Render bug with long spikes/hairs

Started by AndyWelder, September 05, 2007, 05:07:40 am

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AndyWelder

I don't really know how to describe this, I'll let the image do the talking.
The only solution I found was to lower the render detail settings but that's not a real solution, isn't it?
Changing displacement settings also worked but hey, hairy critters should look hairy, not like snails! ;)
"Ik rotzooi maar wat aan" Karel Appel

Matt

Generally speaking, the renderer is not good with very spiky displacement like this, and was not designed for it. Improvements will be made in this area, but very long thin spikes are very difficult to render as displacements and I cannot make any promises that there will be a solution to this.

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

Matt

If the extreme spikes are not what you wanted, then it looks there is one very small object at the front which is causing all the problems. It looks like a sphere has been displaced inwards and then has spikes applied. If there is only one fractal which is causing this displacement then you probably need to change the fractal parameters (particularly displacement amplitude, lead-in scale and feature scale).
Just because milk is white doesn't mean that clouds are made of milk.

AndyWelder

Thank you for the swift response, Matt.
The extreme spikes were what I was looking for, I wanted to render some hairy critters  :D
The critters are made of spheres and all three have the same setup, except for the size.

Hope to see a Terragen that will render "hair" someday but I'm aware that hair isn't a common landscape ingredient.  :D
"Ik rotzooi maar wat aan" Karel Appel

Matt

Quote from: AndyWelder on September 05, 2007, 10:07:51 am
Hope to see a Terragen that will render "hair" someday but I'm aware that hair isn't a common landscape ingredient.  :D


Well, grass is important, and that's not much different to hair as far as a renderer is concerned. We just need better tools for covering objects with grass, and I hope we can improve those in future. Unfortunately displacement isn't a reliable way to do it.

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

efflux

I utilized this effect in a render a while back:

http://www.renderosity.com/mod/gallery/media/folder_148/file_1473044.jpg

The trouble is that the renderer cuts off parts of the displacements as in your picture so some patch renders are necessary. However the effect is particularly cool in an app which does GI because the spikes get lit nicely. They look less like artifacts.

Volker Harun

I am doing a render with 500m high, 50m wide spikes every few kilometer.
It seems to be a matter of luck concerning the quality and GI-settings to get the spikes rendered.
Cropped scenes are more likely to be complete.

Volker Harun

October 12, 2007, 03:29:00 am #7 Last Edit: October 12, 2007, 03:35:16 am by Volker Harun
I think it would be a good idea to push this forward to get some Mojo-like results.

It is no matter to use a procedural or a heightfield by shader. The last point bothers me most.

AndyWelder

Groovy shapes, Volker; too bad they didn't render in the big pic.
And it certainly has a Mojo feel!
"Ik rotzooi maar wat aan" Karel Appel