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Questions tagged [opentk]

OpenTK is a C# library that wraps OpenGL, OpenCL and OpenAL.

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13 views

C# NanoVG Transparency issue

Hi I'm trying to change from Cairo (2D Vector image library) to NanoVG. I'm using C#, openTK and Nano.VG.NET to make my game. I'm having issues with alpha? Transparency/Blending is an issue… Here ...
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1answer
33 views

uniform matrix not being assigned to shader

im trying to apply a rotation matrix to my shader and when i try to set it and mult it in the shader my triangle doesn't render my drawing code: ...
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0answers
25 views

White shadow map

I am implementing the shadow map with OpenTK and c#, I do everything as expected but I always got a white shadow map if I render it to a quad. First I initialize the frame buffer object ...
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1answer
233 views

Multiple glControl on same winform is not working - OpenTK C#

I have to show frames from two cameras in two openGl control separately at same time. For that I have put two opengl control in my form and pass those frames to opengl accordingly. But when running ...
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1answer
117 views

OpenGL frustum extraction

I'm trying to extract frustum planes from the camera. The algorithm is simple: create clip to world space matrix (inversed projection * inversed view) multiply clip point by clip to world matrix ...
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1answer
83 views

OpenTK OpenGL wierd camera look

I am trying to implement a simple camera mouse look. ...
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0answers
165 views

Greedy Meshing : Slow to rebuild when updating chunk

I've a problem with my voxel based game. The game is sliced into chunks (Like Minecraft), each chunk is 16x256x16 blocks. When I started the project, I used a basic culling system when hidden blocks ...
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1answer
88 views

OpenGL Texture from Raw Data Not Rendering Correctly

Starting off the class in question is here: ...
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0answers
31 views

How to fix 3D AABB Collision not working on corners?

I'm currently working on a minecraft clone and right now trying to implement player to terrain collision. My approach is to get the blocks which the player might collide with through the collision box ...
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1answer
65 views

How can I load a texture from VBO?

I already have the .png file in my project, and the .png file has the "Embedded Resource" and "Do not copy" settings. The game runs fine - nothing throws an error, but the game does not show ...
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1answer
758 views

How do I enable FSAA in OpenTK?

All I could find about it is this question, but GraphicsMode alone doesn't enable anti-aliasing: ...
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3answers
353 views

Multiple rendering back ends architecture

so I've been thinking about designing a rendering engine with multiple back ends in C#. Well, let me rephrase; I wish to design an engine that can be easily extended upon to support multiple back ...
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1answer
432 views

OpenTK Terrain - Triangle strip issue

I'm currently trying to render terrain in an OpenGL application I'm making (using OpenTK in C#). Something really odd is happening and I'm not sure why. Here is the code I use to load my terrain from ...
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1answer
766 views

Read from OpenGL texture to Bitmap in C#

I want to read a texture pixels from texture id (associated with some FBO) to bitmap object in opengl (opentk) in c# But it throws an exception says: ...
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0answers
250 views

OpenTK Camera Rotation issue [duplicate]

I'm currently developing a 3D game engine in C# using OpenTK. I have basic game objects, and each game object has transform (translation, rotation and scaling). A game object can have components (...
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3answers
268 views

The largest vector in an array

I'm working on a game engine in C# at the moment and I've come across a matter I find confusing. I need to know how to get the maximum three component vector in an array. There is a method in OpenTK ...
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2answers
98 views

Multiple Indices Problem

Recently, I've been trying to use COLLADA files in OpenGL. The problem that a lot of people before me have run into is COLLADA's ...
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1answer
233 views

OpenGL scissor odd behaviour

I am currently developing a GUI app using OpenGL with OpenTK as interface in C#. The viewport is set to the entire window space (0,0,width,height) and an ortho transformation is applied like this: <...
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1answer
4k views

Should I use retained mode or immediate mode

I'm trying to make a opengl wrapper for winforms(.net). Basically you code in gdi+ syntax but it gets rendered for opengl(using glcontrol of opentk). Which mode should I use for rendering ui? It has ...
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1answer
660 views

Incomplete rendering using OpenTK (VBO)

Using Assimp.net I did load obj file. assimp returns back Mesh object that contains vertexes, normals, faces, colors and texture. when I don't use VBO the object will load complete. like this : But ...
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2answers
449 views

2D HUD over 3D scene

I'm trying to create a 2D Heads up Display for my players in a 3D OpenTK environment. How I'm doing it is by drawing my 3D elements and then running this code. ...
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0answers
81 views

Cube Translation Looks All Wrong

I'm making a very simple cube in OpenTK and it seemed to be going fine until I tried to move it around. Moving it along the X Axis seems to elongate the cube, not the result I hoped for. My Vertex ...
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0answers
27 views

GL.BlendFuncSeparate(ArbDrawBuffersBlend) Enum has no members?

I want to use the function GL.BlendFuncSeparate but it seems that one of the enums used has no members. public enum ArbDrawBuffersBlend { } Is ...
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0answers
649 views

Rotating an object around it's centre in OpenGL

I'm writing small 3d viewer of models from .obj file. I have a car and I want to rotate car's wheels. I found a lot of good examples but I still have a problem: wheel rotates around point at the it's ...
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1answer
732 views

What's the DSA version of glTexImage2D?

I want to set the initial data of a texture in an OpenGL 4.5 program (using OpenTK.Next and .NET), utilizing the new Direct State Access methods. However, I cannot find a DSA version of ...
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1answer
111 views

Shader or No Shader?

