Nice mechs, for your first try. I sometimes want to, but then get away from it, but that's because if I do something, I have to do it perfectly and that takes a lot of time.
As for constructive criticism:
Lights. You are making renders and the very first thing you need are lights. The first one is not goos for making nice pictures.
Here is a nice video to help you with this:
http://cgcookie.com/...hting-exercise/
Surface: You should also add some surface to it, so it "stands" on them + the walls. Renders won't look so artificial then. Just make three planes, scale them and put one in each direction to make half of the cube. No need to do this, though.
Gun barrels. Make holes in those guns, so it looks more like a gun and less like a scaled object. There are two ways to do this:
1st: Delete the frontal face, extrude the outer ring of edges that was left behind, scale it down to add thickness to the barrel, but only a bit, then extrude again and hit G, then the dimension which the barrel is on (x, y, or z) and move it to the end of it.
2nd: This way is through modifiers and cutting, it is more precise, but harder to do and it makes a lot of faces, so your rendering time will increase rapidly. The basic principle behind it is to make a smaller cylinder, put it into the original one, make it a separate object (just select it and press P - separate by selection) and then use the "bolean" modifier. You simply set it on difference and select the cylinder object in the lower menu while having selected the rest of the mech. I hope that if you try, you'll get the wanted result, because I had some problems with telling instructions.
Details, details,... You should add some "life" to your pictures/models, because when you look at them you say: "Hey, a bunch of boxes and cylinders glued together,...". Use pictures of mechs as an inspiration and add some nice details to personalize your mechs a bit more.Try to toy a little with the setting, modifiers, or just add a bunch of "thingies" like spikes, gears, etc. (just an example, I don't think they would look nice on both of your mechs).
More advanced shapes. Also, if you have something like shoulders, make it more realistic and more interesting than a simple box scaled and put into some position.
But it is a very good work for your first try.
Edited by Adridos, 19 February 2012 - 08:55 AM.