Tagged Questions

a computer program that runs on graphics hardware and provides a high degree of control over how scenes are rendered

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0
votes
1answer
115 views

Merging several textures into one using RGB channels

Would it be possible to place a texture into each RGB channel? Example: Red = wood.png Blue = tiles.png Green = metal.png The advantages I could see are saving space, memory and draw calls and the ...
2
votes
1answer
109 views

Is it ok to mix shader types?

The title might not be precise. Let's say I have one material consisting of vertex and pixel shader, another one consisting of vertex, geometry and pixel shader, and yet another one consisting of ...
1
vote
1answer
148 views

Blinn, Normal maps & Fresnel?

So something came up today when I was going over my Blinn shader. As I've been taught, the half-angle vector is calculated in the fragment shader, and is equal to normalize(lightDir + viewDir). This ...
0
votes
0answers
93 views

Finding the correct transformation in vertex shader for easy sprite drawing

Before we begin the question: Here are the necessary meta information: I want to use JOGL / OpenGL to create a library that is only, and I repeat only, able to draw and manipulate 2D sprites on a 2D ...
2
votes
1answer
391 views

Alpha Blending: use the pixel with the smallest alpha

I'm writing a transparency shader where I need any intersecting textures to, wherever they overlap, take the texture pixel with the smallest alpha value and render only that, discarding the other ...
0
votes
1answer
140 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: ...
0
votes
2answers
154 views

Rendering terrain only with GPU

This is not about generating plane geometry and then applying a shader on it. Instead, I want a big single flat plane, then apply a shader on it. The vertex shader has a uniform vec3 ...
3
votes
1answer
126 views

Using normals in DirectX 10

I've got a working OBJ loader that loads vertices, indices, texture coordinates, and normals. As of right now it doesn't process texture coordinates or normals but it stores them in arrays and creates ...
0
votes
1answer
135 views

How to change colors of texture in lwjgl? [duplicate]

I have the following texture: The black pixels are characters, the background is transparent. How do I change the black pixels of the characters to another color? I use this texture as a bitmap for ...
10
votes
2answers
1k views

Refractive glass shader

I have an infinite hexagonal floor, generated by tessellating a point grid in a tessellation shader pair: Note that this is a flat wireframe - the "shadows" are a lighting trick: Now, I'd like ...
2
votes
2answers
229 views

Does GLSL copy function arguments by value?

My question is about passing variables to GLSL shader. I'm not sure how that works and what are the performance implications. Say I got a function that accepts a "vec4" variable. The question is - is ...
1
vote
0answers
284 views

How can I combine my scrolling effect with the vertex lit shader?

I want my shader to work in both Forward and VertexLit rendering modes. I'd written a texture scrolling shader, but I also want to consider lighting which is produced by Vertex lit shader. I can't add ...
2
votes
0answers
436 views

Normal mapping does not work correctly using GLSL and OpenGL [closed]

Hello I wrote a simple OpenGl program using GLSL to render a simple uv mapped plane using the normal mapping technics. Here's the display with a simple phong shading (without normal mapping) : Now ...
9
votes
3answers
1k views

Is multitexturing really just “using more than one texture”?

This might seem stupid, but it bugs me. From what I understand, multitexturing is just using more than 1 texture per shader (usually to blend them somehow). So instead of creating 1 texture, I create ...
2
votes
1answer
260 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" } ...
2
votes
1answer
636 views

How to outline a 3D object with a cartoon style stroke? [duplicate]

How could I draw (stroke) the outline of a 3D object in a cartoon style with GLKit? I'm referring to something like this: However we can start with a simple line around the object and then try to ...
0
votes
1answer
145 views

How do I pass an object location into a vertex shader?

I am using Blender Game Engine. I want to create a large flat plane, and deform it locally near a moving object. So far (despite being a beginner at shaders) I've written a vertex shader for the ...
2
votes
2answers
408 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 ...
0
votes
1answer
162 views

XNA and HLSL shaders - Instancing using World Matrix array

I have posted this question on StackOverflow and was directed here, so I'll just copy the question: I am attempting to improvise some sort of hardware instancing in my game. I wish to draw multiple ...
3
votes
1answer
78 views

Why does my PixelShader ignore color but respond to alpha changes?

I started teaching myself some DirectX a short time ago and found something I'm confused about. For some reason, I can only get the color of the model I'm drawing to vary between black and white, ...
5
votes
3answers
632 views

How do I send multiple matrices to a vertex shader?

I'm practising animations using bones/skinning. I am trying to send the shader one matrix per vertex. I can think of these two approaches. Method 1 I have one uniform handle for each bone matrix ...
0
votes
0answers
71 views

Minimum/maximum depth of tile in OpenGL

I'm trying to implement tiled deferred rendering, but I'm stuck on calculating the min/max depth for each tile. I'm using compute shader for this. This is my shader code: #version 430 #define ...
2
votes
1answer
164 views

How to work with smaller intermediate textures in OpenGL and GLSL?

