Ground Plane horizon is too sharp when blended to horizon

Rendering
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1

Hi everyone,

I’m rendering a boat and I want the Ground Plane (water) to fade out smoothly into the HDRI environment horizon.

I have applied a radial transparency texture to the transparency map, as you can see in the image below, but I can’t get it to work. My goal is to find a more efficient way to blur that solid horizon line, which currently looks very sharp and unrealistic.

Do you know of a better way to make the horizon line look softer and less marked?

Thanks!

Rhino render
Rhino render1226×306 237 KB

Rhino render 3
Rhino render 3530×822 37 KB

Rhino render 2
Rhino render 21223×279 186 KB

2

Hi @Borja2 ,

You’re on the right track. The problem is the ground plane object is a weird one. It is infinite so the UVs for the blurred texture to create the alpha fade won’t work. Check out this example instead using a large plane. The noise texture uses WCS for the Bump but the Alpha uses the the default Surface UVs. You can scale the plane itself to adjust the effect or make a new blur image for the alpha. You could additionally use focal blur/depth of field.

image
image1920×1083 292 KB

image
image1920×1074 277 KB

FadeAwayHorizon_bj.3dm (212.2 KB)

Currently you may need to set the RhinoCycles.BumpStrengthFactor to .01 in Options > Advanced to get my results.

I hope that helps.

3

FWIW in Raytraced / Rhino Render the ground plane is not infinitely large. Each side of the plane is 2*1.0e+6 units long ( RhinoCycles/Database/ChangeDatabase.cs at 31b7dfc6730fb10862de5bf67f5f1958e04ceaff · mcneel/RhinoCycles · GitHub ), the ground plane is always centered at w0,0,0. The plane is divided in 100x100 faces.

Anyway, you an look further at the code linked to see how things are set up for Raytraced and Rhino Render.

4

Hi!

Thank you so much for the help and the example file. It worked perfectly! Using a large plane instead of the Ground Plane allowed me to correctly map the radial transparency and finally get that smooth transition into the HDRI horizon.

The tip about using WCS for the Bump and Surface UVs for the Alpha was exactly what I needed.

Best regards!

5

2,000,000 units LOL… not infinite true but for all intents it might as well be. The texture mapping control is also unique for the GP making this use case impossible as far as I see.

6

If modelling in millimetres, that’s less than half way to the horizon for an adult standing at sea level and looking out to sea. Long way from infinite…

7

I suppose it’s just as far from infinite as anything else :winking_face_with_tongue: