Fake stones shader issue

[Franco-Jo]

I'm new to Terragen so please bear with me. I've just done the Ben McDuff tutorial (http://forums.planetside.co.uk/index.php?topic=7733.0) and I'm having some issues with the fake stones shader which is creating some strange formations, see image below.

http://stot.org/other%20images/stone_issue.jpg

I have altered the tutorial in colour alone really, but otherwise followed it. I've disabled the Fake stones layer to ensure that this was creating the problem and it is. I've also double checked the settings in the tutorial with my own and I've followed them correctly.

Does anyone have any ideas as to what is going on here?

[inkydigit]

hi there, welcome to the forum!
you have 'exploding' fake stones
check here, it may help!
http://forums.planetside.co.uk/index.php?topic=7386.0
cheers

[Franco-Jo]

Thanks very much, inkydigit!

I've tried all of the suggestions in the thread with no luck. I even turn the 'blend as stone density' back on on the off-chance it was happier but no.  I've also deleted the shader and added a new one, followed the tutorial again and it produced the same results. At least I know what they're called now, exploding rocks!

[inkydigit]

do you have any power fractals with displacement enabled as surface shaders for the fake stones?
the smallest scale and displacement values maybe too extreme?(too small/too big)
have you tried a different seed for the fake stones, you can change this by manually typing in a new one.
this may help also...
cheers

[Dune]

It may also occur if you blend your stones by a very sharp PF. At the edge of black and white of this 'mask' a stone might want to appear, but is half hampered, kind of. That's my idea anyway.

[pclavett]

Hi Franco-Jo !

Got the same all the time till I learned to set the distribution parameters less sharp.....ie when you set a height or slope, give it a generous fuzzy zone and you will not get them as much. If you use powerfractals for distribution, less contrast and less roughness should make these things much less obvious as Dune said. Sometimes I wish we had a "blurring" node for some things but apparently this cannot work in this TG2 node world !

Good Luck and take care !

Paul

[billhd]

Try this...make sure you don't have a power fractal with any scale setting less than 0.008.  I get odd sky rendering artifacts with settings small than that and though I have not seen exploding stones in a while the setting may cause the explosions also. 

If the problem persists try regenerating the fake stones with a different seed and/or density seed and you may be able to get your camera field of view to look at only good fake stones.

Cheers  -Bill

[Dune]

I wish we had a "blurring" node for some things but apparently this cannot work in this TG2 node world

I was just thinking about this, and needing it badly for a project I'm working on. Is there no way to blur a mask (stones, PF...)? Maybe some blue nodes.... Anyone?

[Franco-Jo]

Thanks very much for all of your suggestions! I'll press on with them and see how it goes. 

[bobbystahr]

I wish we had a "blurring" node for some things but apparently this cannot work in this TG2 node world

I was just thinking about this, and needing it badly for a project I'm working on. Is there no way to blur a mask (stones, PF...)? Maybe some blue nodes.... Anyone?

I'm afraid what we need here may be the illusive full grey scale transparency from the Alpha channel like almost every other 3 D app on the planet has....nuff said .  ..   ...

[Tangled-Universe]

I wish we had a "blurring" node for some things but apparently this cannot work in this TG2 node world

I was just thinking about this, and needing it badly for a project I'm working on. Is there no way to blur a mask (stones, PF...)? Maybe some blue nodes.... Anyone?

I'm afraid what we need here may be the illusive full grey scale transparency from the Alpha channel like almost every other 3 D app on the planet has....nuff said .  ..   ...

I see the point you're making and I think I agree with you that TG2 still lacks this essential ability. However...
The renderer is perfectly able to work with grey-shades. I think it doesn't work with alpha channels because those are being raytraced and that that part of the renderer isn't made suitable to handle greyscale transparency yet.
For example, raytracing is also used for calculating the terrain shadows.

In the context of this topic it is not relevant. You "blur" PF's by using a low contrast value, for example.
However again, if you have a sharp fractal and would like to blur it then that's not possible like Dune pointed out.
(he probably wants sharply defined areas with stones, but with blurred edges to avoid weird stones)
It would require a procedural based blur function to do that which isn't available as well yet, though I think not extremely easy to apply on planetary scales.

[bobbystahr]

I wish we had a "blurring" node for some things but apparently this cannot work in this TG2 node world

I was just thinking about this, and needing it badly for a project I'm working on. Is there no way to blur a mask (stones, PF...)? Maybe some blue nodes.... Anyone?

I'm afraid what we need here may be the illusive full grey scale transparency from the Alpha channel like almost every other 3 D app on the planet has....nuff said .  ..   ...

I see the point you're making and I think I agree with you that TG2 still lacks this essential ability. However...
The renderer is perfectly able to work with grey-shades.

Too cool. I wasn't aware of this...really good info T U...many thanks for clearing my brain on that .  ..   ...

[Dune]

(he probably wants sharply defined areas with stones, but with blurred edges to avoid weird stones)

Not necessarily; I want to use the stones themselves as a mask, but blurred.

[Tangled-Universe]

(he probably wants sharply defined areas with stones, but with blurred edges to avoid weird stones)

Not necessarily; I want to use the stones themselves as a mask, but blurred.

I did that too once to avoid grasses from sticking through the stones and it worked kind of ok, but not perfect.

If I recall correctly I connected the output of the stones network (the final merge shader) to a "colour to greyscale colour" node.
That I connected to a colour adjust and increased the whitepoint to expand the mask (work in shader preview I'd suggest).
I used that inverted as a blendshader for my grasses. A lot of grasses disappeared around my stones, though not all.

It's not really blurring of course, but it's something

[Dune]

Funny, that's exactly what I did, until the last node.