Index Field

[Pazuzu]

Hi!!

Its possible that someone explain to me, what exactly does the index field in a gas calculate microsolver when two fields are processed? in the help says that the index field stores the object id, but i don´t understand what exactly does.

Thanks.

[Pazuzu]

!!Solved!!

The index field stores property values like temperature, collision, velocity, etc; fetch from the object with help of a gas build relationship mask node.

[chumbuk]

but "index field" have integer type value for voxel, so "index field" don't have stored temperature, collision, velocity, may it is stored index source if it is are many

[bareja]

Indeed, it looks like index field is array of integers, index field visualization has 'index to visualize' parameter, so i guess we can choose array index. Of course i'm not sure.

Check the example. In scene just turn off Use Plane in indexfieldvisualization1 node, then changing Index to Visualize u can visualize specified index. Maybe in gas calculate when we changing source property we are changing array index in index field. I'm just thinking loudly.

[bareja]

Example file, I've forgotten.

index_field_example.hip

[bareja]

I've found in information in help:

Index to Visualize - If not using Plane visualization, an iso surface will be built at this value. It will surround the volume of the field that has a value equal to the index value.

So it means that is not array of integers, it contains integers and builds visualization when index == value

[bareja]

This example explains everything.

index_field_example3.hip

[bareja]

Or maybe this

index_field_example3.hip

[Pazuzu]

Thank you very much!!!!

[bareja]

Thank you too i did't know what for is Index Field and now i know

[Pazuzu]

I have notice that you have grouped points directly with "wildcards" inside the group parameter of the point sop to select the points with negative values, i didn't know that this can be possible....Great!!!

@vs<0

[bareja]

Read in help about Name SOP there is a lot information about it, how faster is it.

[bunker]

Nice one Bareja, really useful stuff

Or maybe this

[chumbuk]

I think that is the number of sources(or pumps), but the influence on the simulation is empty, if you remove it or change the value

index.hip

[bareja]

hey! yea in my example you can see how gas calculate reads property form geometry using index field, because that was the question

[chumbuk]

hey Piotr. I understand how to read the value of the index fields and use them later, it is obviously. Puzzle for me as their uses in pyro and smoke solver components, such as Gas advect or gas nondivergent project, i think it is for separate and collide fild for different sources, but it's my thinks

[chumbuk]

I meant "collisionindex" in gas feedback and enforceboundary))) In general if we are having this issue, we must examine other additional field sourceindex, collisionvel, pumpindex.I guess that they are used as a mask, but what kind of mathematics we need to understand.

[chumbuk]

index(source collision pump) field allow extracted phisical parametrs from geometry objects like velosity temperature etc. index field is like mask and don't consist of value of this atributes. Attributes can extracted with Gas Calculate dop. Very interesting, how can do this with Gas Fiel vop ? Or it is are posible only wit gas calculate dop?

index2.hip

Edited July 20, 2010 by chumbuk

[bareja]

Hi,

maybe this way,

it is not finished i just give an idea.

cheers.

gas_calculate_replacement.hip

Edited July 20, 2010 by bareja

[bareja]

check this file now it's correct

annotation:

Just add object named source0, source99 etc... with volume data called Geometry, and it will be work.

gas_calculate_replacement.hip

Edited July 20, 2010 by bareja