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Groups > comp.lang.basic.visual.misc > #3714
| Newsgroups | comp.lang.basic.visual.misc |
|---|---|
| Date | 2024-01-05 18:03 -0800 |
| Message-ID | <589abe90-0885-4e89-80a5-47586acc387fn@googlegroups.com> (permalink) |
| Subject | Pop Art Textures Free Download |
| From | Velma Wiste <velmawiste@gmail.com> |
Hello - is this screen shot from the computer where the textures are added or some other machine? If this is on another machine that does not have the textures, then on the original machine, when you save the file, make sure that saving textures is set - it should be, that is default bahavior - you can see if you use SaveAs: pop art textures free download Download https://t.co/yFqTcH6nar I know this problem from V4 times when i baked textures and updated them, the old images where shown even when overwritten. The only way i remeber to get around it is to rename the texture and reassign it.I think this is maybe a bug. btw. i never change anything in the cache folder, just cleaning it up from time to time if the content got too big. Hi Juan, thats strange. If i rename and reassign, it updates immediately the viewport without using _RefreshAllTextures. On my side VRay renders the file which is on disk when i overwrite the last one, i do not think it uses the cache folder rhino uses. Maybe matt_newberg can sheed some light here, if VRay uses a cache for textures at all? What artists and programmers generally prefer is to use a texture. A texture is a 2D image (even 1D and 3D textures exist) used to add detail to an object; think of a texture as a piece of paper with a nice brick image (for example) on it neatly folded over your 3D house so it looks like your house has a stone exterior. Because we can insert a lot of detail in a single image, we can give the illusion the object is extremely detailed without having to specify extra vertices. The first argument specifies the texture target; we're working with 2D textures so the texture target is GL_TEXTURE_2D. The second argument requires us to tell what option we want to set and for which texture axis; we want to configure it for both the S and T axis. The last argument requires us to pass in the texture wrapping mode we'd like and in this case OpenGL will set its texture wrapping option on the currently active texture with GL_MIRRORED_REPEAT. Texture filtering can be set for magnifying and minifying operations (when scaling up or downwards) so you could for example use nearest neighbor filtering when textures are scaled downwards and linear filtering for upscaled textures. We thus have to specify the filtering method for both options via glTexParameter*. The code should look similar to setting the wrapping method: Imagine we had a large room with thousands of objects, each with an attached texture. There will be objects far away that have the same high resolution texture attached as the objects close to the viewer. Since the objects are far away and probably only produce a few fragments, OpenGL has difficulties retrieving the right color value for its fragment from the high resolution texture, since it has to pick a texture color for a fragment that spans a large part of the texture. This will produce visible artifacts on small objects, not to mention the waste of memory bandwidth using high resolution textures on small objects. Creating a collection of mipmapped textures for each texture image is cumbersome to do manually, but luckily OpenGL is able to do all the work for us with a single call to glGenerateMipmap after we've created a texture. A common mistake is to set one of the mipmap filtering options as the magnification filter. This doesn't have any effect since mipmaps are primarily used for when textures get downscaled: texture magnification doesn't use mipmaps and giving it a mipmap filtering option will generate an OpenGL GL_INVALID_ENUM error code. The first thing we need to do to actually use textures is to load them into our application. Texture images can be stored in dozens of file formats, each with their own structure and ordering of data, so how do we get those images in our application? One solution would be to choose a file format we'd like to use, say .PNG and write our own image loader to convert the image format into a large array of bytes. While it's not very hard to write your own image loader, it's still cumbersome and what if you want to support more file formats? You'd then have to write an image loader for each format you want to support. The function first takes as input the location of an image file. It then expects you to give three ints as its second, third and fourth argument that stb_image.h will fill with the resulting image's width, height and number of color channels. We need the image's width and height for generating textures later on. The glGenTextures function first takes as input how many textures we want to generate and stores them in a unsigned int array given as its second argument (in our case just a single unsigned int). Just like other objects we need to bind it so any subsequent texture commands will configure the currently bound texture: This is a large function with quite a few parameters so we'll walk through them step-by-step: The first