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91
Terragen Discussion / Re: Speed of downloading images on these forums
« Last post by Dune on October 15, 2018, 06:00:57 AM »
132ms and a timeout at hop 7....  ???
92
Thanks for the clarification! My normal approach is to mask the Density Fractal but now I will try this approach.
On what conditions do you consider using a Cloud Density Fractal to drive the Depth Modulator?  Most cloud .tgcs that I have studied usually leave this blank although some use it.  When I have experimented with adding a Cloud Density Fractal to the Depth Modulator, the cloud (mostly cumulus) decreases significantly in size.  It is something that I wasn't sure how to control.

It is basically the depth of the cloud, modulated. So white (1) would be the maximum, and black (0) the minimum, which I believe can be exceeded (<0 would be no clouds). So that is why the clouds look smaller because what isn't white (1) will push the clouds down. This can be handy for adding extra folds to the clouds or modulating the shape while retaining the original fractal detail with larger subtle differences like with a perlin soft shader.
93
Image Sharing / Re: More Columnar
« Last post by Antoine on October 15, 2018, 05:31:59 AM »
Very nice scene !

Quote
Yeah, I'm confused why the shadows seem so dark as well

When using path tracing, I have noted that there is a bigger contrast between sun and shadows which often look too dark. To remedy this I set the power of the sun from 5 to between 3 and 4, and I raise up the exposure slider a little until shadows are looking good enough.

David
94
Terragen Discussion / Re: Speed of downloading images on these forums
« Last post by WASasquatch on October 15, 2018, 05:02:38 AM »
We're still reading and understanding this stuff differently, it seems (including Wikipedia). A server can be configured to forward the packet but not send an ICMP response to a ping request on timeout. If a hop fails, it does *not* kill the sequence inherently (that's obvious because, uh, look at Martin's screenshot, there are servers that follow it). Rather, the tracert function sends another request with an incremented TTL and the server that didn't send back a response to ping may *still* forward that request to the *next* server.

Your update to the reply above basically agrees now with what I'm saying:

Quote
When it hits the control path on a physical router it will almost 100% of the time be dropped unless it's idle. In fact without custom roms I don't think you can even change this low priority behavior unless using a actual server as a core firewall for the data center / network. This is because the CPU of a router is designed specifically for it's data path usage and has hardly any control path power.

That right there says that a timeout is *not* necessarily indicative of any problem - of a part of the route that is "not working right or unusually slow" - because most routers are not going to be idle.

- Oshyan

The timeout is because their is no response, not because the request has been altogether blocked. The request continued on it's path. That's why the wikipedia specifies a second attempt if all three timeout and it can't continue on it's route (which you can see in your network activity). If it continues on it's route, there is no need to try again, and just list the timeouts, as it got no reply.

A firewall will either accept or not accept these packages. If it doesn't accept them, the route is blocked at that point. I'm not aware of any "Deny but Reply" flag. It's based on a 0/1 flag. You can reroute the request somewhere else that would reply. But none of that helps diagnose network issues and isn't a standard thing to do in the least. An example of this is my old host datashack, you could not ICMP the data-center, but they would pass-through to a specific server if that was the destination.

A router also can handle tons (like enough to handle networks like Facebook and such) of data paths, so if it's getting to the control path, inherently, it's blogged down, Oshyan. If requests are constantly hitting the control path and relying on priority, there is most certainly a network issue and the router is overloaded.

Additionally, here is a couple more tracerts to planetside and you can see hop 6 (with networklayer) I get a timeout, but not always, but than again, I get timeouts visiting planetside occasionally for no reason almost immediately, and that server could be the reason unless planetside is going down occasionally briefly, but likely, like most the time, it's a network thing.
95
Terragen Discussion / Re: Speed of downloading images on these forums
« Last post by Oshyan on October 15, 2018, 04:19:45 AM »
We're still reading and understanding this stuff differently, it seems (including Wikipedia). A server can be configured to forward the packet but not send an ICMP response to a ping request on timeout. If a hop fails, it does *not* kill the sequence inherently (that's obvious because, uh, look at Martin's screenshot, there are servers that follow it). Rather, the tracert function sends another request with an incremented TTL and the server that didn't send back a response to ping may *still* forward that request to the *next* server.

