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Messages - Richard O'Konski

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PyroSim / Re: ERROR: Output QUANTITY VISIBILITY requires a SPEC_ID
« on: December 15, 2011, 09:55:13 am »
Your observations are correct.  The quantity, VISIBILITY, is only valid when you either include a SPEC_ID on the same record or invoke the mixture fraction model in FDS, such as by including a fire.  When you use this quantity without a species and without specifying a fire, FDS complains.  

PyroSim used to detect this situation and write out an unused surface (INERT_FIRE) that forced FDS to invoke the mixture fraction model.  Due to a regression in our latest release, however, this was no longer happening.  When you changed the smoke quantity to a species Mass Fraction (which also requires the mixture fraction model), PyroSim still worked in detecting this and included the INERT_FIRE surface.  That's why it started working when you changed the smoke quantity.

Thanks for reporting this regression.  The next release of PyroSim will include a fix for this.

PyroSim / Re: Revit model export to Pyrosim?
« on: July 01, 2011, 07:44:37 am »
We had not heard of IFCOpenShell before, but it looks like it might be a viable solution. 

When we first looked into IFC import a couple years ago, we were actually thinking about taking an approach almost verbatim what they did in IFCOpenShell - use Open CASCADE to support the IFC geometry.  This would have been a significant development effort, however, considering the vastness of the IFC standard and the sheer numbers of geometry types that would have to be supported.  During our PyroSim development cycles since then, we haven't had enough reason to spend that time when we already supported DXFs that got us 90% of the way there for BIM support. 

Now that someone has done this work on IFC, however, we might be able to incorporate it into our software with little expense (depending on IFCOpenShell's license).  Thanks for the heads up!

Pathfinder / Re: Pathfinder: Fatal Error
« on: April 18, 2011, 07:24:19 am »
This dll will not work with PyroSim.  We'll be releasing a patch for it later today.

Pathfinder / Re: Pathfinder: Fatal Error
« on: April 13, 2011, 08:59:23 am »
Thanks for doing some debugging on your end. 

What you've found seems to confirm what we've seen in the office as well: each texture dimension must be a multiple of four on these ATI cards when using texture compression. 

I re-read the spec for the texture compression extension, and it turns out that it is a little vague about the rules when using texture compression.  In some spots it says that the image dimensions must be multiples of four, but then there is a note that if the card supports non-power-of-two textures (which your card does), the dimensions don't have to be multiples of four.  Apparently ATI just stuck with the multiple-of-four rule, however.

We'll incorporate fixes to our products in the coming months (there should be one soon for Pathfinder since we're currently on a release cycle for it).  In the meantime as a work-around, make sure your image dimensions are multiples of four, and you should be okay.

Pathfinder / Re: Pathfinder: Fatal Error
« on: April 11, 2011, 09:39:18 am »
What version of Pathfinder are you using?  You can determine this by going to Help->About (assuming you can open Pathfinder at all).

PyroSim / Re: Invisible
« on: March 18, 2010, 08:20:41 am »

If you hide the object in PyroSim by right-clicking the object and selecting "Hide Object(s)", then the object will also be "Invisible" in Smokeview when you run the simulation again.

Richard O''Konski
Thunderhead Engineering

PyroSim / Re: orifice diameter
« on: May 27, 2009, 01:03:26 pm »
The current release of PyroSim does not support the ORIFICE_DIAMETER property, but the next release (due in late July to early August) will.

To work around this issue in the meantime, you can define your sprinkler and its properties in the "Additional Records" section of the "Record View."


We've looked into this problem and found that there was a bug calculating the actual velocity of occupants for each time step.  We hadn't seen it in any of our testing, but it crept up in your simulation.

What happened was that the velocity was exponentially increasing past the maximum velocity of the occupant.  He couldn't slow himself down, and so he was actually zipping around in the model rediculously quickly.  He eventually gets stuck in a corner of a room because he was moving so fast relative to the time step that he couldn't navigate through the door and out to the exit.

The fix will be in the next release, which should be tomorrow.

Pathfinder / Re: Create movie...
« on: February 25, 2009, 11:42:13 am »
We've looked into the problem with codecs a little further, and we've found the following:

1) Xvid doesn't play fairly with some resolutions (e.g. 640x480, 1280x720, etc.).  We've modified our code, however, to make it work.  This change will make it into our next Pathfinder release.

2) The ffdshow codec (which is free) seems to work reliably.

