10-12-2015, 04:03 PM
(10-10-2015, 10:25 PM)tbnkaron Wrote: Does anyone have any idea what is going on page 97? specifically step no. 7? After sketching the line freehand, he says to drop lines to find the curve on the bottom side, whenever I try this I get no where near his line. Please see example below, I have constructed sections following the perspective grid but they do not touch the new line. If you have any idea I would really appreciate the input!
Many thanks!
http://imgur.com/jZMgrDh
Hey I think I know what is the deal. It will be easier to explain in video but not sure how to make that happen.
The best way I can explain it here will be that when it says to project down the line drawn on the surface, you can pick any point in the curve like you have done. But the most advantageous way to do it, is to pick the points that cross at each X section plane. Because you know exactly were the vertical projection meets the ground plane. Watch closely the red projection in the book, you can see that it intersects the X sections.
In your pic the green, magenta and purple planes you drew do not meet the ground plane were you place them. Why? because there is no reference plane, the point is not intersecting any plane previously drawn. At this point the only reference is a point in space (the curve on the surface), which makes it almost impossible to determine the position relative to the rest of the form.
This is why you set the first X sections (planes) at the beginning. Notice how when projecting any new line he always uses the X sections as reference, perfect example is figure 4. in page 96 notice the red verticals.
Hope it helps :")