coneCos); What if I want to compute whether my ...
1
vote
1answer
78 views

Why is the light following my camera around?

I have implemented a simple Phong shader without specular highlights for now (just ambient + diffuse components) The problem however, is that the calculations seem to be done in camera space; as I ...
0
votes
2answers
30 views

Compute cone angle (cos) given side and hypotenuse vectors at time 0 and world matrix at time 1

I need a formula for the cosine of a cone, given normalized side vector, normalized hypotenuse vector at time 0 and world matrix at time 1. This is needed to implement custom spotlights in a level ...
0
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0answers
29 views

Checking if a object is blocking my view of a light (it's between light and camera)

I'm trying to determine, from a list of objects, which ones are blocking my view of a light. In other words: which ones are between the light and the camera. Coding in C++, using HPL1Engine. This is ...
0
votes
1answer
49 views

Surface shader ignores lighting in vertexLit path

I want to use a surface shader in VertexLit(not Forward) rendering path. I caused a problem that the compiled shader completely ingnores lighting from the light sources on the scene. Here's the code: ...
2
votes
2answers
25 views

Derive direction in which a spot light emites its light from a projection matrix

First of all, sorry if my question sounds too basic or even makes no sense. I'm new with game development I'm working with HPL1Engine, specifically, the lights parts. I need to know the direction in ...
0
votes
0answers
60 views

Cast shadow without rendering object

I'm new to UDK, and am using it to develop a survival-horror game based heavily on shadows. My question is short: is there a way to create an actor that, when rendered, ONLY renders its shadow (not ...
0
votes
0answers
24 views

Unity3d: Lines in Android build

I have a directional light pointing at the 3d objects. For some reasons, when I build to Android, the lighting produces multiple horizontal lines. It does not happen in other builds such as the ...
2
votes
0answers
67 views

Surface shader with VertexLit causes black object

I wrote the simplest possible surface shader: Shader "SimpleSurf" { Properties { _MainTex ("Base (RGB)", 2D) = "white" {} } SubShader { Tags {"RenderType"="Opaque" } ...
1
vote
0answers
72 views

Unity : shader that uses mesh.uv to tile texture atlas and mesh.uv2 to tile light atlas

I'm using a texture atlas and a light atlas to tile a mesh. I have the texture atlas working fine. I can apply textures and create a sort of tile map on my coded mesh. At the moment I'm using the ...
1
vote
2answers
133 views

Voxel Lighting in Unity3D

I'm working on a Voxel project in Unity3D for fun and learning. I've been reading up on how this is done and have implemented a simple Voxel map in my project. My question is about the lighting. I've ...
2
votes
2answers
86 views

How can I calculate spotlight lighting in Vertex/Fragment shader in Unity?

I've written a vertex/fragment shader for my game. It uses 3 textures and represents a floating water on the wall (so I have 1 texture for water, 1 for geometry and the last one is mask) so it looks ...
1
vote
2answers
113 views

Technique for multiple shadow casting lights in 2D

I'm trying to create shadows in a 2D game in such a way that I can have an arbitrary number of lights in a scene, all of which can cast shadows. To do this I think I have to generate a mesh for each ...
1
vote
2answers
84 views

pre-rendering light on texture based on bump map

Using a gray-scale bump-map and N sources of colored light, what is the algorithm to render the light on the textured surface, assuming I have the angle(s) and distance of each light source? (I am ...
1
vote
2answers
133 views

Can global Illumination via path tracing replace all other current lighting techniques?

In the sense that you currently have algorithms like HDR, shadows, reflections, caustics, motion blur and so on, does complete path tracing take care of all these effects, or would you still have to ...
0
votes
0answers
39 views

VertexColor shader is not working correctly in built application

I want to change the vertex colors of my mesh. The light sources must not affect the objects with this shader, its lighting must be determined only by its vertices colors, so I turned the Lighting ...
0
votes
0answers
25 views

ColorMaterial:AmbientAndDiffuse equivalent for CG\HLSL

I have this shader written on shaderlab, which replaces Ambient and Diffuse values of the material, because I need to tweak vertices colors from the script. Shader "VertexSimple" { Properties ...
2
votes
2answers
192 views

How can I support many point light sources in a dynamically-generated level in Unity?

I'm currently working with a dungeon game which is similar to Dungeon Keeper by Mythic Entertainment. I'm using Unity and developing this game for Ipad 2 and above. Player can modify his dungeon, and ...
2
votes
2answers
130 views

Where should shaders and lights be in a component-based entity system?

Where should I put the shader and the light / shadow calculation? Should that be a component too? And should the rendering system know how to handle them or should there be a separate light system? ...
1
vote
4answers
213 views

Cell Lighting Propagation Problem

I have in place a cell-based lighting system that works basically like this: (Not my actual code) //Light moves up for (int x = 0; x < width; x += 1) { for (int y = 0; y < ...
2
votes
1answer
123 views

2D lighting causes black rings to appear

A year ago I implemented 2d lighting in XNA using sprites. The sprites I used were created by placing a soft white photoshop brush on a transparant background. The result was this: (lights only) ...
1
vote
1answer
78 views

Can you export lighting models directly from 3D application to a real time renderer?

is it possible for example to insert lighting in a 3D Model software like 3DSMAX and export an animated model like md5,..etc. and export the lighting too ?
1
vote
1answer
214 views

How can I calculate a terrain's normals?