Your update to the reply above basically agrees now with what I'm saying:

Quote
When it hits the control path on a physical router it will almost 100% of the time be dropped unless it's idle. In fact without custom roms I don't think you can even change this low priority behavior unless using a actual server as a core firewall for the data center / network. This is because the CPU of a router is designed specifically for it's data path usage and has hardly any control path power.

That right there says that a timeout is *not* necessarily indicative of any problem - of a part of the route that is "not working right or unusually slow" - because most routers are not going to be idle.

- Oshyan
96
Thanks for the clarification! My normal approach is to mask the Density Fractal but now I will try this approach.
On what conditions do you consider using a Cloud Density Fractal to drive the Depth Modulator?  Most cloud .tgcs that I have studied usually leave this blank although some use it.  When I have experimented with adding a Cloud Density Fractal to the Depth Modulator, the cloud (mostly cumulus) decreases significantly in size.  It is something that I wasn't sure how to control.
 
97
Terragen Discussion / Re: Speed of downloading images on these forums
« Last post by WASasquatch on October 15, 2018, 03:57:19 AM »
Your understanding differs from mine. Tracert is basically pinging all servers from you to a destination server and requesting a response. If a server is configured to not respond to ping (ICMP) requests, it will time out. Many servers are configured this way for security or other reasons and will thus result in a timeout. ICMP is also generally a low priority request so yes, congestion may also result in a timeout. I've seen one or two timeouts in many tracerts I've run over the years, it seldom indicated an issue, and often persisted over many routes to the same end point. It almost certainly indicated a server that was configured not to respond for whatever reason.

From Microsoft themselves:
Quote
Request Timed Out
This message indicates that no Echo Reply messages were received within the default time of 1 second. This can be due to many different causes; the most common include network congestion, failure of the ARP request, packet filtering, routing error, or a silent discard.
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc940095(v=technet.10)

Additionally, from ServerFault:
Quote
Routers can be configured to not respond with an ICMP message that traceroute depends on. Also, MPLS can do that because it is not routing, it is label switching.

When a router needs to create an ICMP message to send back to the source host, that is a low priority task that it may no get around to in time. Also, some router administrators don't want their busy routers to even need to spend cycles doing that, so they disable it altogether. It could also be that network administrators don't want to give away that information.

So a timeout on a *single* host may not mean anything at all.

Quote
There is only one real instance when a timeout on a traceroute is a bad thing. That is when you see timeouts that continue forward in the route. By that I mean when you see an individual timeout and then many more after that. There are two main instances when this can happen, the first and most common is that there is a firewall that was configured to block these packets in the route. The other instance is that a router is dropping packets going THROUGH it (i.e. Forwarding Plane(arms) packets) and this is can be a VERY bad sign. This is usually caused by one of three reasons either the router is overloaded, the router having a software or physical failure or the router is configured to do this(null route/blackholes).
https://www.hostdime.com/resources/trace-routes-timeouts/

- Oshyan

What you're failing to understand is if the router doesn't handle ICMP requests, the entire tracert command aborts, so it would end  there, and you'd know there is a firewall block/routing loop/misconfiguration at that router. "Traceroute proceeds unless all (three) sent packets are lost more than twice, then the connection is lost and the route cannot be evaluated" Wikipedia. If the three pings are lost, it tries again, if those three requests fail, it aborts.

It can't get to the next host if it's been blocked, which is why the command aborts..

For example, if I do not use my VPN, and use MetroPCS, tracert will be blocked by the first route, and abort, as my ISP doesn't allow ICMP requests.

Most servers in the commercial world don't block ICMP requests or even UDP or TCP requests of the echo nature, because of debugging concerns of networks and global reach.

And it's simply by about 1000 fold, that the router is just ignoring the request and passing it through (control path) rather than replying, because it's busy. When it hits the control path on a physical router it will almost 100% of the time be dropped unless it's idle. In fact without custom roms I don't think you can even change this low priority behavior unless using a actual server as a core firewall for the data center / network. This is because the CPU of a router is designed specifically for it's data path usage and has hardly any control path power.
98
Terragen Discussion / Re: Speed of downloading images on these forums
« Last post by Oshyan on October 15, 2018, 03:45:25 AM »
Your understanding differs from mine. Tracert is basically pinging all servers from you to a destination server and requesting a response. If a server is configured to not respond to ping (ICMP) requests, it will time out. Many servers are configured this way for security or other reasons and will thus result in a timeout. ICMP is also generally a low priority request so yes, congestion may also result in a timeout. I've seen one or two timeouts in many tracerts I've run over the years, it seldom indicated an issue, and often persisted over many routes to the same end point. It almost certainly indicated a server that was configured not to respond for whatever reason.

From Microsoft themselves:
Quote
Request Timed Out
This message indicates that no Echo Reply messages were received within the default time of 1 second. This can be due to many different causes; the most common include network congestion, failure of the ARP request, packet filtering, routing error, or a silent discard.
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc940095(v=technet.10)

Additionally, from ServerFault:
Quote
Routers can be configured to not respond with an ICMP message that traceroute depends on. Also, MPLS can do that because it is not routing, it is label switching.

When a router needs to create an ICMP message to send back to the source host, that is a low priority task that it may no get around to in time. Also, some router administrators don't want their busy routers to even need to spend cycles doing that, so they disable it altogether. It could also be that network administrators don't want to give away that information.

So a timeout on a *single* host may not mean anything at all.

Quote
There is only one real instance when a timeout on a traceroute is a bad thing. That is when you see timeouts that continue forward in the route. By that I mean when you see an individual timeout and then many more after that. There are two main instances when this can happen, the first and most common is that there is a firewall that was configured to block these packets in the route. The other instance is that a router is dropping packets going THROUGH it (i.e. Forwarding Plane(arms) packets) and this is can be a VERY bad sign. This is usually caused by one of three reasons either the router is overloaded, the router having a software or physical failure or the router is configured to do this(null route/blackholes).
https://www.hostdime.com/resources/trace-routes-timeouts/

- Oshyan
99
I regularly refer to the wiki page, which is very helpful sometimes.  For the inputs I mentioned, there is no info.  What is the difference between the Density Shader and the Final Density?  Why would one choose to use it?  There must be an intended purpose for all three inputs.  I prefer to have an explanation instead of experimenting blindy.

@ WASaquatch.  I appreciate your experimentations, and it is helpful feedback, I was hoping to find some better answers by disecting this .tgd file.

Like I had mentioned, the Final Density is the "Final" Density, like a mask. You can supply a Density Fractal and then mask it out, which seems to provide smoother results than masking the Cloud Fractal before plugging into the Density Fractal, and masking however many nodes you have to supply to Density Fractal...

From the Wiki
Quote from: Planetside Wiki
Final density modulator: The Final density modulator is masking the cloud density shader

https://planetside.co.uk/wiki/index.php?title=Cloud_Layer_v2_-_Functions_Tab
100
I regularly refer to the wiki page, which is very helpful sometimes.  For the inputs I mentioned, there is no info.  What is the difference between the Density Shader and the Final Density?  Why would one choose to use it?  There must be an intended purpose for all three inputs.  I prefer to have an explanation instead of experimenting blindy.

@ WASaquatch.  I appreciate your experimentations, and it is helpful feedback, I was hoping to find some better answers by disecting this .tgd file.
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