On Sat, Dec 4, 2010 at 4:05 PM, Ian Mallett <[email protected]> wrote:
> > On Sat, Dec 4, 2010 at 1:21 PM, Christopher Night > <[email protected]>wrote: > >> Hi, I'm working on a standalone OBJ loader based on the well-known one on >> the pygame wiki: >> http://www.pygame.org/wiki/OBJFileLoader >> >> My goal is to speed up load times by making the model objects picklable, >> so the OBJ file doesn't have to be read every time you start up. Here's my >> current version: >> http://christophernight.net/stuff/fasterobj-0.tgz >> >> It still needs some cleaning up, but it's got almost all the functionality >> I wanted. In addition to making things picklable, it has a small >> optimization by combining triangles and quads when possible to reduce the >> number of GL calls. >> >> There are three classes: OBJ (using fixed function), OBJ_array (using >> vertex arrays), and OBJ_vbo (using vertex buffer objects). Additionally, any >> of these can be used with or without a display list. Here's the results of >> my test on some model I had lying around: >> >> type list? parse save load render >> 1. fixed False 146 13 14 0.03fps >> 2. fixed True 124 10 950 117.80fps >> 3. array False 179 8 9 1.26fps >> 4. array True 174 7 30 121.08fps >> 5. vbo False 143 7 8 16.06fps >> 6. vbo True 142 8 12 112.98fps >> >> #2 is the method in the original OBJ loader. The times listed under parse, >> save, and load are times in milliseconds to read from the OBJ file and do >> some preprocessing, pickle to a file, and unpickle from a file. The load >> step also includes generating the display list, if necessary. >> > > I completely would have expected the results in 1-4. > > However, I'm quite surprised at the vbo method 5. It should run in speed > between 2 and 4. I also would have expected 4 and 6 to be much closer. > > How many VBOs are you using? If you switch buffer bindings a lot for each > draw (like your object has 10 different parts, each with a vertex, normal, > and texcoord VBO) then you *might* get results like that . . . > Awesome, thanks so much for taking a look! I'm using 3 VBOs, one each for vertex, normal, and texcoord. This is the entire rendering code for OBJ_vbo: glEnable(GL_TEXTURE_2D) glFrontFace(GL_CCW) self.vbo_v.bind() glVertexPointerf(self.vbo_v) self.vbo_n.bind() glNormalPointerf(self.vbo_n) self.vbo_t.bind() glTexCoordPointerf(self.vbo_t) glEnableClientState(GL_VERTEX_ARRAY) texon, normon = None, None for material, mindices in self.indices: self.mtl.bind(material) for nvs, dotex, donorm, ioffset, isize in mindices: if donorm != normon: normon = donorm (glEnableClientState if donorm else glDisableClientState)(GL_NORMAL_ARRAY) if dotex != texon: texon = dotex (glEnableClientState if dotex else glDisableClientState)(GL_TEXTURE_COORD_ARRAY) shape = [GL_TRIANGLES, GL_QUADS, GL_POLYGON][nvs-3] glDrawArrays(shape, ioffset, isize) glDisable(GL_TEXTURE_2D) For this model, glEnableClientState gets called once for vertices, normals, and texcoords. There are 5 materials, each with one glBindTexture and two glDrawArrays (one for triangles, one for quads). So the total calls per render is: 2 x glEnable/glDisable 1 x glFrontFace 3 x vbo.bind 3 x glEnableClientState 10 x glDrawArrays 5 x glBindTexture 4 x glColor And I'm rendering 40 sprites, so I'm doing this 40 times per frame. I'm assuming that in a real application, each model would have its own separate VBOs. Is that what I'm doing wrong? Or is there something else? The reason it takes so long to load on 2 is generating the display list. This method was taken from the objloader on the wiki, and it involves 1646 glVertex3f calls, one for each vertex in the model, and similarly with glNormal and glTexCoords. Thanks again! -Christopher