argument specifies the texture target; setting this to GL_TEXTURE_2D means this operation will generate a texture on the currently bound texture object at the same target (so any textures bound to targets GL_TEXTURE_1D or GL_TEXTURE_3D will not be affected). The second argument specifies the mipmap level for which we want to create a texture for if you want to set each mipmap level manually, but we'll leave it at the base level which is 0. The third argument tells OpenGL in what kind of format we want to store the texture. Our image has only RGB values so we'll store the texture with RGB values as well. The 4th and 5th argument sets the width and height of the resulting texture. We stored those earlier when loading the image so we'll use the corresponding variables. The next argument should always be 0 (some legacy stuff). The 7th and 8th argument specify the format and datatype of the source image. We loaded the image with RGB values and stored them as chars (bytes) so we'll pass in the corresponding values. The last argument is the actual image data. You probably wondered why the sampler2D variable is a uniform if we didn't even assign it some value with glUniform. Using glUniform1i we can actually assign a location value to the texture sampler so we can set multiple textures at once in a fragment shader. This location of a texture is more commonly known as a texture unit. The default texture unit for a texture is 0 which is the default active texture unit so we didn't need to assign a location in the previous section; note that not all graphics drivers assign a default texture unit so the previous section may not have rendered for you. The main purpose of texture units is to allow us to use more than 1 texture in our shaders. By assigning texture units to the samplers, we can bind to multiple textures at once as long as we activate the corresponding texture unit first. Just like glBindTexture we can activate texture units using glActiveTexture passing in the texture unit we'd like to use: The final output color is now the combination of two texture lookups. GLSL's built-in mix function takes two values as input and linearly interpolates between them based on its third argument. If the third value is 0.0 it returns the first input; if it's 1.0 it returns the second input value. A value of 0.2 will return 80% of the first input color and 20% of the second input color, resulting in a mixture of both our textures. To get more comfortable with textures it is advised to work through these exercises before continuing. Make sure only the happy face looks in the other/reverse direction by changing the fragment shader: solution. Experiment with the different texture wrapping methods by specifying texture coordinates in the range 0.0f to 2.0f instead of 0.0f to 1.0f. See if you can display 4 smiley faces on a single container image clamped at its edge: solution, result. See if you can experiment with other wrapping methods as well.Try to display only the center pixels of the texture image on the rectangle in such a way that the individual pixels are getting visible by changing the texture coordinates. Try to set the texture filtering method to GL_NEAREST to see the pixels more clearly: solution. Use a uniform variable as the mix function's third parameter to vary the amount the two textures are visible. Use the up and down arrow keys to change how much the container or the smiley face is visible: solution. The first thing to do is add code to load the textures. In our case, we'll be using a single texture, mapped onto all six sides of our rotating cube, but the same technique can be used for any number of textures. Note: It's important to note that the loading of textures follows cross-domain rules; that is, you can only load textures from sites for which your content has CORS approval. See Cross-domain textures below for details. WebGL1 can only use non power of 2 textures with filtering set to NEAREST or LINEAR and it can not generate a mipmap for them. Their wrapping mode must also be set to CLAMP_TO_EDGE. On the other hand if the texture is a power of 2 in both dimensions then WebGL can do higher quality filtering, it can use mipmap, and it can set the wrapping mode to REPEAT or MIRRORED_REPEAT. Mipmapping and UV repeating can be disabled with texParameteri(). This will allow non-power-of-two (NPOT) textures at the expense of mipmapping, UV wrapping, UV tiling, and your control over how the device will handle your texture. Again, with these parameters, compatible WebGL devices will automatically accept any resolution for that texture (up to their maximum dimensions). Without performing the above configuration, WebGL requires all samples of NPOT textures to fail by returning transparent black: rgba(0,0,0,0). The textureCoordinates array defines the texture coordinates corresponding to each vertex of each face. Note that the texture coordinates range from 0.0 to 1.0; the dimensions of textures are normalized to a range of 0.0 to 1.0 regardless of their actual size, for the purpose of texture mapping. 35fe9a5643
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Pop Art Textures Free Download Velma Wiste <velmawiste@gmail.com> - 2024-01-05 18:03 -0800
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