I'm trying to render two different scenes and cameras on top of each other, like a HUD. Both render correctly when alone. Also this works as intended, so you can see mainscene under the helpscene:
renderer.render(mainscene, maincamera);
renderer.render(helpscene, helpcamera);
When I'm using EffectComposer to render the main scene, I can not see helpscene at all, I only see the results of composer rendering:
renderTargetParameters = { minFilter: THREE.LinearFilter, magFilter: THREE.LinearFilter, format: THREE.RGBAFormat, stencilBuffer: false };
renderTarget = new THREE.WebGLRenderTarget( width, height, renderTargetParameters );
composer = new THREE.EffectComposer(renderer, renderTarget);
---- cut out for brevity ---
composer.render(delta);
renderer.render(helpscene, helpcamera); // has no effect whatsoever on the screen, why?
What is happening here? Again if I comment either render call out, they work correctly. But both enabled, I only see the composer scene/rendering. I would expect the helpscene to overlay (or at least overwrite) whatever is rendered before that.
I have quite complex code before renderer.render(helpscene, helpcamera);, it might take various different render paths and use effectcomposer or not based on different settings. But I want the helpscene to always take the simple route with no effects or anything, that's why I'm using a separate render call and not incorporating it as an effectcomposer pass.
EDIT: Turns out it is because some funny business with depth buffers (?). If I set material.depthTest = false to everything in the helper scene, it will show kind of correctly. It looks like the depth is set to zero or very low by some composer pass or by the composer itself, and rather unexpectedly, it will have the effect of hiding anything rendered with subsequent render calls.
Because I'm only using LineMaterial in the helper scene it will do for now, but I expect some problems further down the road with the depthTest = false workaround (might have some real shaded objects there later, which would need depth test against other objects inside the same helper scene).
So I guess the REAL QUESTION IS: how do I reset the depth buffers (or something) after EffectComposer, so that further render calls are not affected by it? I can also do the helper scene rendering as the last composer pass, does not make much difference.
I should maybe mention that one of my composer setups main RenderPass renders as a texture to a distorted plane geometry near a perspective camera created for that purpose (like the ortographic camera & quad setup found in many postprocessing examples, but with distortion). Other setup has a "normal" RenderPass with the actual scene camera, where I would expect the depth information to be such that I should see the helper scene anyway (that's probably some seriously f****ed up english, sorry, non-native speaker here and I could not come up with better words). I am having the same problem with both alternatives.
