Population problem (frustrated)

[John]

Hi
I made a mountain scene with a gentle slope. I wanted a forest up to a certain elevation everywhere all the way to the bottom. I found the following info which followed. -
You will be using the Density Shader input of your population. On the Distribution tab of your populator check Use Density Shader then press the "..." button to the right of the node name box. This will pop-up a menu allowing you to either assign an existing shader or create a new one which will function as the Density Shader. Go to Create New Shader -> Colour Shader -> Distribution Shader V4. Click the "..." button again and select Go To "Distribution Shader v4 01". A settings box for the Distribution Shader should come up. Set your altitude (or other) constraints as desired then press the Populate button on your Population and enable Preview Instances to see the changes. Adjust as needed. I checked and filled in the max. elevation. Then I populated.  I used birch trees (.tgo)

In the Preview I saw a smaller white rectangular area which only was populated.
What did I do wrong? What else do I need to do? I did try a number of things for a couple of hours.

[RArcher]

John,

It sounds like you need adjust either the center area of your population, or increase the size of the population bounding box.  These settings can be found in the options for the object.  Center area is the top three boxes labeled Area centre and the size of the population is directly below labled Area length a and Area length b.  Zooming out with the camera and moving into a birds eye view can help sometimes to get your population sizes and distribution correct.

[Mohawk20]

Don't be surprised if the instances are in a nother place than you thought they would come when placing the popualtions bounding box... if you hav a nice heavy displacement, the terrain's altitude could be far above the planet's base altitude, at wich the bounding box is.
The instances will be placed in the terrain above the bounding box.

If you were in side view while placing the bounding box, it might not be under the terrain you thought it would be.

[sonshine777]

What RArcher and Mohawk20 are saying is true. I have added a screen shot to illustrate.

If you are using the default terrain size it will be 10,000 meters by 10,000 meters in size. By default it is placed by the lower left corner which is at 0,0.

If you are using the default population size, it will be only 1,000 meters by 1,000 meters and it is placed by it's center, which is at 0,0.

To get the population to cover the terrain you would need to move the population bounding box to 5000,5000 and increase the size to 10000X10000. You must realise that this will create a lagre number of trees which will add time to your render. Many of those trees will not be seen, but Terragen will still calulate them.

So to echo RArcher, get your camera to a birds eye view and position you population to cover what the camera is going to see when it renders the final scene.

[John]

Hi.
Thanks for all the help from all 3 replies.
I found zooming out with the camera for a bird's eye view did the trick, together with experimenting with the settings as suggested first by RArcher.
Also the attachment and advice sent by sonshine777 was of great help. 

A couple of more questions -
I know each picture is different, but what would a good starting number be for the 3 Center area boxes that are in a row across?
What about Area length a, and b. Also Object space.

One more - Occasionally an Error an Warning thing comes up, I just X it off and everything seems to work. What is that?

Thanks again from a newbie.

[sonshine777]

Do you have a screen shot that you could post of the area or dialog box you are talking about?
There are many places that there are three boxes in a row. I'm assuming that they are refering to x,y,z coordinates, but a screen shot would help in getting the question answered for you.

[Tangled-Universe]

Hi.
Thanks for all the help from all 3 replies.
I found zooming out with the camera for a bird's eye view did the trick, together with experimenting with the settings as suggested first by RArcher.
Also the attachment and advice sent by sonshine777 was of great help. 

A couple of more questions -
I know each picture is different, but what would a good starting number be for the 3 Center area boxes that are in a row across?
What about Area length a, and b. Also Object space.

One more - Occasionally an Error an Warning thing comes up, I just X it off and everything seems to work. What is that?

Thanks again from a newbie.

The starting numbers are totally dependent on the size of your scene and the area which you would like to cover with trees.
Point your mouse in the preview window and you'll find the coordinates of all 3 axes right beneath the preview window.
Move your mousepointer from the start and beginning point of your population and subtract the x-value (or y-value...depends on the rotation) from eachother and that should give a nice start.

You mentioned some errors but I think nobody can say what it is unless you are a bit more specific?
What is the error message?

[John]

Hi sonshine777

I did a screen shot and saved it as a Word Document of the area or dialog box .
It is an attachment. Hope it comes through.
Didn't look like the attachment made it. Not sure how to do that here.
Hope this helps you to help me.
If not I'll try to describe what it looks like:
After I load the Object (tree) this is what I see below:

Distribution  Terrain  Object Scale  Object Rotation  Seed

Area centre         __________      ___________   ___________
Area length a      __________
Area length b      __________
Object spacing    __________

___  Density shader
___  Repopulate every frame            _ Populate
___  Preview Instance

[sonshine777]

John,

Distribution  Terrain  Object Scale  Object Rotation  Seed

Area centre         __5000__      ______0_____   ____5000___  Unless you want your trees to fly only change the left & right. boxes
Area length a      __2000_  Sets the size of the population foot print in one direction.
Area length b      __2000_  Sets the size of the population foot print in the other direction.
Object spacing    ___10__  Determines how far apart the trees are when populated

___  Density shader         When checked will require a shader to tell it how to distribute the trees. Unchecked covers everything.
___  Repopulate every frame   (I don't use this one )        _ Populate      Calculates and places the tree instances.
___  Preview Instance  When checked shows the tree population as bounding boxes.

Hope this helps

[John]

Thanks to sonshine777 for giving me the starting numbers for the 3 Center area boxes that are in a row across, also all the rest.
The explanations for each  will be of help in understanding why.
Zooming out with the camera and moving into a birds eye view can help sometimes
from RArcher is appreciated.
Now for a lot of of experimenting and practice.