Im trying to implement basic lighting in Opengl 3+ (a sun) with this tutorial : http://www.mbsoftworks.sk/index.php?page=tutorials&series=1&tutorial=11 Im building a basic terrain and its ...
6
votes
1answer
137 views

Reducing Spherical Harmonic Ringing

I've generated some 2nd order SH light-probes from cube-maps in my scene and I was surprised how strong artifacts are around the back of the dominant lights. I switched to a Lambert source plus ...
0
votes
2answers
380 views

Simple 2d tile based lighting in xna

I am currently trying to implement simple lighting into my game. My world is represented in a 2d array of numbers, each number being a certain tile. I am changing the color parameter in the ...
2
votes
2answers
187 views

Shadow mapping with directional light?

I'm doing shadow mapping in my OpenGL 4.3 deferred renderer, and I'm starting with directional lights believing it to be the easiest. What I do not understand is how the view projection matrix is to ...
6
votes
3answers
472 views

How can I create a shader that will reproduce this lighting effect on terrain?

Notice the way in which the major light source in each image reflects off the ground, as a function of the distance between the light source and the viewer (?). Is this a (bumped) specular map? ...
1
vote
1answer
203 views

Lighting Covering Up Sky ( XNA / C# )

I have a 2D tile-based lighting system which is drawn onto a Render Target. I am also drawing a background which involves mountains, sun/moon, and clouds. There is also the unlit game; blocks, ...
0
votes
0answers
42 views

Simultanious RenderTarget use in XNA

I am currently grappling with the idea of lighting a 2D scene as a 3D one and i need to clear up a couple of things. I have so far figured out that i am going to use a differed lighting system where ...
1
vote
1answer
100 views

What causes still objects have lines in them when lighting is being changed? [duplicate]

First, here is what I'm talking about (I changed the contrast to make it more visable, since it's not really visible in still images): Ingore the chat box, I was spamming buttons to see which one ...
1
vote
1answer
131 views

Spot and area lights inconsistent

Im having problems with area light and spotlight. When adjusting parameters the change is not consistent and sometimes the light grows tstronger and then dissapears and then reappears very strong, ...
4
votes
1answer
801 views

Faking 2d light using shader (Unity, Shaderlab)

Since the concept was difficult to explain in words for someone who's not quite familiar with shader, I described it in pictures. I'm currently using Unity and it seems Shaderlab is the best choice ...
0
votes
1answer
77 views

Blending and shadowmapping?

I am trying to implement shadow mapping, and currently I have 2 point lights and 1 global ambient light source and my rendering loop looks roughly like this (the details are not relevant): void ...
1
vote
1answer
117 views

Flashing candle light

What is a simple way to simulate flashing candle / torch / fire light? I'm not asking about animating the flames, I'm only interested in the light surrounding the fire, similar to what this device ...
2
votes
1answer
142 views

Are ambient, diffuse and specular light or material properties?

Are ambient, diffuse and specular properties of light or material? I am doing ray casting in OpenGL, I've managed to create lit sphere using formula I = L Ka + L Kd (n . l) + L Ks (r . v)^n but I ...
1
vote
0answers
31 views

Implementing Light Volume Front Faces

I recently read an article about light indexed deferred rendering from here: http://code.google.com/p/lightindexed-deferredrender/ It explains its ideas in a clear way, but there was one point that ...
0
votes
1answer
123 views

fragment shader directional light positioning with camera

Im trying to set up directional lighting in the fragment shader. So the direction of my light moves with the camera position. #version 150 core uniform sampler2D diffuseTex; ...
6
votes
2answers
268 views

Spherical harmonics lighting - what does it accomplish?

From my understanding, spherical harmonics are sometimes used to approximate certain aspects of lighting (depending on the application). For example, it seems like you can approximate the diffuse ...
1
vote
1answer
101 views

HLSL What you get when you subtract world position from InvertViewProjection.Translation?

In one of NVIDIA's Vertex shaders (the metal one) I found the following code: // transform object normals, tangents, & binormals to world-space: float4x4 WorldITXf : WorldInverseTranspose < ...
2
votes
1answer
181 views

Incorrect lighting results with deferred rendering

I am trying to render a light-pass to a texture which I will later apply on the scene. But I seem to calculate the light position wrong. I am working on view-space. In the image above, I am ...
1
vote
1answer
253 views

Grid-Based 2D Lighting Problems

I am aware this question has been asked before, but unfortunately I am new to the language, so the complicated explanations I've found do not help me in the least. I need a lighting engine for my ...
8
votes
1answer
263 views

Fast lighting with multiple lights

How can I implement fast lighting with multiple lights? I don't want to restrain the player, he can place an unlimited number and possibly overlapping (point) lights into the level. The problem is ...
0
votes
1answer
362 views

Directional light causes an FPS drop

I have only one object in the scene and it is lit with a directional light. It uses the mobile/diffuse shader. The issue is that on iPhone 4 the FPS drops from ~42FPS to ~11FPS when the directional ...
2
votes
1answer
257 views

Compute Shader Memory Sharing

Ok guys I have had some pretty good success on this site but I feel that this is a pretty complex question. I am trying to do tile based deferred lighting using DirectX 11 and the compute shader. ...