Rendering Critique

[alobartn]

Wow, I'm impressed! It looks great. Too bad it has to be 2700 x 1800 for the magazine.

[cgirerd]

That symbol on the right looks good! I tried the image because the original symbol that was in the plan had really skinny handles that just didn't look right.

Christina

[cgirerd]

How fast do you need it? I might have time to re-run it larger - and with a better refer!

Christina

[alobartn]

Probably anytime before the 31st. No guarantee they'll use it, since I've already submitted, but I'd love to try if you have the time. If you do, I'd make the shadows softer, especially on the left wall, and apply a bump map to the floor.

[George Godwin]

Christina, - I say, "Go for the gusto". You know how to do an excellent Chief/PovRay raytrace render to a degree that would rival the best raytracing software available today. If it takes a few more hours, who cares? You will have demonstrated Chief's true capabilities which too few of us have taken the time to master to an acceptable level.

[cgirerd]

I ran it again last night - 3134 x 2034, with softer shadows and added the bump back to the floor. Because I wasn't sure how long the larger size would take, I just did this Low Rad, but still High AA. It took some time less than 7 hours to finish.

I've also attached a detail so you can see Adam's tilework. Oh - and I did stick back in the refer symbol Adam had originally. (Night8917 - you have wonderfully done refer symbols - I might check into yours for my own project someday!)

Christina

[alobartn]

Wow, am I ever impressed. I miss the spot lights under the cabinets, but the amount of time you saved by turning them off is significant. Please put the PSD on my FTP site and I'll submit it! Thank you for your time and effort

[cgirerd]

You're welcome. I had already emailed it to you. Let me know if you get it that way. If not, I'll post on your FTP.

Christina

[cgirerd]

Oh - and BTW, you can add the effect of under cabinet spot lights in photoshop elements.

Christina

[alobartn]

I just realized that upon looking at your rendering. I was on a different computer when I wrote the last bit. I just sent you a long winded email.

[lbuttery]

Here's a tutorial CD that might be of interest.
I don't have it , just stumbled across it surfing the web

Global Illumination lighting techniques:
http://cgarchitect.vismasters.com/ca...x?product=3677

Lew

[alobartn]

It looks interesting. I'm curious as to how much would apply to lighting within Chief.

[George Godwin]

Christina, - That final render is just excellent and as good as it gets, in my opinion. If either you or Adam can give a simple summary on the lighting and raytrace settings, that would be a good lesson for us less experienced Chief raytracers.

If it is not a problem Adam, could you post the final PSD image on your FTP site for download? I would love to see this final render in full size. Thanks to both of you for your fine work and to John for making the stools.

[cgirerd]

A summary of the raytrace & light settings and my process (more or less as I can remember)...

I actually ended up with three lights in this last raytrace. I have light (no shadows) at "normal" (80 I think) height by the camera which is in the door way at the left edge of the picture. I have another light (no shadows) between the sink and the stove at 70" high so that it won't reflect so brightly on the upper cabinets at the back wall. I have a third light in almost that same place, but at 86" high with shadows turned on and shadow softness set to 4. None of the lights are on auto-intensity. I manually set them. The light with the shadows is on very low so I don't get dark, high contrast shadows.

I first tackled this by turning off all of Adam's carefully placed lights and starting with just one light. I turned off almost all interior items so I could just test lighting. (I have layersets set up with varying amounts of layers to allow for quick testing) I ran a quick raytrace (low rad, no AA). Saw I needed more light, which I expected. So I added another light in the opposite corner of the room from where the camera was and moved the first light closer to the camera. Then I raytraced a couple more times (these quick raytraces also smaller (maybe 600x400) take just a minute or two), adjusting the intensity of the lights until the room had good illumination.

Once the main lighting was set, I began adjusting the main material components. I start with the ceiling and the floor. Then I adjusted the ceiling properties - emissiveness, brightness, etc (I only have the emissive slider about 25% on otherwise it turns too gray), doing quick raytraces to test it. Then the floor. Once I got a material that looked about right (I copied the original photo Adam had taken onto my harddisk so I could compare the real thing), then I adjusted the reflectiveness and bump for it. Once I got it how I like it, then I turned off reflectiveness to speed up my test raytraces. I don't turn it on again until near the end of the process. Then I adjusted the trim for the windows and doors.

Then I adjusted the cabinet materials. Because the lighting was making the upper cabinets much brighter and reddish/yellowish than the lower cabinets, I actually put a different material on the upper cabinets and molding that is much lighter than whan Adam has for the island cabinets. It looks really wierd in the render view, but works in the raytrace. I made sure there was no reflectivity for the upper cabinets and also made them "matte" with "medium" brightness. Tip - I adjust the brightness (dark, medium or light) of any material to get a wider range of color options before looking for another material.

Then I turned all the layers back on (by the appropriate layerset) and did some minor adjusting, like metal finish on the exhaust vent, and got another fabric for the seat cushion. Then I looked to see if anything should be added. I decided to add a few more dishes to the shelving. Then I ran a full screensize raytrace with low rad, normal aa. I then made any adjustments such as the metal should be a little more or less reflective, the blue on the lights needed to be adjusted, etc. Then I ran a fullscreen raytrace with Med Rad and High AA overnight.

Then it was time to add shadows. I went back to the "bare" layerset to speed up raytrace time while testing. At first I tried just turning shadows on for the light closer to the cabinets, but the shadows were very strong and it looked pretty bad (trace ran at low rad and no aa - don't need any aa when just testing lighting and shadows). Finally I added a third light just for the shadows, as I mentioned above, with low intensity. Even at low intensity, I suddenly had too much light and the upper cabinets were glowing again, so I had to turn down the light level on the "main" light by the upper cabinets also. After a couple trial raytraces, it looked good, but the shadow edges were too defined. So for the final run of the night, I turned the "soft shadows" setting to 4 on that light. Then I doubled the pixel size to get it large enough for the magazine to use, but just used Low Radiosity and High AA, as I wanted to make sure it finished overnight. I wasn't sure how doubling the size would increase the length of time. But I know that High AA is more important than going from Low to Med Rad. So it finished sometime under 7 hours.

Then I pulled it into PSE4 and adjusted the contrast and shadows very minimally - that was it.

So that's what I did. Hope that is useful for you...

Christina

[George Godwin]

Thank you Christina. This provides a lot of insights into how to set up the lighting, material adjustments, and the use of layersets and quickie renders for tests. I will be studying your description many times going forward.