08-03-2024, 09:17 AM
I also want to comment on the reflection exercise, because I like reflections.
I think you basically get the idea. I did look through the book a little bit to understand the context, and I think what Norling said about the reflection basically being the same as if the mirror were a window with a double of the object on the other side (like the hand with a pane of glass), was a really good tip. What that means, though, is that just flipping the object won't work, you need to use the tricks you've learned to construct in perspective another of the same object, upside down below the 'real' object.
copy and pasting a flipped version of the original works as a trick when you have like a scene of a lake and you flip the far shore. Because it's so far away, and the water will blur the reflection, there's no way anyone would notice any discrepancies in the perspective. But for something like the glass you drew, it's obvious that it's the exact same shape but upside down, so it looks a little flat because the lowest ellipse should have more depth than the top one. I do see you observe this in some drawings, like the pier with the fisherman is drawn reflected (idk what a spile is either), so I think you get that. But I don't see any construction lines. I think it would be a good idea to do the construction for practice even though the book didn't specifically show it.
So for example to do the prism, I start by freehand sketching the bounding box to get an idea of how to set up vanishing points. Then draw the bounding box for the shape. You can simply double the vertical height of the box to get the depth of the reflection because vertical distances won't diminish in space. But if it were mirrored horizontally you would have to use the space doubling trick that I think was probably in an earlier chapter. All we need to do is draw triangles in the constructed planes, and connect the lines. An equilateral triangle will look like this in a square: . So that's why I made the point of the triangle a little back from the edge of the plane. Otherwise it would look weird ( not that I found that out from doing it wrong or anything ;/)
so this is what it would look like. It's a bit distorted on the bottom though, but you can see the triangle part is flattened more near the horizon, but it's reflection has a lot more depth. On yours you technically do have the bottom one deeper though, but It doesn't feel exactly right.
For the cylinder with the slice in it, same thing. set up some perspective, and draw a bounding box that the cylinder would fit in. You can construct circles inside square planes, so we will draw it with planes first. So the dotted lines represent the invisible top of the box if it hadn't been sliced off. I just mark where the slanted plane would go, and take those vertical lengths, and flip them upside down for the reflection. Then you just need to draw ellipses inside each square plane, and connect the lines. And there you have the shape with a constructed reflection. I did all of that just to figure out the top curve of it would be a bit flatter when reflected. So uh... yeah.
Sorry to blow up your post. I'm hoping this is helpful and not just telling you what you know already.
I think you basically get the idea. I did look through the book a little bit to understand the context, and I think what Norling said about the reflection basically being the same as if the mirror were a window with a double of the object on the other side (like the hand with a pane of glass), was a really good tip. What that means, though, is that just flipping the object won't work, you need to use the tricks you've learned to construct in perspective another of the same object, upside down below the 'real' object.
copy and pasting a flipped version of the original works as a trick when you have like a scene of a lake and you flip the far shore. Because it's so far away, and the water will blur the reflection, there's no way anyone would notice any discrepancies in the perspective. But for something like the glass you drew, it's obvious that it's the exact same shape but upside down, so it looks a little flat because the lowest ellipse should have more depth than the top one. I do see you observe this in some drawings, like the pier with the fisherman is drawn reflected (idk what a spile is either), so I think you get that. But I don't see any construction lines. I think it would be a good idea to do the construction for practice even though the book didn't specifically show it.
So for example to do the prism, I start by freehand sketching the bounding box to get an idea of how to set up vanishing points. Then draw the bounding box for the shape. You can simply double the vertical height of the box to get the depth of the reflection because vertical distances won't diminish in space. But if it were mirrored horizontally you would have to use the space doubling trick that I think was probably in an earlier chapter. All we need to do is draw triangles in the constructed planes, and connect the lines. An equilateral triangle will look like this in a square: . So that's why I made the point of the triangle a little back from the edge of the plane. Otherwise it would look weird ( not that I found that out from doing it wrong or anything ;/)
![[+]](images/collapse_collapsed.png "[+]")
Spoiler
so this is what it would look like. It's a bit distorted on the bottom though, but you can see the triangle part is flattened more near the horizon, but it's reflection has a lot more depth. On yours you technically do have the bottom one deeper though, but It doesn't feel exactly right.
For the cylinder with the slice in it, same thing. set up some perspective, and draw a bounding box that the cylinder would fit in. You can construct circles inside square planes, so we will draw it with planes first. So the dotted lines represent the invisible top of the box if it hadn't been sliced off. I just mark where the slanted plane would go, and take those vertical lengths, and flip them upside down for the reflection. Then you just need to draw ellipses inside each square plane, and connect the lines. And there you have the shape with a constructed reflection. I did all of that just to figure out the top curve of it would be a bit flatter when reflected. So uh... yeah.
Sorry to blow up your post. I'm hoping this is helpful and not just telling you what you know already.