Lake Object Artifacts

[WAS]

One of the reasons I never use the lake object in Terragen is this



It appears in a lot of images with any large amount of reflection. You can see the vectoring of the lake object disc.

But in a current scene I'm working on I need lakes higher then my global ocean. But one of the shots pans the reflections of the lake where these artifacts will be visible.

How can I go about hiding them?

[bobbystahr]

One of the reasons I never use the lake object in Terragen is this



It appears in a lot of images with any large amount of reflection. You can see the vectoring of the lake object disc.

But in a current scene I'm working on I need lakes higher then my global ocean. But one of the shots pans the reflections of the lake where these artifacts will be visible.

How can I go about hiding them?

I have been using a displaceable cube scaled huge in the X,Z and tiny(.2) in the Y for my water lately... The nice thing is it's rotatable and scalable so I can fit it a lot of places I had problems with the Lake object.

[Tangled-Universe]

Either replace the object with a plane object or move the camera away from the origin (it is now, by the looks of it) or move the lake object away from the center.
As far as I know this can't be overcome.

[bobbystahr]

So, here's the .tgd and evidence that the artifacts are non existant on my cube technique. An added benefit is you can raise and lower the water height by scaling the Y axis. In this instance I left it at 1 metre.

[dandelO]

GI Blur Radius is separate from the antialiasing filters. Some of the filters *are* very soft (or sharp).

Render Detail Jittering and Microvertex Jittering are both intended to improve the quality of renders, particularly in certain situations, by introducing a bit more "randomness" and thus reducing the "computery" look, in a sense. Microvertex Jittering in particular addresses the "parallel lines" sometimes seen in water and surface layers. I believe Detail Jittering may be more useful in animations, though I'm not sure. Matt may elaborate here.

Both do result in longer render times I believe, but should not be hugely significant.

- Oshyan

[Tangled-Universe]

It crossed my mind to mention microvertex jittering (MVJ), but since the settings are hidden since v3.3 I thought I'd better not confuse the discussion by mentioning it.

However, it doesn't matter much, as it does not have to do with MVJ in this case. I have seen this too, with MVJ enabled.

[WAS]

Thanks for the information guys, and thank you Bobbystahr for the alternate idea, which works out rather well and easy to move about and scale.

Also I tried moving away from the source to no avail. If you are by one of those lines, it will show when you are close to the surface and there are reflections.

[bobbystahr]

The only problem really with the cube is it doesn't follow the terrain...I think the lake does but have never done a render where that was a consideration

[dandelO]

Ah-hah, seems I'm behind the times!

I'd use a plane myself or, a planet-scaled/transformed sphere with a displacement offset value to control water level.

[bobbystahr]

Ah-hah, seems I'm behind the times!

I'd use a plane myself or, a planet-scaled/transformed sphere with a displacement offset value to control water level.

Yeah that's a good one I guess, but the cube is infinitely more flexible orientation wise than that clunky old plane...sorry I just hate it. The sphere/planet option with masking is also a good one.

[WAS]

Ah-hah, seems I'm behind the times!

I'd use a plane myself or, a planet-scaled/transformed sphere with a displacement offset value to control water level.

Yeah that's a good one I guess, but the cube is infinitely more flexible orientation wise than that clunky old plane...sorry I just hate it. The sphere/planet option with masking is also a good one.

I must have scrolled passed that part by DandelO. I usually use a sphere (there is one in this project) but I needed some higher altitude lakes.

[dandelO]

No worries. Microvertex Jittering seems to be an unpoint here anyway then.

And I must say that I've also, indeed, seen these type of lines in a regular Surface Layer on the Planet object, when I was running lots of fake grass shader tests a long time ago, and with MVJ enabled.
Generally, it will help on a regular Lake object but I always prefer to use planetary Spheres, with offset and masking for water.