[SOLVED] Billboard tree height issue

[ted.mcclung]

When using grass based impostors, there's a problem with the height of the billboards. When changing the size, the billboards scale from the center, not the bottom.

Here's an example. This is tree billboard that has been added to the world as part of a grass object. It's height is set to 30 meters. Notice the red lines marking the top and bottom.

 

This is a shot of the same tree with it's height set to 10 meters. The bottom of the billboard shifts upward dramatically. 

 

The problem here is that the billboards are meant to seamlessly replace WorldClutter objects (like trees) at a distance, but the scaling behavior of the impostors is different than the scaling behavior of WorldClutter objects. This also renders the min/max height function unusable, because if the trees have any height variation, most of the billboards will be floating above the ground. 

[sebastianbah]

Hi,

 

If I understand you correctly, please, try to check forest sample in Samples demo (samples_2/natures/forest).

Try to Disable fir_meshes MeshClutter, increase near visibility distance of fir_billboards object and set min/max height.

 

So, you can check, that small trees do not hanging and big trees stands on the terrain, not under it.

Then reparent grass from terrain and set it on the plain, position of the impostors will be the same: small trees on the ground, not hanging.

 

If it do not solve your problem, I'm afraid we need a simple test scene or step by step instructions.

[ted.mcclung]

You're right, I discovered that this was happening because the grass object's transform was scaled. I recreated the grass object with a scale of 1 and this feature worked as expected. 

 

Thank you!