CODEWITHSUNDEEP
iphoneopengl-estextures
Sivakumar
Sivakumar

Reputation: 11

How to apply a texture image in GLGravity Teapot iphone?

For openGl expample, Xcode given a project GlGravity. But Instead of showing yellow color how to apply a Texture image without textureCoordinates?.

Upvotes: 0

Views: 500

Answers (1)

datenwolf
datenwolf

Reputation: 162164

You need some kind of texture coordinate, otherwise the whole concept of textures makes no sense: A texture is a function mapping a set of n coordinates to some value (depth, luminance, alpha, colour or combination of those) defined by data the samples are taken from and interpolated.

You can generate the texture coordinates, either statically from your mesh, or in the vertex shader. Or you supply them directly. But you need some texture coordinates to make this work. A very cheap and simple texture coordinate generator is using the vertex position as texture coordinate; this will project your texture along the coordinates axes onto the model. So if you've got a 2D texture it will be applied in the XY plane, as if there were a parallel projecting slide projector at coordinates (0,0,\infinity).

Upvotes: 1

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