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

learn more… | top users | synonyms (1)

5
votes
2answers
595 views

How many OpenGL programs should I use to render multiple objects?

My scene has multiple objects in it. (Let's say 3 cubes, 1 cylinder, 8 spheres.) I assume I should create a vertex shader for each. How many programs should I have? Alternatives: One program per ...
1
vote
1answer
316 views

glsl shader to allow color change of skydome ogre3d

I'm still very new to all this but learning a lot. I'm putting together an application using Ogre3d as the rendering engine. So far I've got it running, with a simple scene, a day/night cycle system ...
1
vote
1answer
46 views

Lookup table in shader opengl es

What I need is apparently very simple, a lookup table in a fragment shader. It seems that the natural way would be an array float lut[], but in some implementations of OpenGL ES I am getting an error ...
16
votes
3answers
1k views

Why is H (blinn) used instead of R (phong) in specular shading?

I can't find a good reason for this anywhere. The reflection vector used in phong has a simple basis in physics. But the half vector used in blinn seemingly has no rational basis, and does not ...
0
votes
0answers
19 views

Shader | Special Effect - Unit selection [duplicate]

I would like to know how the shaders used to show which unit is selected are made. Here is an image to illustrate. How the merge effect of the blue circles can be achieved ? I didn't found any ...
0
votes
1answer
105 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 ...
1
vote
1answer
47 views

Using depth texture for depth testing

I was wondering if it is possible to render my scene onto a depth texture then using that texture for depth testing in another pass. I have an idea to that in shaders, but is that possible ...
0
votes
0answers
62 views

Gaussian blur not working correctly

So pretty much I tried to add a gaussian blur to something I am making and it is acting oddly. The setup is like: [All framebuffers are cleared to rgba(0,0,0,0), normal blend enabled] Draw some solid ...
0
votes
0answers
29 views

Problems with drawing billboards [closed]

I am currently trying to draw billboards and some geometry with "modern opengl approach". Problem is that I cannot force billboards to keep their positions in space. I need to link text positions ...
1
vote
0answers
89 views

How to implement efficient Fog of War?

I've asked a question how to implement Fog Of War(FOW) with shaders. Well I've got this working. I use the vertex color to identify the alpha of a single vertex. I guess the most of you know what the ...
0
votes
1answer
48 views

Proper way to encapsulate a Shader into different modules

I am planning to build a Shader system which can be accessed through different components/modules in C++. Each component has its own functionality like transform-relevated stuff (handle the MVP ...
2
votes
1answer
171 views

How do I use unpackHalf2x16?

I'm trying to use (un)packHalf2x16, without success so far. I'm drawing with: glVertexAttribIPointer(0, 2, GL_UNSIGNED_INT, 0, 0); glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vbo); ...
-1
votes
0answers
13 views

cocos2d-x simple shader usage [closed]

I want to obtain color ramp effect from this tutorial: http://www.raywenderlich.com/10862/how-to-create-cool-effects-with-custom-shaders-in-opengl-es-2-0-and-cocos2d-2-x Here is my code in cocos2d-x ...
2
votes
2answers
136 views

How to implement Fog Of War with an shader?

Okay, I'm creating a RTS game and want to implement an AgeOfEmpires-like Fog Of War(FOW). That means a tile(or pixel) can be: 0% transparent (unexplored) 50% transparent black (explored but not in ...
0
votes
1answer
118 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 ...
0
votes
0answers
16 views

XNA `tex2Dlod` always returns transparent black

I want to sample a texture in a vertex shader, so at first I just tried using float2 texcoords = ...; color = tex2D(texture, texcoords); But apparently I cannot use tex2D in a vertex shader, and ...
0
votes
2answers
28 views

Material tiling and offset in unity

Ambiguity: What exactly is the difference between Tiling the material and Offset of material? Need to do: I need the material to be repeated n times on the object where I need to set the value of n ...
1
vote
0answers
39 views

Multi Pass Blend

I am seeking the simplest working example of a two pass HLSL pixel shader. It can do anything really, but the main idea is to perform "ping ponging" to take the output of the first pass and then send ...
0
votes
0answers
13 views

OpenGL textures trigger error 1281 if SFML is not called

I am using SOIL to apply textures to VBOs, without textures i could change the background and display black (default color) vbos easily, but now with textures, openGL is giving an error 1281, the ...
12
votes
5answers
188 views

How to make unit selection circles merge?

I would like to know how to make this effect of merged circle selection. Here are images to illustrate: Basically I'm looking for this effect: How the merge effect of the circles can be ...
1
vote
1answer
94 views

XNA Diffuse Shader Issue. Edge lighting problem. Image Attached

As you can see in this image the diffuse shading is working correctly in some places but in other places such as the the bottom of the sphere you can see the squares/triangles of the mesh. Any ...
1
vote
1answer
42 views

Problems with texture orientation in space

I am currently drawing texture in 3D space and have some problems with it's orientation. I'd like me textures always to be oriented with front face to user. My desirable result looks like ...
1
vote
1answer
134 views

Render 2 images that uses different shaders

Based on the giawa/nehe tutorials, how can I render 2 images with different shaders. I'm pretty new to OpenGl and shaders so I'm not completely sure whats happening in my code, but I think the shaders ...
1
vote
0answers
23 views

HLSL: An array of textures and sampler states

The shader must switch between multiple textures depending on the Alpha value of the original texture for each pixel. Now this would word fine if I didn't have to worry about SamplerStates. I have ...
-1
votes
1answer
333 views

Using Shader causes triangle to disappear

The following is my rendering code. Private Sub GameRender() GL.Clear(ClearBufferMask.ColorBufferBit + ClearBufferMask.DepthBufferBit) GL.ClearColor(Color.SkyBlue) ...
1
vote
0answers
63 views

OpenGL - Cascaded shadow mapping - Texture lookup

I'm trying to implement cascaded shadow mapping in my engine, but I'm somewhat stuck at the last step. For testing purposes I've made sure all cascades encompass my entire scene. The result is ...
4
votes
1answer
126 views

PCF shadow shader math causing artifacts

For a while now I used PCSS for my shadow technique of choice until I discovered a type of percentage closer filtering. This method creates really smooth shadows and with hopes of improving ...
-1
votes
1answer
31 views

Is lighting different from Immediate mode rendering to VBOs?

