glsl

问题 I wrote a geometry shader to compute the intersection contour of a mesh and a plane, but at the intersection points there are sometimes 1 pixel wide gaps between two lines. The shader first computes the signed distances of the triangle vertices to the plane. It then checks if two distances have a different sign to determine if there is an intersection with an edge. If so, it emits a vertex at the intersection, which is computed as the weighted average between the edge points. #version 330

问题 This may be a bit of a naive question so please go easy on me. But I was looking at shaders at shadertoy.com and I'm amazed at how small the glsl code is for the 3d scenes. Digging deeper I noticed how most of the shaders use a technique called ray marching. This technique makes it possible to avoid using vertices/triangles altogether and just employ the pixel shader and some math to create some pretty complex scenes. So I was wondering why is it that 3d scenes often use triangle meshes with

问题 Details: I have a glsl fragment shader with a uniform texture, "u_MapTexture" with several thousand colors on it (max of about 10k-15k unique rgb values). I also have a uniform palette texture ("u_paletteTexture") that is 16384 × 1 that I want to use to index the colors on u_MapTexture to. My problem is that no matter what I try mathematically, I can't seem to properly index the colors from the first texture to the palette texture using the RGB values of the passed color. Amy thoughts or

问题 I wrote a program that simulates soft bodies using springs. It looks nice but the problem is it consumes a lot of CPU time. So I can not run it on my laptop or any not high end PC. I thought It would be a good idea to write a vertex shader and move the logic to the GPU. I've read some tutorials and made a toon shader so I thought (wrong) I was ready to go. The big problem I have is that I need to know the old position of a vertex to calculate the new one. I don't know how could I retrieve a

问题 I am trying to read shader strings from a file; however, I faced with a problem at glShaderSource() function line. As you know, glShaderSource() takes const char** , and I have to declare char * for reading from the file. So, I am using casting to convert types. If I use const_cast<const char **> , the shape appears; however, it has wrong color (It should be orange not white). If I use reinterpret_cast<const char**> , I get a Access violation reading location 0x73726576 error in running time.

问题 Is it possible to access a rendered image (GLSL) in the next frame with shader toy? 回答1: Now they have implemented rendering to buffers, so you can render to buffer. Actually, you can use up to four buffers, if you need. Also, watch useful demo. 回答2: No. There is no access to previously rendered frames. 来源： https://stackoverflow.com/questions/33634861/getting-rendered-screen-as-feedback-texture-shadtertoy

问题 I am trying to implement atmospheric scatting in GLSL version 4.10. I am adapting the shaders from the this Shadertoy shader https://www.shadertoy.com/view/lslXDr. The atmosphere in my program is created from a scaled version of the planet sphere. I have the actual scattering equations working, but the inner radius of the atmosphere does not line up with the outer radius of the sphere for most camera positions. I know this is from the radius of the atmosphere being bigger than the planet

问题 new to shaders here, and a bit puzzled. I want to specify textures to be used when I render an array of sprites. So I put a texture index in their vertex data, and pass it as a flat value from my vertex shader to my fragment shader, but can't use it to index an array of samplers as expected because compiler sees it as "non-constant". Instead I have to resort to the disgusting code below. Can anyone explain what is going on here? const int numTextures = 2; uniform sampler2D textures

问题 I'm using OpenGL for rendering, and when I write linear values to the default framebuffer (without any gamma correction) they appear linear on my monitor. This goes against everything I thought I knew about gamma correction (as explained here: http://gamedevelopment.tutsplus.com/articles/gamma-correction-and-why-it-matters--gamedev-14466 ). Without gamma correction, I would expect to see mid-range colors darkened non-linearly by my monitor. But here is what I actually see; first with no gamma

问题 I declare my GLSL ES shader program within a HTML file, using this code: <script id="shader-fs" type="x-shader/x-fragment">..shader-code..</script> as seen in the learning WebGL examples. Everything works fine, but I dont understand why I should use the type attribute of the script tag. I want to know where the "x-shader/x-fragment" value is specified. Who does that.. the W3C, the Khronos Group or the browser developers? Can anybody help me? Tahnk you. 回答1: There is no official organization