smooth out displ for quicker render?

[Dune]

Maybe someone knows, before I start testing. I am making dirt, which has tiny detail, as well as larger clumps and a reflective shader. Would it be better to smooth out small detail in the distance (with an extra series of distance shaders) for faster and less memory consuming rendering? Or would the extra nodes/calculations annihilate the effect of a smoother distance (where small detail will not be seen anyway)?

[FrankB]

That's a good question. I was always wondering about the exact same thing, but never bothered to actually test it.
My guess would be that there's not so much of a difference, except if you have reflective material extend to the horizon. If you don't have ray traced reflections, I would think TG2's LOD optimizations would handle most of it for you. But then, I'm just guessing.

Regards,
Frank

[Henry Blewer]

I think that reducing the reflective shaders coverage would be enough. When I have used it, the render time increases so much that I don't use it. The water shader may be the only exception. Even using a water shader/lake, I try to limit the size.

[Dune]

Thanks guys, as soon as I have some time I will set up a small test to figure this out once and for all.

[domdib]

I'd be interested in the result, as I was just thinking of making a rock texture with a reflective shader.

[Dune]

Here's the result after some quick testing. Interestingly, the distance shader smoothing of distant fine detail took (slightly) longer! More nodes to compute. So no need to elaborate on smoothing out unseen detail in the distance, I guess.

[domdib]

Thanks for that. Nice looking dirt - I guess the reflection is quite subtle - I wonder if a higher reflectivity/index of refraction would produce different results?

[Dune]

Indeed, the reflection is only in the scattered stones (the bluish things).

[Floating.Point]

I would love to get a clip of your mud / clay...
its just what I need for my current scene
Any chance you might share?

[Hetzen]

Interesting experiment Ulco. I think that it's a toss up between 10m and 5m surface shader blends. Less to flicker if you move the camera, and still keep your foreground detail.

[Dune]

@Hetzen: I didn't even think about animation, but this might indeed be interesting to cancel out distant flicker. For me it was to test whether smoothing out the distance reduced rendertime. And it doesn't.

@FP: Here you go: wet+dry mud. A good start anyway.

[Tangled-Universe]

These findings do not really surprise me, since there's a LOD-function in the renderer already.
So what you created with the distance-masking actually already happens within the renderer.

The main cause for flickering is that the LOD differs in between frames and that needs to be blended, hence the detail blending function in the render-options.
But yes, if you mask out detail in the distance then there's less LOD to perform and there's likely less flicker.
I remember the ACM-article which formed the basis of TG2's structure. It clearly mentioned that this blending is simple and effective.
As far as I'm concerned it is very slow and rather ineffective in conjunction with TG2's main strength: multi scale fractal detail