Questions about how Irrlicht drawing is done.

WindScar · Post by **WindScar** » Fri Sep 03, 2010 9:31 pm

1. First you add nodes to the Scene Manager. Each node contains one or more meshes. Then you add a CameraSceneNode to the scene manager and configure it. Then you call the function drawAll() of your scenemanager objects and everything is drawn to the video buffer based on that CameraSceneNode. Is this all right?

But what if you add 2 CameraSceneNodes? Is there a way to switch between them?

And also about some functions from the video namespace like video::draw3DLine. Will those functions use the CameraSceneNode on the Scane Manager object to calculate the projection? What if there is no Scene Manager created in the program? How to set the camera for the video drawing functions?

Thanks in advance.

hybrid · Post by **hybrid** » Fri Sep 03, 2010 9:39 pm

Most of these things should be answered by the tutorials. Please read them thoroughly.
All functions use the currently set projection matrix, except they do their own projection handling.

WindScar · Post by **WindScar** » Fri Sep 03, 2010 10:25 pm

How do you set the current projection matrix? I swear I've read the whole documentation and didn't find the answer.

vitek · Post by **vitek** » Fri Sep 03, 2010 10:29 pm

IVideoDriver::setTransform() is used to set the transformation matrix that is used to render. The active camera scene node automatically sets the view and projection matrix.

You could find this pretty easily by tracing through the source of ISceneManager::drawAll().

Travis