Why is the reiver mesh not aligning with ther spline and terrain ?

[MoonBeam]

River mesh is forming above the terrain, cant find the options in the river extension to snap it terrain 

 

[Bryan]

Its the start depth that causing it to raise like this. 

 

[Drummy1]

Bryan, what's the fix if the carve has been done and you still have a portion of floating river?  Is there a way to snap to spline?

[Bryan]

You would want to adjust the Start Depth on the River Extension. 
This will lower the river down as you are wanting. 

 

[TJCarlinIII]

I'm having the same issue.  I have deleted the spline several times and recreated it.  I'm getting the same issue with the mesh being much higher in this one section of the terrain.

[Bryan]

So its the start depth what can cause this. 
Normally you would want to use the carve extension to lower the terrain. 
Creating a flat area of the terrain and putting water on that would be difficult as you are experiencing. 
Then raising and lowering the Start depth would help put it into place, until you found that look you are trying to achieve. 
 

[TJCarlinIII]

I'm doing that.  But after I hit carve, the river is still above the tree lines.  It's happening wherever the mountains meet the ground.  I've tried this is several areas and cannot seem to get this are level to the ground. 

[TJCarlinIII]

I also tried changing the layer to Terrain from PW_Large_Object and adding the spline to the same layer.  No luck.  Maybe I'm missing a small step somewhere.

[TJCarlinIII]

I also have points in that area.

 

[Clyde]

I will attach a picture to try to explain how the river creation algorithm looks at terrain.

 

 

The spline is only used as a suggestion other than the X,Z coordinates.  The river will always flow downhill.  When finding a "High Point" the algorithm backfills to keep the water near level (going downhill somewhat always).

When having a problem, check to see if you have higher points farther down the river.

Also, there are parameters that control the flow depth, but that doesn't seem to be your problem.

[Clyde]

Note: You can use the back filling behavior to your advantage to create ponds and lakes.

 

The following image is of a partially created scene with a lake, dam, and later a river flowing from the bottom of the dam.  There are only 2 nodes/points in the spline used for the lake.  One at the far end, and one placed high on the back of the dam.  The damn is slightly slanted so that a node can be placed on its back. The node on the back of the dam is ever so slightly lower than the node at the far end to keep the lake almost level.

This lake was created by this same tool used to create rivers.

 

See this post for more information on using the river tool: (scroll up in the post for more info):

 

 

[neurodr0me]

On 9/17/2022 at 5:02 PM, Clyde said:

I will attach a picture to try to explain how the river creation algorithm looks at terrain.

 

 

The spline is only used as a suggestion other than the X,Z coordinates.  The river will always flow downhill.  When finding a "High Point" the algorithm backfills to keep the water near level (going downhill somewhat always).

When having a problem, check to see if you have higher points farther down the river.

Also, there are parameters that control the flow depth, but that doesn't seem to be your problem.

 

Was just banging my head against the wall with this issue and this cleared it up nicely.

 

Is there a way to do a sort of "absolute carve" rather than a relative carve, so that after carving, the "high point" will be at the same gentle downward slope as the rest of the spline? Relative carve means the high point will always be higher 🤔

[neurodr0me]

I'm guessing double-posting is just the way of the world here, because posts become uneditable within something like 5 minutes, so I cannot add additional info without just making a new comment...

For future searchers: My effective workaround to getting the high point to come down, is that you can manually drag the spline nodes on the Y axis 'downward' deeper into the terrain--this forces a deeper carve at those nodes, which is close enough to what we want and gives the river the downhill slope it craves.

[Bryan]

Thank you for the insight!