Sun issue ?

Started by Vampyrebe, January 22, 2008, 11:06:19 am

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Vampyrebe

Hello all,

I'm busy right now rendering a sunset over the sea... In my first tries, it was all fine... And when I decided to have a huge sun, the reflect in the water was still the same.

Is it an issue when the sun is way bigger than the normal that the reflect on the water is still standard dimension ?

I tweaked my image including some clouds to cover the reflection of the sun, and it makes it way more realistic... Just wondering... ;)

bigben

I think this is a known issue. You can always add a planet at the same angular position as the sun and tweak it to look like the sun (turn cast shadows off) That will at least fix your reflection

Vampyrebe

Ok, thanks for letting me know this... I'll have a try... Or do some postwork in Photoshop

Matt

January 23, 2008, 07:48:30 am #3 Last Edit: January 23, 2008, 07:51:27 am by Matt
Terragen deliberately does not reflect the sun itself, instead it reflects the light from the sun using the specular highlight feature of the water shader or reflective shader. This is done to avoid aliasing difficulties when the sun is small and also to make sure that the light from the sun is not counted twice (specular highlight + reflection of sun object). In future we may be able to add an option to the sun settings to choose which type of reflection it should create (specular highlight or reflected object).

You may be able to get a more realistic result if you increase the "min highlight spread" parameter in the water shader (or specular roughness if you are using the reflection shader).

Matt
Just because milk is white doesn't mean that clouds are made of milk.

Vampyrebe

Many thanks for your answer. Now that the image is rendered, let me show the result :



As you can see, the reflection is very bad against this huge sun.

I tried to increase the min highlight spread but it seems to darken more the ocean (I didn't used the reflection shader, just the standard water). I'm not that far advanced in Terragen to do better for the moment.

I post worked the image to correct some clouds against the sun (clouds are not transparent against the sun), and added a reflection in Photoshop. I'm not a genius in postprocessing, but I tried my best... Hope this kind of image will be possible in Terragen ;) Just love the sunsets...