Itoo Software Forum

Forest Pack => Forest Pro (*) => Topic started by: Mike Truly on April 30, 2010, 03:27:43 PM

Title: 3D Trees Near - 2D Trees Far?
Post by: Mike Truly on April 30, 2010, 03:27:43 PM
There is so much I don't know about FP... and so little time to learn!

I am wondering if there is some way to make this possible.

Seems I am constantly trying to make my scenes more realistic but I tend to stick with 2D trees for render speed.  I create a lot of scenes where there are lots of trees heading off to the horizon (for example a view an aircraft flying over mountainous terrain where there are near trees down below and thousands of far trees going off to the horizon on every mountaintop).

The far trees are no problem... 2D trees work well.  But the near and medium trees look fake and they do not pick up the prevailing light/shadow of the sun and look like 2D trees.  I have been contemplating what kind of low poly 3D tree geometry would work best in order to pick up 3D shading for the near/medium trees but still be fast to render.  I know FP can use 3D trees.

And I have been wondering... is there a way to have sort of a 2D/3D tree distance blend?  Where the user sets distance ranges (like a falloff material) so that 3D trees are used near the camera but are blended to 2D trees far away?

For example, the user would set the distance ranges to be Near=5000ft Far=15000ft.  3D trees would be used at 0-5000ft.  5000ft-15000ft would be a blend of 3D and 2D trees (with fewer 3D trees/more 2D trees toward 15000ft) and only 2D trees after 15000ft.

Is it possible to automatically make FP blend 3D/2D trees like this?  Or do I have to specify separate spline areas for 2D and 3D trees?

Thanks for any ideas!
Title: Re: 3D Trees Near - 2D Trees Far?
Post by: iToo on April 30, 2010, 04:53:02 PM

We have done some tests using this technique, but the result is not optimal. Most of times, the point where 2D and 3D objects blend is too noticeable, specially in animations.

You can simulate it using two Forest objects with opposite Camera->Density Falloff curves. The density of 3D objects decrease with the distance, while the 2D density increase. I've attached a sample scene.

Btw, what render engine do you use ?

Title: Re: 3D Trees Near - 2D Trees Far?
Post by: Mike Truly on April 30, 2010, 05:01:14 PM
Thanks Carlos... I'll take a look.  I think the Density Falloff curves might work for this.  I use the scanline renderer.  Raytrace renderers are impossible to use for the large scenes I create because the render times are very long.

Thanks again.