Thanks for your feedback Tristam. I actually do agree with both of you guys that this is GPU/shader territory.
I am mainly looking at it from the viewpoint of a user thats using Pyglet 1.3, and has little or no OpenGL knowledge. For example, I have a little side-scrolling shoot-em-up game I made to play around with projection and "2.5D" style side scrolling. Lets say I have a single asteroid model that I want to place in the background at various random positions and rotations. Having a few transform methods would let you randomly place them at runtime without needing to create a full scene in an editor. That's basically it. Do you think it would harmful to include transform methods, in the sense that we would be giving users tools that they probably shouldn't really be using anyway? On Tuesday, June 6, 2017 at 11:45:13 PM UTC+9, swiftcoder wrote: > > I'm not sure it's worthwhile to include *at all*. What's the advantage of > doing that, versus transforming the model on the GPU? > > Matrix * vector operations in the vertex shader are really cheap, and most > programs are limited by the fragment shader performance. > > The only case where this might be a win is if you are assembling a level > from singular geometries at runtime. Which seems a vanishingly unlikely > case - generally you would assemble static elements in your editor, and > then add multiple copies of props, etc at runtime. > On Tue, Jun 6, 2017 at 00:29, Benjamin Moran <[email protected] > <javascript:>> wrote: > >> >> >>> ISTM that gross operations on the model (transformations on all vertices >>> like the translation - I think that's what you mean by "shifting the >>> model") should be handled entirely by a shader, and no actual vertex data >>> manipulation, since setting the shader variable will be infinitely faster. >>> >>> >>> Richard >>> >>> Yes, sorry, I do mean translation. And you're absolutely right that it's >> silly to do these types of transformations on the CPU in a realtime >> application. >> I was mainly thinking that it's useful to have transform methods to >> reposition static objects in the scene when you first load them. >> I think the only possibilities are passing arguments to the >> pyglet.model.load function, or doing it right after loading. If you do it >> after loading, the following three methods should cover most bases: >> Model.update(x, y, z) # Translate on a specific axis. >> Model.scale(1.0) # Rescale the entire model. >> Model.rotate(x, y, z) # Rotate along one or more axis. >> >> This would come with a big fat warning about not doing this every frame, >> and of course using shaders is going to be necessary for most things. >> Does that sound reasonable? >> >> -- >> You received this message because you are subscribed to the Google Groups >> "pyglet-users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> Visit this group at https://groups.google.com/group/pyglet-users. >> For more options, visit https://groups.google.com/d/optout. >> > -- You received this message because you are subscribed to the Google Groups "pyglet-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/pyglet-users. For more options, visit https://groups.google.com/d/optout.
