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loopyllama

Temperature visualization from pyro .bgeo?

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There must be a way to visualize temperature, heat, burn, etc from a .bgeo written from a pyro simulation, but I can't find it. I seen the videos, I have searched the forums. I can visualize density from a .bgeo (it is group "0" in my .bgeo). I can visualize all the fields in a dop network Smoke Object as well. I can't seem to get the .bgeo data into a Smoke Object or get something besides density in SOPs.

In the extended information of my .bgeo I see "Volume Resolutions" and it has 12 primitives. That must be my data!

I have attached the 5th frame .bgeo from the sim.

What am I missing/forgetting/not understanding?

pyrofields.0005.bgeo.gz

Edited by loopyllama

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Good question, I'd like to know too :)

When you create a volume you can set it's visualization style.

In your bgeo the density volume is set as "smoke" and the rest as "invisible"

(actually there is another one set as "smoke", but it is negative and thus not visible (i guess))

Is there a way to change the visualization style of an existing volume?

A dirty way is to make a new volume and copy the contents of the existing volume into it, but that's a bit ugly..

(See attached .hip)

--

While looking into this I converted the bgeo to an ascii geo and found myself wondering about the order of the

volume primitives. If I look at the loaded bgeo in spreadsheet the primitive numbers are:

0 density

1 vel.x

2 vel.y

3 vel.z

4 rest.x

5 rest.y

6 rest.z

7 rest2.x

8 rest2.y

9 rest2.z

10 temperature

11 heat

12 fuel

And in the geo file the name index attribute is:

name 1 index 13 fuel heat temperature rest2.x rest2.y rest2.z rest.x rest.y rest.z vel.x vel.y vel.z density

Which seems to be the reverse, but with the 3-element volumes in their correct internal order.

Why is it reverse?

Looking at the the following volume run in the geo, the first (index 0) volume seems to be the density.

(The last volume looks otherwise possible as well, but its vis type is "invisible" while first is "smoke"..)

Why does it match the last index in the name list with the first volume?

I didn't see any mention in GPD.txt of either an index list or a run being reverse in sense.

eetu.

volumevis.hipnc

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There must be a way to visualize temperature, heat, burn, etc from a .bgeo written from a pyro simulation, but I can't find it. I seen the videos, I have searched the forums. I can visualize density from a .bgeo (it is group "0" in my .bgeo). I can visualize all the fields in a dop network Smoke Object as well. I can't seem to get the .bgeo data into a Smoke Object or get something besides density in SOPs.

In the extended information of my .bgeo I see "Volume Resolutions" and it has 12 primitives. That must be my data!

I have attached the 5th frame .bgeo from the sim.

What am I missing/forgetting/not understanding?

One way to do it is use a Blast SOP to delete everything but the volume primitive that you want (Delete Non Selected), using a group expression that references the "name" attribute, so something like:

@name="temperature"

Then append a Primitive SOP, and on the Volumes tab click "Adjust Visualization", which lets you change the Display Density, use rainbow smoke etc. Toggling that on seems to tell Houdini you want to visualize that particular volume using the default density-type display.

Another thing I've done is to recreate the "Plane" visualization from DOPs in SOPs, which you can do pretty easily with a Grid SOP set to some expressions to match the size and resolution of the volume and a VOP SOP using Volume Sample to map the volume values to a color Ramp.

See attached for an example of both.

viz_temperature.hip

Edited by johner

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Ahh, yess, thanksies!

eetu.

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