Tests of speed when using textures

All objects in VRML can has a texture on their surface. The texture replaces the diffuse term of the material. When computing a color of the pixel on the surface, all the terms of the material characteristics are used except the diffuse term. It is taken from the texture. This is how it should be, but a lot of browsers behaves differently. Some of them for example ignore the transparency and specular highlights on the texture mapped objects. While mapping a texture on the surface an alias occures. It can be partially eliminated by using the bilinear filtering, which is quite costy. Some of the browsers performs it, some don't. When comparing the speed of texturing, it is important to assure that the quality of the texturing is the same in all compared browsers.

In this test we will compare the rendering speed with and without texturing. We will use textures of different sizes and also a different number of textures with the same size. The test is divided into two parts. In the first one, we apply the texture to one object (10000 triangles). The thing which varies is the size of the texture. First we use the object without a texture, then with a texture 1x1 pixel, then 512x512, 2048x2048 and 4096x4096 pixels. CAUTION!!! The size of raw image data for the texture 4096x4096 if 50MB and therefore, if you don't have at least 64MB of RAM in your computer, you'd better skip this scene.

In the second part, you will find, how does your browser manage a large number of textures. The scene is again the same during the test. It consists of a matrix of 32x32 octagons, this is 1024 objects (8192 triangles). In the first scene, there are no textures. In the second one, we use the same texture for all the objects. The texture is repeated using te DEF/USE construct. In the next two scenes we use 512 and 1024 object respectively. In the last scene, there is again the same texture on all the 1024 objects, but it is not repeated using DEF/USE. The frame rate of this scene should be the same either as in the scene with one texture or as in the scene with 1024 textures. The first case means, that the browser is "intelligent" and knows that we use only one texture and uses it only once. In the second case the browser copied the same texture in 1024 copies and for texturing of each object it uses the data from different part of memory, even if they are all the same. CAUTION!!!The size of one texture is 128x128 pixels. For 1024 textures it is again 50MB of raw image data.

• Tests with varying size of textures
  • Object without any texture
  • Object with textures 1x1 pixel
  • Object with textures 512x512 pixels
  • Object with textures 2048x2048 pixels
  • Object with textures 4096x4096 pixels
• Tests with varying number of textures
  • 1024 objects without textures
  • 1024 objects, one texture
  • 1024 objects, 512 textures
  • 1024 objects, 1024 textures
  • 1024 objects, one texture (no DEF/USE)