I have a question about something I don't really understand. In OpenTK, should I have shaders? Is it frowned upon not to? What are the pros and cons of having shaders? Can I go perfectly fine without ...
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1answer
147 views

VBO Performance issues

I'm making a 2D Tile based game in OpenTK at the moment. Performance was really bad (laggy and slow) with direct drawing, so I switched to VBOs. The performance hasn't changed, it might even be slower ...
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2answers
372 views

How to use texelFetch

I'm trying to switch from using the GLSL texture() function in my shader to using texelFetch() because I want very little ...
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0answers
389 views

Enabling OpenGL lighting seems to disable blending

I have the following code to set up for some 2D drawing using OpenTK. I originally wrote it without any lighting considerations, but later added the lighting block. This version of the code uses ...
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1answer
133 views

glClearBuffer takes 1 second on a Geforce 9500GT

These 2 lines (in C# using OpenTK) seem to cause 1 second lag every frame on a machine with a Geforce 9500 GT ...
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1answer
406 views

Draw wrong faces in obj model with OpenGL VBO

I am trying to draw a 3D model from an .obj file, and have met big trouble. I think my model draws with wrong faces, but I can't understand why. Original model: This is my code for reading the ...
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1answer
248 views

Vertex Skinning, Bone matrices question

I'm creating a model/animation viewer in C# using OpenTK for a game's models. Before stating my problem I want to describe a bit what I've accomplished so far in case I'm fundamentally missing ...
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1answer
584 views

glUniformMatrix4fv OpenTK equivalent

Very simple and quick question which surprisingly I couldn't find an answer to over the internet: what is the equivalent of glUniformMatrixfv for opentk? I've browsed all the 7 overloads of GL....
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2answers
523 views

Trying to implement forward rendering in OpenGL

I'm working on implementing forward rendering in my 2D engine, as far as I'm aware everything should be set up correctly, I've ran into some issues earlier but I'm sure I've fixed those at this point. ...
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1answer
8k views

C# OpenTK Text rendering

I've been looking everywhere for a solution on how to render/draw text for my 2D OpenTK-based game. Been trying quite a few QuickFont ones without success (either a AccessViolation exception or text ...
2
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1answer
666 views

Opentk hdr rendering with framebuffer white screen problem

I am trying to do hdr rendering with two shader programs: one simply draws a hdr texture on a fullscreen quad and the other one does tonemapping. I am trying either linear tonemapping ...
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2answers
711 views

Opentk Textured Full Screen Quad

I want to display a texture on a full screen quad. What I get is a completely green quad and after a week of debugging I cannot understand why. I am currently using OpenTK 1.1.2225 and Magick.NET-Q16-...
3
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1answer
372 views

Turning On/Off Vsync no longer working when rendering to an offscreen buffer

I have this reaallly strange issue that as soon as I render to an offscreen framebuffer I am no longer able to toggle VSync while my application is running. I am using OpenTK as the opengl wrapper, ...
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0answers
1k views

How to use OpenTK (OpenGL) with MonoGame?

So I've been making a snake game using MonoGame (DirectX Only). I added movement, controls, feeding and growing in length. I wanted to add smooth animations to the game because the snake is just made ...
2
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0answers
132 views

GL.Scissor not working as expected

I have some code for rendering a button in an application and I want to clip the text if it's wider than the button itself. Here a bit of code to describe what I'm doing: ...
2
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1answer
286 views

OpenTK crashes with Mono

I've implemented OpenTK as a secondary renderer which would let me support Mac/Linux only to realize that for some reason, even without any modifications (new MonoGame project), the application would ...
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1answer
673 views

Applying Transformation Matrices to VBOs in OpenGL

So I've recently tried to add Vertex Buffer Object Matrix transformation to an OpenGL engine I'm working on. I could go about this by applying the matrix to a copy of each vertex individually, but ...
6
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1answer
745 views

Dual paraboloid shadows on GLSL

I'm trying to port an XNA example to OpenTK + OpenGL, I found it here http://graphicsrunner.blogspot.com.es/2008/07/dual-paraboloid-shadow-maps.html But I'm having a really hard time, I think my maps ...
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1answer
2k views

OpenTK Ray Picking

I just can't get ray picking to work (I need to drop old working faedback mode, and replace it with color pick, but because my scene can have up to 300K+ objects it is reasonable to filter (it's a ...
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0answers
18 views

CanDraw in large hierarchical scene with rotation

I've been assigned to write small simulation visualization, that contains thousands of cubes (I know you heard that before). Now I'm working on optimization of stuff that takes place there, but ...
2
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0answers
984 views

Cannot convert bitmap to texture [closed]

I'm doing a little C# / OpenGL project and I can't manage to load textures properly. So here is my texture class : ...
2
votes
1answer
2k views

OpenGL: Draw an arrow

I'd like to know how to draw an arrow to represent a vector position, length and direction. The issue is that I can't quite find an easy way to know the location and rotation of the triangle ...
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1answer
1k views

OpenGL why point's size stay the same while zooming/unzooming

i'm currently working on a game engine for a college's project. While implementing some debug tools I came across a little problem. When i'm drawing point on the ModelView Matrix the point's thickness ...
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1answer
452 views

Legal Implications of using Openal in Opentk Commercially

Myself and my friend are currently creating a game, which we plan on selling upon its completion. We are using opentk. I read over this: http://www.opentk.com/node/532 , and it pretty well describes ...
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1answer
229 views

OpenGL not rendering full scene, it is a mystery [closed]

I am trying to draw a scene in the sort of style of mock vector graphics. I've helped on a 2D game before with GLSL, but I tried to keep a simple approach to this project since I'm working by myself, ...