hi guys, thanks a lot.

This is to avoid any more confusion:

I should like to create the green box (image 1) with a few clicks/little effort/quickly as possible. This should not interfere with the terrain group, as I will probably move some of the buildings at a later point, or create several alternatives in various layers.

From reading this thread, the easiest method (fewest steps) I can find is the following:

A) Press up arrow to make the protractor blue
B) Place the first point (image 2)
C) Place the second point (to determine building rotation and width)
D) Place the third point* (to determine building length) (image 3)
E) Extrude to the same height as the other building (image 4)

This is easily the quickest method I can think of as each data point only demands one click, except one problem with step D (image 3).

• When I click to make the third point it will snap to the terrain, and make the building tilted.
  Instead of clicking for the third point, I can read off the dimensions (image 3, upper left corner) and then type in: 0;24 where it says 2,6 ; 23,83 (which means Angle ; distance)
  If I could snap to the red axis on the protractor in step D, this would probably be the easiest way possible - no need to create horizontal planes, no need to move objects down to the correct height, no need to switch views/perspectives and the whole process would take about 4 seconds - which is important as I do this process a lot.

@box said:

Use the Up arrow to lock the starting point to the blue axis, click and release, move to the angle you want, click and release to set the first edge, move the mouse and watch for the blue inference, click to finish.

This is brilliant, but it only works because the terrain in your animation is so tiny. In the last step, you snap to the red axis on the protractor. If the terrain continued behind, the tool would insist on snapping to the terrain mesh triangles instead (at least if the mesh is high resolution)

How did you make an animated screenshot, btw?

@jean lemire said:

Hi folks.

Click in sequence on the scenes tabs of this SU file for another method.

I can't destroy the terrain as I need to show several alternatives and might have to slightly alter the buildings later. They need to be in independent groups. I could extrude and group the objects then drop the groups down onto the terrain. But this method requires a few more steps than rotated rectangle directly on terrain, including creating/deleting the above plane, and dropping down (which is pretty quick with the Drop Groups plugin).
It also means switching views/perspective a lot, which is what I'm trying to avoid.

@pbacot said:

Just ignoring the easiest way? Place a pre-made component and make unique. Why draw a rectangle? You can even place a cube, rotate, then push-pull or scale to size. Sounds like you are asking your colleagues to watch a tedious method for no purpose.

But the discussion is good to learn drawing and inference methods.

This method does work, but is slightly more steps than the rotated rectangle method should have have, especially when you have a large variation in required shapes (slightly more tedious to place correctly or resize of the box is way too large or way too small)

A) Copy box
B) paste box somewhere nearby
C) Click on a reference point on box, such as lower corner
D) Click on part of terrain where I want my lower corner
E) Rotate, (shift to lock on blue plane) and click on correct corner rotate
F) Click a second time to get rotation right
G) Resize Z axis
H) Resize X axis
I) Resize Y axis

Which is pretty quick, but not as quick as the 5 steps using rotated rectangle (or at least how quick it would be if step D was easier)

This is tricky to explain, but I think you are missing the point.
Drawing aligned to a specific axis works in SketchUp 2015, but not on a specific plane. I want to draw a rotated rectangle (meaning, the red and green axis is ignored, but the blue axis is not) which ends up horizontally flat even though the terrain below isn't flat. If I wanted to just lock to the red and green axis I would use normal rectangle tool.

If I isolate a small part of the terrain by copying and pasting it outside, the section cut works normally. It appears to be related to size of the terrain.

Section lines are highlighted with red to be more visible.
Any idea why some lines, apparently only those created using the sandbox tool, are not given a proper section cut line? The terrain itself is nothing unusual (somewhat huge).

Wow, it actually works! I was very surprised by this as I have tried all combinations of arrows and shift. Locking using the arrow key works in SketchUp 2016, which my company adopted last week, but not in 2015, as I just tested. Another great improvement.

The only tricky bit now is to lock the last axis correctly - so the plane doesn't tilt with the terrain, but instead locks to the red axis which is horizontal. Luckily touching the red axis and locking with shift works (although it is difficult if there is terrain below which gets locked onto instead), arrow keys unfortunately do not work this time, which would be even quicker.

Thanks a lot!!

Hi,
The reason I need this is that I work in city planning in Norwegian towns, often with official technocrats, politicians and other non-architects. We need a way to explore ideas quickly, often while we discuss them, in order to see the effect of height, vistas, shadow etc - something not clear from a 2D sketch.

My other tactic is to turn off perspective, change to top view and draw on a flat semi-transparent plane way above the terrain, then using the "drop groups"-plugin to drop the shapes down to the terrain below.
Even though this is pretty quick, it means I have to keep hiding/unhiding the plat plane above, and the constant changes in perspective makes my coworkers/clients confused. Also, any seconds I can save are valuable as I do this action a lot.

The terrain is not from Google earth, but high resolution sandbox terrain, although the problem would be the same - I need the buildings placed quickly at the correct elevation. The reason these boxes are different size is that they need to look like or adapt to existing buildings, either already built or visible on the aerial photo projected onto the terrain.

This isn't what I'm looking for. Maybe axis isn't the right word, perhaps what I should say is that I would like to lock to a plane.