I recently got a textured cube to render as a VBO, and I've noticed some strange things as I have been trying to incorporate lighting. Firstly, there is no difference if I comment out any lines ...
7
votes
1answer
142 views

Slow uniform array in shader causing FPS drop

I'm trying to use an uniform array of matrices in my compute shader. However, it's really slow. I've narrowed it down to this lines of code: uniform mat4 someMatrixArray[64]; ... vec4 result = ...
-2
votes
1answer
68 views

Texture Stretching on VBO cube

I'm using JOGL and I'm trying to render a textured VBO cube with glDrawArrays. The cube renders, but the texture is stretched and stripy as seen in the picture above. It seams that changing my ...
3
votes
1answer
312 views

Spritebatch Vertex shader world matrix change after each draw

I have a spritebatch where I draw some textures transformed in 3d space. The easy way was just Begin with the transformation matrix, draw, and end it right after. But that is silly, so I'm trying ...
1
vote
1answer
50 views

Replace each white spot of image to radial gradient

Recently, I have read article about sun shader (XNA Sun Shader) and decided to implement it using OpenGL ES 2.0. But I faced with a problem connected with shader: I have two textures, one of them is ...
0
votes
1answer
150 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
22 views

Rendering a mesh in image viewport

I have a mesh made of nearly half to a one million vertices. I also have some 6-DoF camera poses around this mesh. At these poses I'd like to find out which of the 3D points of this mesh get projected ...
2
votes
2answers
111 views

Water silhouette shader using GLSL

I have this problem to solve using Cocos2d-x 3.x: In my game there is water represented by rectangle texture, modified by the code on the go. I also have a character moving around, rotating etc. I ...
0
votes
1answer
28 views

How to texture a VBO?

I'm not sure which way is the best way to do this for my purposes. My purposes being having a textured (with an image) cube. Also, I've been following a blend of tutorials, so I'm not sure which ...
0
votes
1answer
38 views

HLSL Pixel Shader Sematics

I have a HLSl pixel shader that I'm using to create a deferred buffer, I have simplified the code to show you: struct PS_INPUT { float4 PosWVP : SV_POSITION; float4 ...
1
vote
1answer
46 views

Unity, shader, vertexID

I'm writing a shader and I just wanna ask if it's possible to get the ID of the vertex that is currently being manipulated. I read something about gl_vertexID, but I couldn't find out if that is ...
1
vote
2answers
74 views

Should I shade models before or after importing them into Unity?

Is it better to shade a model inside the 3D modeling software or inside Unity? As an example, if I need to use a transparent model, should it be made transparent inside the modeling application or ...
0
votes
0answers
44 views

How to pass a custom array of data to a shader

I want to know how to pass an array of data (it will be an encoded map, actually) to the fragment shader so I can query it as an array. AFAIK this is sadly not implemented in unity, so I'm looking ...
0
votes
1answer
207 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 ...
10
votes
1answer
1k views

How do Raymarch shaders work?

I have been looking at shaders found here shadertoy.com and most of the cool ones have noise and raymarch in common. I do not understand the source code at all but I really want to. How do these ...
1
vote
2answers
123 views

GLSL to Cg: why is the effect different?

With reference to this question, where I was trying to make the shader compile, I am now trying to make an effect appear. The effect can be shown here, through a GLSL shader: But when I use the ...
5
votes
2answers
295 views

How can I optimize a parallax effect consisting of multiple transparent layers?

I have a parallax effect in MonoGame consisting of multiple semi-transparent layers of textures. The effect is simple, but rendering multiple transparent layers on top of each other is rather slow. ...
0
votes
0answers
72 views

OpenGL shading doesn't work with different projection and view matrices?

I found an online (public-domain) code to do marching cubes, and I am trying to adapt this code to work in my own project. The code uses GLUT and "older-style" OpenGL, whereas I am using GLM and ...
0
votes
1answer
78 views

GGX energy conservation

I´m trying to implement a microfacet BDRF with GGX density function in my renderer. I have read almost all the papers out there in the last week, and I have a bunch of equations that should work fine, ...
12
votes
4answers
18k views

Fastest way to draw quads in OpenGL ES?

I am using OpenGL ES 2.0 I have a bunch a quads to be drawn, would love to be able to have to pass only 4 vertices per quad as if I were using GL_QUADS, but basically I just want to know the best way ...
1
vote
1answer
152 views

OpenGL and atlas

I'm trying to draw element from a texture atlas with OpenGL ES 2. Currently, I'm drawing my elements using something like that in the shader: uniform mat4 uCamera; uniform mat4 uModel; attribute ...
0
votes
0answers
35 views

Barycentric vertex coordinates in GLES 2.0

I have a certain set of polygons, which are stored in a vertex buffer and an index buffer. The polygons are textureless and normalless. The polygons are dynamic, their buffers get constantly emptied ...
0
votes
2answers
169 views

OpenGL UseProgram() fails

I have a rather strange exception on my application using OpenTK on Linux (ArchLinux with Mono 3.2.8) with GL.UseProgram(). I wrote a class to combine multiple files to one program: public sealed ...