DEM and Water bodies

[petergrealy]

Hi,

Has anyone had issues with DEM imports not showing the correct water line edges of coastlines? I'm rendering a coastal scene in Australia and I've imported DEM data but whenever I add a water body/lake the water bodies are in completely the wrong areas, like the DEM model has been tilted. Whats weird is that when I export the hightfield terrain from T2 into a 3d app all the water edges/coastline edges are correct. Any advice would be great.
Example of my problem attached.

Cheers, Peter
[attach=#]

[Henry Blewer]

I have noticed this when I make a surface layer and constrain the altitude. When I add a Lake, and enter the same altitude the lake appears well below the constraint altitude of the shader. Checking the use y for altitude does not seem to make any difference.

Peter, welcome to the forum!

[Oshyan]

This is probably something to do with the interaction between heightfield, flattening, planetary curvature, and lake water level conforming to planet (or not). This becomes a potential issue at larger scales. First, try turning off "Flatten Surface First" in under the Displacement tab in the Heightfield Shader. Alternatively, you could try unbinding the Lake object from the planet surface and it should stop conforming to the curvature of the planet. I'm not at my TG computer so I can't verify these things at the moment, but I do think the solution is somewhere in these options. Another possibility to consider, if you do want planet curvature on your heightfield, is use of a 2nd planet completely covered in water and slightly larger than your primary planet, such that it gives you the right water level. It can be more difficult to control this way, but it does allow better full-planet watever and continent coverage.

- Oshyan

[petergrealy]

Thanks for being so welcoming guys , nice to be here.

Unchecking "flatten surface first" in the heightfield displacement dialog seemed to do the trick. My next dilemma was how to add infinite ocean in the back ground but Oshayan you already have anticipated and answered this already.

Thanks heaps guys

[Henry Blewer]

I'll give it a try Oshyan, thanks. It seems to become more extreme when I get farther away from the 0,0,0 coordinates of the heightfield.
I often generate very large heightfields. I do not think these conform to the planet surface. Is this correct?

Peter, I think you'll find everyone here quite helpful. The staff at Planetside regularly read the forum posts, and offer their knowledge. They have been wonderfully helpful.

[Oshyan]

If "Flatten Surface" is unchecked the heightfield will curve with the planet. Coordinate issues can still occur far from the 0,0 origin though.

- Oshyan