I basically want my rotated rectangle to be drawn flat even when the surface i'm drawing on isn't flat.

When I start drawing a rotated rectangle, the circular "rotation tool" appears, and shows what plane I'm drawing on - when I'm drawing on a flat plane, it becomes blue. I would like for it to be blue even when the surface below isn't a flat plane.

I like to use rotated rectangle to draw multiple buildings quickly on topographic terrain models.
This allows me to make a house very quickly in the right dimension and rotation.

My problem is two-fold:

• When I draw the second point, rotated rectangle will insist on snapping to the terrain, meaning my rectangle is drawn at an angle. To avoid this, I have to zoom all the way outside the terrain so it no longer snaps, and the rotation tool turns blue indicating I am drawing on a horizontal plane. I wish I could avoid this, especially in large models where I have to zoom a lot

• When my first "rotated rectangle" point lands somewhere along a vertex line/edge (neither surface nor point) then it refuses to lock on to the flat plane, even when the second point is drawn outside of the terrain - it now uses the line as axis..

If there was a way to lock the rotated rectangle to horizontal plane/blue axis without zooming out or retrying when i hit a vertex, my workflow would be a lot faster.

I have tried drawing on a flat semi-transparent plane above then dropping items down to the terrain, but this is even more time-consuming.

Open GL details says:

Quadro K3100/PCIe/SSE2
GL v. 4.5.0 NVIDEA 347.52

Say I have a terrain, and wish to suggest several road alternatives. I could draw my roads quickly in 2D above then drape down, then change material for the draped areas. However, this gets messy quickly and my terrain is increasingly broken.
I could also make a copy of the terrain each time and move it up 0,1 meter, then drape this, which works fine. However this solution is annoying as the terrain is huge and takes a while simply to copy.

Is there any tool/plugin/clever way to drape a line/shape quickly without affecting the terrain that you drape onto, but instead having the new draped terrain appear in a separate group, (which I can then move up 0,1 to avoid material interference)?

When placing a semi-transparent object on top of another semi-transparent object, I get all kind of weird things happening. In particular, some object becomes entirely transparent even when opacity is set to 99% if the object below also is transparent. However, what object this applies to and not seems random and changes when I change the transparency quality. Notice the yellow boxes becoming totally transparent even though opacity is set to 90%.

Hi,
Thanks a lot for advice.
I've been using both tricks so far - the pencil tool with shift to lock on axis, and to make a semi-transparent plane far above. Both work but are considerably less convenient than being able to stay horizontal once I start drawing. The problem with axis locking (with the pen tool) is that it becomes very hard to control the length of the line, you pretty much have to type in the length (and it takes longer to draw). The problem with the transparent plane trick is simply that its much work, even with the plugin that lets me automatically drop objects onto the terrain. This is especially when I collaborate in workshops, and want the clients to follow what I'm trying to do at all times. They get confused by constantly switching between 2D and 3D, and the objects dropping from the sky.

I didn't expect this to be a standard feature, but it was worth a shot, to see if there are any clever workarounds.

Thanks a lot ely862me, the rectangle tool is great. However, I still have the same problem - drawing on an uneven surface results in rectangles that are uneven meaning not horizontal or flat (seen from straight above). The rectangle does not end up flat at all, it tilts the same way as the landscape below.

pilou: No, I explained badly. I don't need to drape the rectangle, I just want to draw it in-place over an uneven surface. So in the example you provided, all I want to do is draw that rectangle where it is shown (or perhaps closer to that curved surface). The first (of two) corner comes up fine, but the second corner of the rectangle inevitably ends up higher or lower than the first corner because it snaps to the surface below.

What I mean to say is, after drawing the first corner I want to keep drawing on a flat plane, which I can only make work on a flat surface.

I often need to draw something flat on an uneven surface, e.g. when I sketch up up houses based on sattelite imagery (to give my model some context). I do this by drawing a rough rectangle, perhaps rotate it then extrude. However this is tricky when the terrain is uneven as SketchUp will try to snap the second rectangle endpoint onto the surface below, which results in a vertical rectangle.

The only ways I have found to achieve this is to draw the shape on a flat surface, and then to move it in place. This makes it harder to get the shape right and slows me down, especially when there is no flat surface nearby (large model).

Is there any to disable all snapping after having drawn the first point, or perhaps to force SketchUp to keep my rectangle on a particular plane/axis?

Better explanation on attached file:

Hello, I am an architect who uses SketchUp, Revit and AutoCAD to create 3D models. I am very frustrated by how difficult it is to inspect these models, and get a feeling of how it will look. Sketchup walthrough is great, but very slow and laggy with big models. The other programs are hopeless, I don't want to export an animation, but simply to walk around the model/landscape like I do in Battlefield, Mount&Blade or any other game.

Why has no 3D modelling program managed to make a walkthrough engine as intuitive, fast and useful as the simplest FPS game? And more importantly, is there any software or game that lets me import my 3D model to walk around in? Maybe some open-source game that allows imported models in CAD or 3D object format? I simply want to look around using WASD control and mouse to look around, I don't care if it means a gun and crosshair must be included.