How Do You???

[Thelby]

How Do You keep your populations from going under the terrain from little to a lot???
I have a render going and it is now appearant that some of the bushes are somewhat under the top of the surface. 

[cyphyr]

Displacements after the compute terrain node in the Terrain group can throw off the accuracy of the object placement. To fix this place a new Compute terrain as your last node in your Shaders group.

Incidentally this will move all your shaders to your Terrain Group. When viewing (clicking) on the top row of tabs, there will be no shaders under the shader tab if the last shader is a compute terrain tab although they will still be in the shader group. A little confusing and I'm not sure if this is a new err "feature" but it makes no difference to your final output, it just moves nodes to places unexpected!

Hope this helps

Richard

[Thelby]

Confussing Yes!!!
I just tried on another machine to pull up the Population and it made no difference, then I tried to elevate via Y axes by increasing the number and again No Difference. I thought that the populated objects were to sit on top of the terrain no matter where they were popultaed or no matter the terrain height differences. I am wrong to assume that's the way it should be?

[Thelby]

OK, I am having trouble locating the 'Compute Terrain' shader.

[dandelO]

Just use the final surface shader in the shaders tree as the 'terrain shader', that'll work, and there's no need for extra compute terrains, that'll make extra render time.
It would probably be more 'correct' to use Richards way, mind. It's not usually needed, though.

[Thelby]

Geezzz, now I am really confused. I can't find the QUOTE: Terrain Shader :UNQOUTE.
Is it any ole shader I can use?

[cyphyr]

The Terrain Shader is the Fractal shader (or whatever terrain displacement your using) in your Terrain group

Richard

[dandelO]

What I meant was, plug the last surface shader of the 'shaders' group into the 'terrain shader' input of the populator...

[attachimg=#]

The little hand is pointing to the input I mean, if you hover over that with your mouse cursor in the node network, 'terrain shader' will pop-up as a tool-tip.

[Thelby]

OH-Oh OK, Now I see what you are saying. Let me try it I will be right back
Tick-Tock_Tick-Tock
OK, I must have done something wrong, because it altered the scale of my population without changing any numbers. My scale says it is still 100, but they are much smaller now.

[Thelby]

OK, Tried it again and yes, it seems to work a bit.
Does any of it depend on where the object creator put the "Hotpoint" in the object???

[Thelby]

And the After, can you see the difference? Notice the dead bush to the right foreground. It is a bit higher now.
Thanks Guys, I Appreciarte it.

[dandelO]

Yes, the hotpoint of the object matters because that's the point TG will instance in the populator. If your object hotpoint is in the centre of the object, instead of at the bottom, change this parent object's 'Y' value so it appears to sit on the terrain correctly, all others should follow suit. (To do this, you'll need to visit the parent object settings and select 'individual object'. If it's left as 'member of a population' you cannot see it(Switch this back when you're done, mind! ). Easier still, load the object on its own, into a scene(at the same scale as here), dicker with the 'Y' height and when you have it looking right, use that 'Y' value in the parent object of the population in the other scene).

Or, get a 3D package to move the hotpoints of your models! Daz studio 2.x is free.

[Thelby]

That's what I thought. I have Lightwave 9.6, DAZStudio 2, Carrara 5,6, and 7 Pro all of which can change the  Hotpoint. I know in Lightwave and Carrara the instance populator has a main object that you can move the Hotpoint around on, in or anywhere you want it. I am not quite sure what you said to do in TG2. I'll have to look at it and see if I can find it. It seems easy enough, I just don't where exactly to look.
Thanks!!!

[dandelO]

In your scene, visit the objects tab, you'll see the pop' and the object it uses to populate, as 2 separate items. Usually, the parent object will come second.
In the 3 x,y,z fields for 'translate'(not rotate) change the 'Y' value to make the main object higher, so the bottom of the bounding box is on the terrain instead of the hotpoint.

[Thelby]

I gotha, that's too easy, LOL 
Thanks So Much!!!