Post-processing effects

[Admin]

Technology in Leadwerks passes through two stages. First, it becomes possible through code. Then, it is documented and a front-end in the editor is build so it can be easily controllable with a visual interface. Post-processing effects are now possible with Leadwerks 3, but are still in the first stage of maturity. They will remain undocumented until we are sure how the front-end will work, and we document and lock down the post-processing API.

 

To add a post-processing effect, just call Camera::AddPostEffect(Shader* shader), passing in the loaded shader for your effect. I provided one shader for bloom, found in "Shaders/PostProcess/bloom.shader".

 

The following textures are provided:

• texture0: color
  
• texture1: depth
  
• texture2: blurred color (for DOF, bloom, etc.)
  

 

The engine is smart enough that it will only perform the blurred downsampling if a shader is present that uses that texture slot.

 

The renderer will pass the effects back and forth between two buffers after rendering, so that the output of one pass will be used for the input of the next pass. This lets you combine multiple post-processing effects in a sequence. Post-processing effects will be executed in the order they are attached to the camera.

 

You can call Camera::ClearPostEffects() to remove all post-processing effects.

 

Post-processing effects work on all platforms, but may run slowly on some mobile devices.

[karmacomposer]

How would I do this in Lua?

 

Can you assign more than one shader to a camera? For example, I want Bloom, DOF and Water Droplets - is this possible?

 

Where can we get other shaders that would work with Leadwerks 3?

 

Great update, by the way!

 

Now for terrain and water!!!

 

Mike

[Admin]

The Lua API is the same as C++. You can assign multiple post-processing effects. At this time, we provide a shader for bloom.

[Guest Red Ocktober]

can you comment on what kind of performance hit can be expected for stuff like fog or bloom...

 

--Mike

[gamecreator]

As mentioned elsewhere, please try to implement control over how powerful a shader is, if possible. I don't know what the function would look like but I'm thinking something like SetBloom(0.5f) to activate bloom at half strength, SetBloom(2.0f) for double strength, etc. It would be great to have control over at least the strength of the effect.

[shadmar]

camera->AddPostEffect();

seems to destroy my buffers or something wierd is happening or overwrite all texture bindings putting it's own screen texture into all of them.

I also tried to change the texture bindings to something other than textures0,1,2 but didn't seem to resolve my problem.

[Admin]

You don't need to use your own buffers with the post effects. The camera will automatically set up what it needs.

[shadmar]

Yes but I do have som buffers for reflection which won't work when postprosessing is added.

[Admin]

I don't know exactly what you're doing, but you might need to use texture slots that aren't being used as described above.

[shadmar]

I will send you an example.