If you set up your mental ray settings and then switch to quicksilver. When you go back to mental ray, all of your settings are reset.

There should be an option in the rendering window to turn off Missing UV and bitmaps Nag so a render can continue on regardless. Specially for network rendering. Most of the time if I cannot see them missing during my test renders I do not need them.
For geometry with missing UV's an option to assign a UV box map automatically to missing UV's would be handy.

This makes my blood boil every day.

1) the region is MODAL. So you make your region render, then try to select an object or change something in the modifier but nothing happens. Moment of panic, then you remember the little "X" top right in the region. Gah.
2) Ok, press the totally unuseful "X". The region area stays there - why? got to open the render window and turn render region off in order to have my viewport clean again.

Currently in order to output a Matte pass (or any other render element) in 3ds Max, you are required to render the main image which could take hours, when the matte pass itself is rendered in mere seconds. The current work around is to disable shadows, reflections, refractions, final gather, GI, etc. in order to decrease render time for the main image. However, this is a pain to have to do.

When assigning a map to the environment slot, the default coordinate mapping should be spherical.

’Make Preview’ shows/uses a different set of video codecs than the render dialog. They really should be the same.

When fine tuning the lighting in a scene, frequently the director will ask for tweaks like bringing down the spec hit from a light. Currently you can only turn the spec off from a light, you can't reduce its strength. You can create multiple lights, but that can lead quickly to a lot of extra useless lights. I'd like to see the Specular and Diffuse checkboxes in the lights changed to spinners.

For more info (including pictures), please visit here:
http://www.neilblevins.com/cg_tools/cg_wishlist/3dsmax/wishlist_surface_type_multipliers.htm

the notion of submitting a file to network rendering is an action that you perform. however, the render dialog list it as a check box (an option). as a result, this check box is often overlooked and we are sending the file again to the network by accident. ideally, the render button would be changed into a "render here"/"render on the network" (flyout maybe?) and the check box would be eliminated. that would take the notion of submitting the job as a more conscious action.

'Tokens' for render output and render elements. Path and filename strings to automate multiple output entries. Strings like 'Scene Name', 'Camera', 'Render Element', etc. That way you could just fill in something like: \GenericProjectName\renders\(sceneName)\(camera)\(renderElement).png - Files would automatically be outputted into folders per render element per camera per project, etc.

It would be great to overhaul the bitmap formats so that options available are consistent. E.g. TGAs can be premultiplied or not, but PNGs can't.

I've recently been doing work where assets are taken straight into apps and often their file format support is limited, having more options from Max would be great rather than having to process them each time through a third app.

We need an updated render element path handling in 3dsmax. For example when the render output path change it doesnt update the path locations of render elements. Although it is common sense.

Anyways for now, the small annoying thing that I have to do is changing paths for 30 something render elements. Every time one by one when I change the render output folder. (happens a lot because of revisions)

We need a single mass editing option for render elements paths.

Please, add antialiasing to renderID channel

Being able to rescale an object with hair&fur applied without it ruining the already created hairstyle.

when you render a UV template, it's handy to use the copy button to copy what you rendered and paste in Photoshop, so you don't have to save a separate file. unfortunately it copies the image at whatever size you are zoomed to in the render output window, so if you render a 2048x2048 template, you can't copy it, because it's either shrunk down to 25% (and the lines are mostly gone) or it's off your monitor.

If there is no light present in the scene, 3ds Max will add a default light when rendering. This is unwanted when using image-based lighting, for example. So the user has to add a light, just to turn it off. This causes the viewport to become dark. There is an option to light the viewport with default lights, but I would prefer a render option for not adding any light sources that are not present.

When using iray as the activeshade renderer in a viewport (which is awesome), you frequently have to close the activeshade preview, then re-launch it for iray/max to re-evaluate the scene.

Simple things like moving lights, objects, etc do not need the scene to be re-evaluated. But altering a light's properties or changing a material does need the activeshade window to be closed, then re-opened, which is slow.

Some control (a button?) which forces the scene to be re-evaluated would be great.

Generate directories that don't exist. When you customize the text path for a render element, it will error out on render if the directory doesn't exist. You have to click on the path icon, create folder, name it, set path. This would be helpful particularly if there are render tokens.

Get a WARNING if you are rendering an orthogonal or perspective viewport and a camera exists in the scene

Allow us to set the default path to be used in state sets
like
/renderoutput/{filename}/{statename}/{statename}.png
The filename is critical to prevent states with the same name in different files trashing each other.