debendraroy

Hi all, Got a bunch of questions about Final Gather & Global Illumination in MR. Hoping you'll be kind enough. Thanks for your time. 1. What does the 'incrementally' in 'add fg points' for the fg map creation mean? I thought that it meant that when going from draft preset to low, only the additional points would be calculated, thus saving time. But when I actually tested it, I found no difference in render times. So I'm confused. (I'm only talking about a still, not animation, if it makes any difference). 2. Could someone explain what the bounces in FG are? I've understood the point density, rays per point & interpolation but not sure where the bounces fit in. 3. It is possible to render out a low-res FG map solution & yet use it for the final full res render. But how low-res can it be? Maybe half of the final res? Any other best practices in this regard? 4. With certain scenes viz. Interiors lit by mr sun & sky with sky portals, (in my limited experience) I've found that FG doesn't quite create enough illumination in certain areas. What does one tweak to increase illumination in such problem areas with FG? Maybe increase FG rays per point or interpolation? Or is it a limitation with FG & one would be better served by adding a GI solution or fake lights in the scene? Conversely, how does one decrease illumination from GI. In the same scenes where I felt the FG solution was underwhelming, the GI solution felt a bit overwhelming. Or should I be adjusting the mr Photographic Exposure instead? 5. When using both FG & GI, does the order in which they are cached matter? Is the correct order always GI 1st, FG later? 6. Does increasing FG quality on a per material basis not increase the initial point density? Why does it not reflect in the Max diagnostics? 7. In a youtube tut by I3d, the tutor used 10% of the room diagoanls to arrive at a value for the GI interpolation min & max radius. Is this a good starting formula? 8. In a tutorial by Ramy Hanna, he calculated the GI photon map without all of the lights visible. In the same tut, he then calculated FG without the mr sky portals. Is this the norm or was it something he felt was appropriate for that particular scene? (He did mention that his method isn't entirely physically accurate.) & on a slightly unrelated note, 9. Where do I to plug in the spec map in the Arch & Design material? From reading the Max help files, my understanding is that it is in the Reflection Glossiness & Reflection Color both. Is that correct? Much obliged.

Hi all, I've read a few blog posts about gamma & I believe I have an idea about what it is & its importance. Yet I'm confused about certain things. Let's say I set everything in Max (2012 witth mental ray) to 2.2 (everything ticked & both bitmap input & output set to 2.2). What I want to be able to do is correctly post-process the image in Photoshop. 1. What format should I save the final image in Max if I have to get the most out of post-processing in Photoshop - exr, tif? 16 bit or 32 bit? 2. By setting the bitmap output to 2.2, I'm essentially burning gamma in, right? If I choose not to burn it in, how do I work with it or correct it in Photshop? 3. Is it advisable to burn in gamma correction or not? Or this does not matter so long as the image is correctly de-gammaed or gammaed as the case may be in the post-processing program. 4. Does the mr photographic exposure also affect gamma? How about the image control settings such as highlights/midtones etc? 5. When I bring in jpeg textures with the above settings for the diffuse, can I check 'Use system default gamma' in the import bitmap dialog box? Isn't this essentially the same as 'Use image's own gamma' (in this particular case viz. setting input bitmap parameter to 2.2)? 6. I've read that bump maps from, say xnormal or zbrush, & displacement maps & hdris have a gamma of 1. So here will the override to 1 option need to be checked in the import bitmap dialog? Does the same apply to jpeg bump maps created in Photoshop? Will saving the grayscale bump map in photoshop in any format other than jpeg cause it to have a gamma of 1? Does the same apply to specular & any other grayscale images created in PS? 7. To confuse matters further, I've also read that certain HDRs can have a gamma of 2.2 burnt in. How can one find out what gamma a particular image has? 8. What is the most obvious way in which using an incorrect gamma workflow manifests itself in renders (so that one can correct oneself)? Many thanks for your time & patience.