3) Some codecs require you to specify a video resolution that is a multiple of 4 for both width and height.  Many codecs require that it at least be a multiple of 2.  This is most likely the problem that liu_zhen was experiencing, since his height was 585.  The current release of Pathfinder warns you if the width does not match this criteria, but it does not warn about the height.  Our next release will warn about both.

Pathfinder / Re: Sloped Seating
« on: February 13, 2009, 10:34:30 am »
I'm not exactly sure how your theatre is layed out, but I'll assume you have some flat portions that I'll call landings and some ramps connecting those landings. There are a couple options available to create this:

1) If your dxf is 3D you can use the 3D room extraction tool in the 3d view.  To use it, click the button labelled "Ext."  Next click somewhere on the floor. The room with ramps should be created automatically.
2) If you have a 2D dxf, then you can use the 2D floor extraction tool to make the landings and then connect the landings with stairs to make the ramps.  To use the 2D floor extraction tool, for each landing select the lines in the dxf that make that landing, and from the "Model" menu, select "Extract Rooms..."  To make the stairs (ramps), use the two-edge stair tool.

If you do not want to use stairs to make the ramps, another method is to make a room and rotate it about the X or Y axis.  This method is a bit trickier, however, because you'll either need to place doors between the "ramps" and their adjoining rooms or merge the ramp and rooms into one room.  In either case, the ramp and room need to line up nearly perfectly.  I've attached a file that demonstrates this method of creating ramps.

Pathfinder / Re: stair problem
« on: November 14, 2008, 09:36:59 am »
You didn't do anything wrong.  We've found that the one-point stair tool is a little trickier to use than the two point because we have such a tight tolerance for determining whether a stair is touching a room.  Right now the edges of the stairs have to match very closely to the connecting room in the z coordinate. 

Because the z coordinate of your stair is an irrational number, the best way to accomplish this is to "select" the z location for your room.  To do this, make sure the edge of the stair you want to connect to is visible in the Perspective view.  Then select a room tool.  In the property panel for the tool there is a button next to the "Z Plane" field that says "Select."  If you click this button you can graphically choose any point in the Perspective view and the "Z Plane" will be extracted from the z coordinate of the selected point.  So go ahead and click the "Select" button and then click the top edge of the stair.  The Z Plane will now be filled in with the appropriate value, and the next drawn room should connect appropriately to the stair. 

To double-check that your new room is connected to the stair, you can right-click on the room or stair and select, "Select Connected Components."  All the rooms, stairs, and doors that touch the item will now be selected.

The next beta release will hopefully help with some of these stair issues.  We've added "handles" that let you edit geometry.  One of these handles is one that let's you easily connect existing stairs to a room if they do not already touch.

Pathfinder / Re: Same input file, different answer
« on: August 29, 2008, 10:00:04 am »
In regards to agents becoming stuck, this may either be because of the adaptive behaviors or because of a bug we recently found with clipping internal edges.  When running a simulation, we currently keep occupants away from walls by clipping internal triangle edges away from boundaries.  Unfortunately, there was a bug with this edge clipping that made it into the beta just before it was released.  I believe this was the cause of the strange behavior with occupants becoming stuck or repeatedly running into walls.  We have since fixed this bug, but unfortunately, it's been difficult to determine whether it was the cause of the stuck agents because every simulation produced different results (sometimes the agent would be stuck, sometimes not).  So far, through our internal testing, we haven't experienced any more stuck agents.  This fix for the edge clipping will also be in the next beta.

Pathfinder / Re: Pathfinder floor adjustability
« on: August 01, 2008, 01:44:35 pm »
There are actually no bugs with how floors are working right now. 

Floors are merely filters for 3D imported geometry (from DXF and FDS files) and groups for Egress geometry (rooms, doors, stairs, etc.).  This means that any Egress object you add to a floor is always going to be visible if the floor is visible and the object is visible no matter what the current floor filters are.  Any 3D geometry in the model, however, is clipped away based on the visible floors' filters.

The problems Charlie experienced arose because he expected the filters to clip both 3D imported geometry AND Egress geometry.  In addition, Pathfinder always requires at least one floor, so when Charlie tried to delete the only floor in his model and it remained, he thought this was a bug.

Since the current behaviour is not as intuitive as we hoped, we would appreciate suggestions from users as to how we can improve the floor feature.  What is good and what can be improved/changed?

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