Generate Sample set with texture map

[snowctrl]

Hi there

I'm using the Generate Sample Set node to spread points across a surface, but I can't get the Filter Attribute to accept a texture map, only a weight map

For the scene in question a texture map is necessary

The manual says Generate Sample Set's Filter Attribute should accept Integer or Scalar data - is there a way I can set up a texture map to deliver Integer or Scalar rather than Color data?

Alternatively is there a similar node or different version of Generate Sample Set that will accept a texture map?

Help appreciated - I'm at a loss...

[gotchee]

hey,

why don't you just filter the points after your sample set? As it's executed on Emission it shouldn't make a difference performance wise.

hope this helps,

cheers

[snowctrl]

errr... I was presuming it would give a hit performance wise.... I will have to test

Thanks

jON

[Tekano]

you need to 'apply' a texture map to the object you are wanting to filter by.

it is not your usual texture with projection (for rendering) but a special map that can be read by ICE , envelopes and hair etc.

select your object then property>texture map assign texture and UV's etc. your particles should now have access to the texture map color property

[gotchee]

okay,

seems i was living a lie
i just made a quick test using a weightmap and then using a corresponding texture map.
the weightmap was used to filter directly in the generate sample set and the texture map was used as shown in my previous screenshot. seems there is quite a time difference. the texture map way is about 10 times slower. although we are talking about milliseconds. i was filtering 1 million points down to 200000 and had 70ms for the weightmap filtered stuff and 700ms for the texture map filtered one.

but if you are forced to use a texture map, i'd still go with this way

cheers,

michael

[snowctrl]

Thanks Michael - you got to testing it before I did!!!

My logic was that by Filtering by Texture Map, ICE will create the max number of particles, then throw them away again if the texture map filters them - I was hoping to speed things up by having Generate Sample Set only generate the points I want, where I want them

Call me fussy....



jON

[snowctrl]

you need to 'apply' a texture map to the object you are wanting to filter by.

it is not your usual texture with projection (for rendering) but a special map that can be read by ICE , envelopes and hair etc.

select your object then property>texture map assign texture and UV's etc. your particles should now have access to the texture map color property

Hi Tekano

I am already applying the texture map to the object by way of Get->Property->Texture Map->Texture Map - I presume this is what you mean?

It doesn't seem to work... I'm using 2013, but have tried in 2014 also

I figured the data type is the issue - I need a way of getting a texture map to deliver integer or scalar data rather than color, or a different Generate Sample Set node

... unless you know different? I'm still very much an ICE novice...

Is there an image file format that I can save from Photoshop that Softimage will interpret as Scalar or Integer?

Thanks

jON

[gotchee]

yes sure,

initially i would do the same . because as you said, why create point in the first place just to delete them right after that
i just hoped ICE would be as optimized, that when you do stuff "On Emit" it would have the same effect as filtering directly in the sample set. but one can only dream

[gotchee]

just another thought...

why don't you create an ICE-tree on the emitter object. where you just "convert" the texture map color to e.g. brightness and set this as a scalar attribute.
works in my test setup and is almost as fast as filtering with a weightmap!

[snowctrl]

EXCELLENT, I have it working!!

Many thanks for your help

It didn't work properly initially until I (like in your image) moved the Ice tree up to Shape Modelling in the Modifier Stack - this has me stumped, I don't suppose you could point me to somewhere that would explain why this needs to be this way?

Thanks again

jON

[gotchee]

cool! good to hear it works on your side!

concerning the problem with the stack...that's strange. i just moved the tree up, because i wanted to freeze the modeling stack. now when i move it back down, it still works...wierd.

might be something with what you do in your modeling stack, that it needs to be in the shape stack!?
anyways, as long as it's not a problem to move it there, i would do so

all the best,

michael