Did you know that "architectural materials" and "self illuminated" materials are light emitting (for Mental Ray & Vray) ? If you apply them on a box you will get a similar effect as a "photometric area light" or a "Vray light".
Try to use always soft shadows in your renderings if possible. Hard shadows are looking always very fake. In "Mr Omni/Spot" scale the size of the light in the area light parameters (mental ray).
In Mental Ray you have to use the "RAYTRACED shadows" !
In Vray enable in the Omni/Spot the "area shadow" and scale the size of the light. Soft shadows will take more render time !
To have perfect shadows it is necessary to create all objects with real dimensions.
How to decrease render time for test-renderings:
a) The main setting to decrease the render time is the image size. Normally I use 150x112 pixels as size. It is too small to see the object's details but it’s perfect to understand the light conditions.
b) Lower the Shadow quality !
c) Reduce the polygon number of the objects (try to use the optimize modifier if you don't have any mesh smooth modifier on the objects)!
d) Reduce the photon number or/and the "sample" settings in the render engines. Vray/MentalRay/Brazil RS/FinalRender/ etc.
e) Be careful with the amount of lights (too many lights will make the rendering very slow)!
Do not use editable MESH but ALWAYS editable "POLY".
Editable Poly is optimized for advanced modeling , creates less errors than editable mesh and has many more settings than editable mesh.
If you were working on a object with editable mesh , you can without problems convert it into an editable Poly object.
Instead to mesh smooth a box, use from the "extended primitives" a "chamfer box"... the result is the same, but the chamfer box" has less polygons !
Sometimes all your Vertexes disappear during modeling of an object. To fix this bug try this options:
a) Convert your object again to an editable poly.
b) Convert your object to an editable mesh and then to an editable poly.
c) Save the file, Exit from 3Ds max and open again the file.
d) Save the file, Exit from 3Ds max and merge the object in a new file.
The best light to create Highlights is the Omni light (or MR Omni).
Do not use "area shadows" in Mental Ray, they are very slow and not optimized for Mental Ray.
The best/fastest result is visible when you use Raytrace shadows.
If you are working with the "light-tracer" than you can use "area shadows". The result is the same as in MentalRay with Raytrace shadows.
(For beginners) When you are working sometimes you can't anymore move your object.
Probably you have pressed the key X. Press again X to enable the move tool (GIZMO).
Similar problem: You can select only one object, all other objects can't be selected anymore: probably you have pressed SPACE and locked the object. Press again SPACE to unlock it.
When you create a "loft" object it can happen that the end or beginning of the object has an error.
To fix the problem you should choose "CORNER" vertex on the first and last vertex of your spline.
Download ALWAYS the last service-pack for your 3Ds Max version. It will fix important bugs.
There can be only 2 mistakes when your extruded (spline + extrude modifier) object has an error:
a) you have overlapping segments in your spline.
b) the shape is not closed-check where you did not weld the vertexes.
If you use splines to create shapes, try to use a very small number of vertexes.
If you convert the vertexes in smooth/bezier/bezier-corner you can create very organic and round shapes without a too high number of vertexes (same tip for loft in deformations-scale-panel).
If your interface/panel disappeared you have this options to fix the problem:
a.) Maybe You are in the "expert" mode...press CTR+x...
b.) Customize > Customize User Interface > Toolbars Tab > Reset!
c.) "Start" button on windows > Autodesk > 3Ds Max > change graphics mode !
d.) There should be a 3dsmax.ini file in ur max folder...delete it and start 3Ds Max again...
e.) Customize > load custom UI scheme.