June 2014 Video Tutorial - Creating 3D Semi-Transparent Cubes in Xara

[Big Frank]

gary
watched the tutorial and as always a very easy-on-the-brain way to learn new visual concepts & techniques
i highly recommend it and all the others to all artists new and old

but... i noticed a fairly important error, though, whilst watching
perspective - even if you're drawing freehand, it matters
our eyes/brain use the perspective of other objects to judge our own position/distance in the great scheme of things
get perspective wrong and the viewer's eyes/brain calculations subconsciously go "huh?"
at least mine did when you freehand drew the red lines of the rear faces of your cube (ps. backside means but/bootie in uk-english)
when I do a "huh?" i always like confirmation before making a fool of myself (doesn't always work ofc)
i took a screenie of the video and dropped it into xara - the black target is where you placed your rear centre point



i then drew the three vanishing points of the three known faces
which gives me the actual lines of the three hidden faces



and so the white target is the actual position
you can see the perspective is fairly out



which will hinder any further attempt at realism in that drawing

i know how hard perspective is to get right when you do it freehand
but it's a big subject worthy of its own thread
other than that, i liked the effect and also the textures, very handy to have

[theinonen]

I watched the tutorial and actually did my own version as the tutorial can be replicated with Artworks 2 with only minor modifications.

As Artworks 2 has no extrude tool for creating 3D objects in perspective I used an early 3D software instead that can save the scene as a vector image and then imported it into Artworks 2. Quick example below, image on the left shows the cube imported to Artworks 2 and image on the right shows that same cube on the early 3D software. (Yes, I collect old software for no real reason but sometimes they can still have surprising uses.)

[wizard509]

I had noticed that too Frank, but, I thought it was just my error, so didn't pursue it any further.

[Gare]

@ Big Frank—

Yes, I'd agree that perspective is a subject worth of its own tutorial or two.

Moreover, I'm truly happy when someone points out that I'm wrong, because I, too, need to learn (that's one of the perks of being a teacher), and I don't want to propagate mis-information on tg.

I 'eyeballed" the first point as you saw in the video, which the solution, right or wrong (wrong, actually), allowed me to quickly discover all the other points.

So the solution is to bisect all three of the perspective angles to arrive at the centre back point, eh? Good one, and thanks, Frank!

My usual mantra is: if it looks right, then it is right. This begs me to go back someday and see what other miscalculations I've done in my other work!

P.S. Modeling programs just aren't everyone's cup of tea, and I'll try to refrain from bringing a personal hobby into the tutorials in the future. I've been creating models for 23 years (which suggests a lot of free time and patience from a moderately-talented soul), using programs of increasing sophistication, and they're neither free nor inexpensive. Nor easy to learn.

My Best,

Gary

[csehz]

I'll try to refrain from bringing a personal hobby into the tutorials in the future

I have to admit had to enter the 'refrain' word to Google translator, but so please Gare do not hold back these modeling ideas and graphics, they are very good looking ones and also help in thinking out of the box.

Personally Xara will always stay a favourite program for me, but good to know what could be extruded from its line work in other ones. The best would be of course if Xara once also could propose such modeling features. Finally the program has the being 'Swiss knife' approach so why not

[stygg2003]

I totally agree ceshz, gets my vote. I was aware the perspective was slightly out, after all, we've all done plenty of perspective work in the past with Gary and I'm not using this as an excuse for sloppy work on my part but regards the semi-trans. cube, we were not working with perspective, vanishing points, isometric and the rest of it but how to apply shading and transparencies to give a balanced semi-trans. cube which I know how to now. I take on board Big Franks points but in this case I wavered correction for simplicity, the shading and transparencies were the order of the day.

Stygg

[Big Frank]

Moreover, I'm truly happy when someone points out that I'm wrong, because I, too, need to learn

i doubt i was teaching you anything there

[Gare]

@ Big Frank,

Oh, I sucked at geometry, both in high school and college, Frank! And continue to suck. It's a real regret of mine and I excuse it to dyslexia, very real in my life, being left-handed.

If I don't learn from this forum, I'm only cheating myself for putting out and not taking anything in. A sincere thanks for the visual solution to discovering the back point, man! I would have pored through a geometry book for ages were it not for your visual example.

The rest of the tutorial worked, though!

My Best,

Gary

P.S. Once I get some drudge work out of the way this morning, I'll provide everyone with two more transparency-shading challenges, as I'll only have a written tutorial for JHuly this month (and probably post new seamless textures, but no video).

[Gare]

csehz, back in post #27, came up with a marvelous rendition of 9 cubes, stacked horizontally, vertically, and deep.

I thought I'd offer a guide if anyone wants the challenge of recreated the famous puzzle toy in colored glass.



I'm sure this is harder to solve than the puzzle!



My Best,

Gary

[Big Frank]

ok here's my cube
i tried to be clever and do it my better way
then realised i didn't have a my better way
well i did but it was worse
so i did it the gary way
and it works
next time i'll just button it and do it your way