Cloud Issues

Started by rmfrase, February 22, 2007, 08:36:13 PM

Previous topic - Next topic

rmfrase


I haven't noticed this before except on my images.  I've attached (2) images. And the .TDG.   One image is the Render (90% Clouds test 5) the other is an upclose detail shot (detail) of the issue I'm having.  The cloud images have white specks all over it. :(

Any suggestions/corrections? 

For the ocean, although I understand that it is still under development, I'm looking for more of the Sloping (spelling?) high crests, and low troughs.  Although the image here has waves, it doesn't have the Ocean type waves I'm really looking for.  ie: straight-line (see example from Istock)



Thanks in advance for your help.   

Will

whats your cloud sample setting at?

and whats your atmopsphere setting at.

Regards,

Will
The world is round... so you have to use spherical projection.

old_blaggard

I think it's an atmosphere setting thing.  For a scene with this amount of rays and shadows, you'll probably need at least 64, maybe 96, or maybe even 128 samples.
http://www.terragen.org - A great Terragen resource with models, contests, galleries, and forums.

rmfrase


Will

for atmosphere? That seems really high are you sure thats not the cloud samples?

Regards,

Will
The world is round... so you have to use spherical projection.

rmfrase

Atmosphere Sample was at 16.  I'll adjust according to the suggestions made.

Thanks.

Oshyan

The white specks are light samples shining through the clouds. This is an accuracy issue as others have suggested. 16 samples is definitely too low for a complex lighting situation like this. I would think 64 should handle it better, although 128 may be necessary. Given the presence of reflective water you should unfortunately prepare for a long render when you increase the atmosphere samples.

As far as wave shape goes, keep in mind you can plug any shader into the Water Shader input to create shape. Rolling waves aren't really going to be realistically possible, but most other normal wave shapes will be.

- Oshyan

rmfrase

Oshyan,   

I apologize, but I'm apparently missing something in translation from what you stated.  "keep in mind you can plug any shader into the Water Shader input to create shape."   
Could you be so kind, (or any of the readers out ther) when you/they have a moment to elaborate on this?  Maybe an example or settings?

Sincerely,
Robert

Will

basicaly he is stating that you can connect and shader's output into the water shaders input.


regards,

Will
The world is round... so you have to use spherical projection.

rmfrase


Is there a tutorial that is available that I can read up on this method?

Will

don't know of one but check around the fourms and this link has good tutrials for you: http://www.designpaths.com/terragen-tutorials/

regards,

Will
The world is round... so you have to use spherical projection.

Oshyan

To give you an example to further explain what I said, let's say you create a basic Lake object. In the Node Network View you will see a Water Shader 01 connected to its input. On the top of the Water Shader is another input. Right-click in the network, go to Create Shader->Surface Shader->Power fractal shader v3. Now connect the output of this shader to the input port on the top of the Water Shader. You should see your water surface turn partially white - the Power Fractal is now providing color as well as displacement, although the displacement is very small right now. Next open the settings of the Power Fractal (double-click the node in the node network). On the Scale tab change Feature Scale to around 1000 and Lead-in scale to around 10,000. On the Color tab uncheck Apply High Color (unless you want to color your water - for now we should have it off though). On the Displacement tab set Displacement Amplitude to around 500. You should now see really big waves! Because you're using a lake object you may also see the terrain underneath showing through where the water level dips down below the planet surface, but this could be fixed by either using  Water Shader on the planet itself, or by simply raising the lake level, or adjusting amplitude, etc.

The important thing is the fundamental principle: you can plug any shader into the Water Shader input and it can affect the water. If you put a Default Shader on there you can easily change the water's color, for example. Any shader that provides displacement - a Power Fractal, Default Shader (with an input in its Dispalcement port), or a Displacement Shader can all do this, as can a Heightfield Shader. Yes, in fact you can create water shape with heightfields, so you could even go into a paint program, paint your water shape, and then use that on your water in TG2, possibly combining it with a smaller-scale built-in fractal for smaller-scale detail and greater realism. The possibilities are almost endless.

I recommend you simply experiment with the basic shaders available in the Shading and Terrain layouts and using those nodes connected to the Water Shader to see how well they work. Basically anything that can create terrain can also effect water shape. Water is essentially just another surface type in TG2...

Let me know if you need further explanation of any particular point.

- Oshyan