0
votes
1answer
74 views

OpenGL Reconstructing Position from Depth

I know this has been asked a lot of time before but none of those answers fixed my problem. I try to implement deferred shading and to do so I need to reconstruct the world space position from the ...
0
votes
0answers
44 views

OpenGL - How to use depth checking and alpha blending at the same time? [duplicate]

Suppose I have a semi-transparent object (let's call this "bubble"), a solid object (let's call this "wall"), and the bubble is closer to the camera compared to the wall behind it. If I draw the ...
0
votes
2answers
115 views

Accesing depth buffer from shader

I read this presentation and on 6th slide I found that is not need to use multiple render targets and depth can be taken directly from depth buffer. From which version of DirectX or OpenGL can be ...
4
votes
1answer
611 views

using heightmap to simulate 3d in an isometric 2d game

I saw a video of an 2.5d engine that used heightmaps to do zbuffering. Is this hard to do? I have more or less no idea of Opengl(lwjgl) and that stuff. I could imagine, that you compare each pixel ...
5
votes
0answers
125 views

How to pass depth buffer from OGRE to CUDA?

I am using OGRE for rendering some objects. At every frame, I would like to pass the resulting depth buffer to CUDA for running some kernels on it and computing a result. How can I achieve this? How ...
0
votes
0answers
103 views

Depth Test not working properly on Nvidia

So, I send a Development Test of my in-dev game to some friends, and they found out that the Depth Test in OpenGL does not work on Nvidia. I use my own matrices and sent them to the shader, and at ...
5
votes
1answer
422 views

Slow glReadPixels

I have implemented a lense flare for my game, and it looks great. The first draft used individual sprites each with its own draw call. This was very slow, so I reengineered it to use a single draw ...
2
votes
2answers
128 views

How scanline rendering finds an intersection with an object

I'm a newbie with graphics and after I read many articles on the web I still don't understand how in rasterizing from a pixel coordinate like (0;0) on the screen the intersection with an object (let's ...
1
vote
2answers
460 views

How to clear a buffer to 1.0 instead of 0.0 in OpenGL?

Using glClear() you can set the buffer specified by the parameter to 0.0. This is useful say if you want pixels not covered by models to be black. Because vec3(0.0, 0.0, 0.0) results in black. But ...
4
votes
1answer
287 views

How do you display non-cutout transparent 2D textures with a depth buffer? (OpenGL)

I've been able to get my 2D renderer to display transparent cutout textures by testing the alpha of a fragment and discarding if it is less than 1 (or any fraction really). The problem is I want to ...
0
votes
2answers
413 views

GLSL light coloring blocked surfaces

I have created a very simple lighting shader. It currently only supports point lights, but it lights up surfaces that are completely blocked from the light. I know why, but I want to know how I can ...
4
votes
1answer
521 views

Can I use the default depth buffer when drawing to FBO?

How to attach default depth buffer to FBO? How to use depth renderbuffer buffer attached to FBO (after drawing to it) as a default depth buffer? Basically I want to use the same depth buffer for both ...
3
votes
1answer
856 views

Renderbuffer to GLSL shader?

I have a software that performs volume rendering through a raycasting approach. The actual raycasting shader writes the raycasted volume depth into a framebuffer object, through gl_FragDepth, that I ...
4
votes
1answer
617 views

The Depth buffer and Perspective

I'm having trouble understanding the behaviour of my OpenGL program; and in drawing my Z-Buffer out to the screen. It will probably be best to just start with code, here is my GLSL shader: in vec3 ...
3
votes
2answers
2k views

computing gl_FragDepth

I am trying to draw spheres using a billboard, so I have a normal map with a z component that I am sampling in my fragment shader. I just need to add this z component to the depth of my fragment to ...
3
votes
0answers
816 views

Sampling from depth texture causes shader to stop working [closed]

I'm currently having issues with depth textures. When I sample from a depth texture it causes my other samplers to fail. For example, when I set gl_FragColor manually the depth buffer is correct. I ...
2
votes
1answer
441 views

Writing the correct value in the depth buffer when using ray-casting

I am doing a ray-casting in a 3d texture until I hit a correct value. I am doing the ray-casting in a cube and the cube corners are already in world coordinates so I don't have to multiply the ...
9
votes
2answers
5k views

How do I use depth testing and texture transparency together in my 2.5D world?

Note: I've already found an answer (which I will post after this question) - I was just wondering if I was doing it right, or if there is a better way. I'm making a "2.5D" isometric game using OpenGL ...
5
votes
2answers
3k views

In OpenGL Can I Discover the Depth Range of a Depth Buffer?

I am doing a GL multi-pass rendering app for iOS. The first pass renders to a depthbuffer texture. The second pass uses the values in the depth buffer to control the application of a fragment shader. ...