Using renderer.render and composer.render together

Is it possible to call renderer.render to render a scene and then call composer.render to render additional scenes?


renderPass.clear = false;
composer.addPass( renderPass );
composer.addPass( outlinePass );
composer.addPass( fxaaPass );
renderer.render(gridScene, camera);

The outline pass seems to throw away the previous render.
The reason I want to do this is so I can avoid running fxaa and gamma correction on some of the scenes.

Well, basically it is possible but only if the pass renders “on top” on the existing framebuffer data (so it does not perform a clear). If you need this behavior for OutlinePass, you have to change the implementations according to your needs.