I'm working on a project rendering water simulated through smoothed-particle hydrodynamics (SPH) with a non-photorealistic look to use in games. In the actual stage of the project everything about ...
0
votes
1answer
142 views

Strange behaviour using VAO (OpenGL 4.0)

I want to display a simple textured Monkey mesh using VAO. Here's the code in the render part first without VAO to see what is the result I'm looking for. Texture *pTexture = ...
0
votes
1answer
194 views

translate-scroll repeated 2d texture using opengl shader

I managed to implement an infinite 2d texture scrolling using the following shader. btw I'm using cocos2d-x 2.2.1. The vertex shader: attribute vec4 a_position; attribute vec2 a_texCoord; #ifdef ...
0
votes
1answer
268 views

Using Appendbuffers in unity for terrain generation

Like many others I figured I would try and make the most of the monster processing power of the GPU but I'm having trouble getting the basics in place. CPU code: using UnityEngine; using ...
1
vote
0answers
156 views

How to fix problem in serpentine case using Blinn/Loop algorithm

I'm trying to implement Blinn/Loop algorithm to render cubic bezier on shader. I calculate the curve type using code below (v0, v1, v2, v3 are cubic bezier segment): CurveType ...
1
vote
1answer
91 views

SetFloat() in HLSL shader (effect) has no effect - variables stay at 0

I have a problem wherein I'm trying to set two simple float variables in my shader. I have a dozen other shaders in this project where it works fine, but for some reason, I've got a bug in this one ...
1
vote
0answers
1k views

How can I get this Shader for Unity working with Normal maps? [closed]

So I'm by no mean a shader coder, but I've been hacking around the last few days trying to get working a shader for the sprites of the skeletal animation tool Spine in Unity that can properly use ...
1
vote
1answer
90 views

Use of the xyY color space?

What's the use of the xyY colorspace in games? I'm not sure what's the advantage of using it in shader programming or elsewhere.
1
vote
1answer
152 views

Draw character silhouette when not visible

I have a mesh representing my character. I want to give it a partially transparent greyish silhouette when other objects are blocking it from view of the camera. I'm using Ogre3D, and GLSL as a ...
3
votes
1answer
806 views

Issue with interpolation on a burn shader (lerp and smoothstep)

I'm trying to create a simple burn shader. See here for more info on the method I'm using. However, I don't get why replacing the smoothstep with a lerp results in completely different results. Am I ...
1
vote
0answers
264 views

Shadow mapping implementation not working? [closed]

I am trying to implement Shadow Mapping in my program using Java/LWJGL/OpenGL/GLSL, but I cannot get it to work properly. Let's start off with a screenshot first, then the relevant code and lastly ...
0
votes
1answer
232 views

Textures not displaying. Problem with fragment and vertex shaders

Hi i have newbe question. I am sending to gpu textures unit and they dont display. This is simple version of my fragment and vertexshader. (More complicated version also dont work with other textures ...
0
votes
2answers
154 views

Manage shader parameters

I'm making some test with OpenGL and I've got a problem with my application design. Currently, I've got something like that in pseudo code: // Ask to draw a given scene. renderer->drawScene( ...
1
vote
2answers
148 views

Bilinear filtering: Selecting pixels to interpolate between

When looking for implementations of bilinear filtering online, all the ones I can find seem to just pick the current pixel, and the three pixels to the bottom and right side of the current pixel. ...
1
vote
1answer
106 views

recommended shader pipeline infrastructure in core opengl 3.3

I am writing a game project in Go and I am using an OpenGl 3.3 core context to do my rendering stuff. At the moment I have different types of renderers. Each renderer has it's own pair of vertex- and ...
0
votes
2answers
190 views

How to mix pixel colors in Shader?

I have a pixel that have a colour RGB. This color is calculated by the shader and can be anything. How can I override this color by a colour I choose. If my pixel is white it's simple, I can do this: ...
0
votes
1answer
143 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 ...
2
votes
2answers
366 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 ...
0
votes
1answer
519 views

Simple curiosity about glDrawElements function

I've written a very simple OpenGL program displaying a white cube. To do the job done I recovered vertex position and indice data from an OBJ file that describes my cube. Here's the OBJ file content : ...
2
votes
2answers
234 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
1answer
160 views

Starting with shaders and particles

I'm working on a flow field with particle systems and starting to learn about shaders in three.js. Current state of my work is available here. As such amount of calculations is quite heavy for a big ...
2
votes
2answers
2k views

2d metaballs with shader to give blobs of water effect?

I want to simulate blobs of water in a 2d game in Unity3d. One possible way of doing it is to use 3d metaballs moving in a 2d plane though this is very processor intensive. Do you think it would be ...
0
votes
1answer
129 views

How to share matrix in HLSL?

I am trying to share this across multiple effect files: matrix worldMatrix : register(vs_4_0, b0); If I set this from one effect file, will it effect every effect file which has the same type of ...
9
votes
3answers
811 views

How can I create a glitter effect?

I am trying to create a glittering effect for my realtime shader but I don't know how. Here is one example, and another example. What technique can I use to implement this?
0
votes
0answers
307 views

How does this bezier curve rendering shader determine if a curve is concave or convex?

I have read an article about rendering quadratic splines on a GPU with a shader. The algorithm is explained like this: For each quadratic Bézier curve we use Bézier control points of the curve to ...
6
votes
1answer
255 views

Should the Oj lobe of a Lafortune shader cause the light to be displaced?

I implemented the Lafortune shader in WebGL, and my biggest concern is about this formula: Explanation Kd/Ks is the material diffuse/specular color, ρd/ρs is the light diffuse/specular ...
2
votes
1answer
116 views

Light Space and Light Texture Space in shaders

I'm looking into material translucency and I'm working through some GPU Gems documentation (http://http.developer.nvidia.com/GPUGems/gpugems_ch16.html). In Example 16-4 it references matrices for ...
1
vote
1answer
62 views

Does `SetResourceArray` copy the data into the GPU?

I am trying to create multiple textures, and only several of them change every few frames. I don't want to have to copy in the whole array via SetResourceArray for just a few textures that change, ...