Page 1 of 1

Re: What NOT to do in Google Sketchup

Posted: Sat Feb 04, 2012 3:43 pm
by Support
Paper thin walls:
One common mistake we all do in Sketchup is paper thin walls, floors and windows among many others. The trick to a perfect render is to draw something that you can actually build in real life. A window for example, sure, you can draw a rectangle and assign a glass property to its material, but rendering this will look horrible. Now, if you only push/pull that rectangle 1/8" and render it, it will look like real glass. The reason is simple. Glass refract and reflect light, and all of its beauty depend on its thickness.

Face orientation:
Another mistake many of us do is not paying attention to the orientation of the faces we draw. Sketchup allows you to assign materials to the "front" and "back" faces. Looks cool for paper thin walls, but in real life, walls (as anything else) all have thickness to them, 4" or 6" for example. So if you draw a rectangle and push/pull it by some amount, then all the 6 faces should be the "front". The interior faces of the wall should all be the "back" as we never see them. This is especially important when drawing a glass table top for example. If the faces are not oriented properly, the light reflection and refraction will also be incorrect.

Face on face:
Another important thing to take into consideration is a face sharing the same space as another. For example, draw a floor, then a cube. Place the cube on the floor. Now, the bottom face of the cube is in the same plane as the floor. Again, in real life, this doesn't happen. When 2 things are in contact, there is still space between them, even if it's minuscule. The same goes for the cube on the floor. You should move the cube up by 1/64" or something like that. The reason is again simple. If the cube is glass, the light gets into the cube and when it hits the bottom, the render doesn't know if it hits the floor or the glass. But if the cube is above the floor by 1/64" then render knows that the glass was hit, not the floor. Doing this will always produce the correct render.

If you follow the above guidelines, you will always render perfect scenes.

The only time it's ok to use "paper thin" is for trees using images for the leafs, backgrounds, terrain and stuff like that. Not for table tops, glass, chairs and stuff.