Changes of values and a blooper

Started by j meyer, June 08, 2009, 09:21:03 AM

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j meyer

Hi,
there are still occasional changes of values.The last one i noticed was
in a Power Fractal.It changed from 50 to 79.8459 and that does make
a difference.Probably happened on saving.(built 20031,Vista 32bit)

And another somewhat annoying thing,more of a blooper though,is
everytime i try to load a heightfield the window that allows you to
assign a .ter file opens correctly,but along with it there comes an
error message telling me that TG can't locate the file.That's before
the user had the chance to assign one,which is a little bit early,at least
from my point of view.No matter if you do it from the node view or the
add terrain feature.

Oshyan

I'm still unable to reproduce the "change of values" issue, so it's rather hard to fix without that. I'll keep trying though. If you can nail down a solid way to reproduce it, that would be great. If it comes up again, see if you can retrace your steps.

I'm not getting the problem with loading heightfields either. How are you adding the Heightfield Load?

- Oshyan

j meyer

As for the change of values:in this case i had a node array (5 or 6 nodes),which
were copied and then pasted into the Internal Network of a TG sphere.Two of the
Power Fractals (with the same seed) had the Smallest scale set to 50 before the
copy and paste action and afterwards aswell.Then i saved the TG sphere as a
clipfile.After that i started a new scene and loaded the clipfile,went into the
Internal Network and found the Smallest scale being 79.8459 now.
I still have the original file and the clipfile in case...

Usually i rightclick on the Generate heightfield node and choose Load heightfield
from the menue that pops up,but i've tried it via the add terrain button also.Same
result both ways.

Matt

#3
Smallest scale is linked to the number of octaves, which makes it possible to use certain values only. When you change the smallest scale, it figures out the number of octaves to use. (It also has to do this if you change the other scale settings.) But really, the number of octaves is the final instructor to the shader for how much detail to use. The smallest scale might change when you reload a file, clip file, or paste a copied node, but it shouldn't have any effect on the rendered result. If the render changes, then that's a bug we need to fix.

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

j meyer

See attachment please.

Matt

#5
Hmmm.. we have a bug then :)  Can you copy the fractal shader node in here, (or the whole .tgd) so I can work with exactly the same example please?
Just because milk is white doesn't mean that clouds are made of milk.

j meyer

Attached is a folder containing:
1.the tgc of the sphere with the changed values (79.8459)
2.the tgd with the correct values that i've used to render the above
example changing the values manually.
3.a screenie of the nodes where the 2 PFs in question are highlighted.

Thanks for looking into it,J.

Matt

#7
Hi J,

I can't reproduce the problem. I do the following:

Load your .tgd file: The two fractals you highlighted have smallest scale = 50, octaves = 7. I take it that these are the values you want.

Load your .tgd file, set the smallest scale to 79, which results in octaves = 6. Save a new .tgd file. Load the new file, and the values are exactly how I saved them (79 and 6).

Load your .tgd file (which has 50 and 7). Copy the sphere, paste. Inside the copy, the values still are 50 and 7. Save a clip file from this, reinsert the clip file. The values in the inserted clip file are 50 and 7.


Is there something else I should try? Maybe there's still a bug somewhere which caused things to change, but I can't figure out where in your steps that happened. The only thing that I know will change the smallest scale to 79.8459 is manually changing the number of octaves to 6, but I don't know how that happened.

[Update: the number 79.84589974 is in your clip file, so if there is a bug it must have happened before saving the clip file or during the save]

Matt


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

j meyer

Indeed it (the change) seemed to happen during the save as mentioned
in my first post.I saved the clip from another tgd,which i also kept.So in case
you want to take a look at that one too,i can post it later today.

The tgd in the zip was just the one i used to demonstrate that there is
a difference between Smallest scale 50 and 79.8459.

Sorry for causing any inconvenience,J.

j meyer

I have to apologize again,i can't say which file exactly it was that i started
with,because i have two versions of the same file one with the other without
displacement and i am not a 100% sure which one i used,so i'll attach both,
sorry.
And there is a little mistake in the description of what i did (my 2nd post from
above),so here comes the corrected version:loaded the file->loaded a TG sphere
->copied/pasted the nodes from the Shaders group into the internal network of
the sphere ->divided the scale settings of the Power fractals by 10 ->set the
size and height of the sphere to 12 ->did a test render and then saved the
sphere as a tgc.And there it -probably- happened ----in this case,in other cases
changes occurred while working on some other feature,for example i changed some
noise setting or so and when switching back to the scale tab i found a new value.
I haven't seen a clear pattern why and when it's happening,though.
Thanks again,J.

Matt

#10
If you make changes to the feature scale, the number of octaves isn't updated properly. It is supposed to update whenever feature scale is greater than lead-in scale (because the number of octaves is a function of the ratio of smallest_scale to max(leadin_scale, 2 * feature_scale). That may lead to unanticipated behaviour when a file is saved, copied/pasted etc. although I'm not sure yet. I'll see what I can do.

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

j meyer