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DickM
03-04-2006, 01:42 PM
Hey everyone
This is my first real GI attempt using EIAS 6.5r2. :argh: I am happy with some of the results and not so much with others. There is obviously a lot for me to learn. I was hoping that this forum would be a good place to learn and hopefully help others who are unfamiliar with EIAS GI understand better as well.

The image: The image is a jungle ruins concept. There is a lot to be done in this image, not just GI tweaks. More texturing and some modeling fixes. The 2 pillars in the middle of the screen for one. There are some faceting problems there. So critique what you will but I'm mostly interested in getting this GI render time down. I have heard EIAS's version of GI is fast. Well, I'd like to see that speed. This image took close to 3 hours to render on a 2.1ghz G5 with 2.5 gig of ram. That's too slow for me :cry:
After I try out any tips I receive, I will post updated renders and render times so that everyone can see what the differences are in speed and image quality.

So, if you have tips and rules of thumb, please share with me and the rest of the EI community.

http://www.morleyarts.com/ruins.html

Thanks

Richard

barnabythebear
03-04-2006, 02:00 PM
Hi Richard,

Thats a really cool image! If you share the project stats and your GI settings i'm sure you'll get some helpfull responses.

ta

nige.

DickM
03-04-2006, 02:08 PM
thanks Nige
Yeah, the image is very big, so you have to expand your window out horizontally. The project info is actually under the image, you have to scroll down to get it. Sorry :banghead: , I should have put this info at the top of the page. I'll do that for future renders.

Thanks again Nige

halfworld
03-04-2006, 02:13 PM
Hey Richard! :thumbsup:

The look is absolutely superb!

About your settings:

Primary rays: 200 looks good enough at the moment.
Secondary rays: Turn these off (0), this type of scene really doesn't need them, dun dun duhhhh, half an hour of your render time (probably more!)... that was easy :)

Sampling level: I'd change this to 8x8, 16x16 is faster but it isn't as sharp. Is your anti-aliasing set to Averaging? The ground especially doesn't look very sharp, that might be the texture though.

Bounces: The general rule here (although break it when ever you like) is 1 bounce for outdoor scenes, 2 for indoor scenes. This, again, will knock another chunk of time off the calculation (possibly another half hour or more).

Everything else looks dandy, so, have a firm handshake from me for a GREAT image so far !!! :beer:
Ian

PS. Are those shadows being created by a gobo or by geometry...?

Giacomo_M
03-04-2006, 02:19 PM
Nice job. The cast shadows of the plants look great.

It's hard to be too sympathetic about the high rendering time--to look at your setup, you've got every render hog in the book (multi-bounce GI, dome lights, hi-poly plants) in there. I'm actually amazed it only took three hours to render. If you want to cut down on the render time, I'd suggest:

A. reducing the bounces to 1, or even 0.
B. Using a lower GI sampling level.
C. Not using the illuminator dome.
D. Rendering the plants on a separate pass and doing the cast shadows with a gobo.

GM

yhloon
03-04-2006, 02:33 PM
Hi Richard,

Finally you found your way here...:)
you have missing for quite some time, must be very busy.

ok! back to the topic... that is very nice image you have done, vert impresive,

my GI setting

1. always set the secondary ray to 0, you can add another light set the GI mode to secondary, for the same (?) result with faster render time... especially with transparent object.

2. bounce light to 1, ant number above 1 won't help a lot, but cause render artifacts.

3. I see you use the old Illumiantor doom together with GI, try avoid that, i think it will solw the rendering because it need to calculate 17 times in your sample... since you use GI sky light, maybe you can increase the density a bit

4. try to avoid very small polygons sitting together in your model (see tumbnail), I think the only solution for this is faster machine and more RAM hehe:twisted:

I'm still usung a very old machine, this tips help me quite alot...I learn from the expert, I think there might something else I have not discovered... any one?:)

regards,
Loon

DickM
03-04-2006, 02:36 PM
Thanks Ian
Great tips! First, it should be noted. I jumped into the deep end after just glancing over the documentation. In the past EI's docs haven't been the best so that's why I just dove in. I plead ignorance on the secondary rays :eek:
The ground texture is actually hi res so your settings change may make a big difference, I'll check. Plus I beleive the displacement was too much and made it look bubbly. I have fixed that, looks much sharper now > see link. I am using adaptive antialiasing, that always looks sharper. I will also lower the bounce number. I will post a new render soon. Oh, and the shadows are mostly low res geometry. I do have one shadow casting tree that's off screen. I have never been able to find a good leaves image to use for a shadow map. Any suggestions?

Again, thanks Ian for the great tips. :thumbsup:

http://www.morleyarts.com/ruins-ground.html

yhloon
03-04-2006, 02:37 PM
opps my reply are a bit too late...

one more thing, if you are using RT shadow transmission to the leaves, try use the tradissional transmission...


regards,
Loon

DickM
03-04-2006, 02:43 PM
Hey GM
Thanks for your input. Yeah, I knew I was doing stuff wrong, hence my involvement here :applause:
I will be reducing bounces and cutting off secondary rays. I will try eliminating the light dome, but the image was a little too dark for my taste with out it. I like the "hot day" look. I will not be doing any post work on this image though. This image WIP is to see what EIAS is capable of in a one time render deal. If it was part of a paying job and there might be fixes coming from a client, yes your right on the money. I would be doing this image in several passes.

Thanks again Giacomo

DickM
03-04-2006, 02:52 PM
Loooooooon
How you doing? Yes, been quite busy as of late. Got some character work I'll be showing here soon. I need some feedback on that as well. It's been so long since I did a real render in EIAS, so I figured I'd do this project to refresh my skills. My character stuff has been more cartoony rendering styles.

Thanks for the tips. Indeed, I have been very nooby about the EIAS GI. :D

I didn't realize the issue with small tightly packed polys. Luckly, most of this image is using relatively low res props, except for the bushes.

And yes, I'm using raytraced shadows. I tried using buffer shadows but got spoiled with the look of raytraced shadows in this image. I think that answers your question.

Glad to be here Loon! :thumbsup:

halfworld
03-04-2006, 03:03 PM
Ahhhh, fabtastic.

That ground looks absolutely exceptional, one wonders how you came up with that great texture (not only one, but me too). If I'm to be hyper critical, I'd say turn the bump down slightly, it's messing a little with the ultra dark shadows.

I'm sure you know this, but with your anti-aliasing try setting both boxes to 255 (on averaging mode). That makes camera automatically 'mackie line' the render, which makes it even sharper still.

Stick with the illuminator man! Ignore loon ;) hehehehehe, I have found it useful to combine GI and Illi domes in certain scenarios, and in this scene I would use one (or a light rig).

If you start to lose colour depth in the image then you have probably set your sky light too high (but 0.55 is great).

I think you have had trouble finding good tree gobos because there are none ! Total Textures have a couple of acceptable shadow maps but nothing beats the real thing...

I'd like to know your Sun shadow settings (light size, samples, and distance to reference).
Also, what's your scene scale (one granger unit = a cm etc).

Ace work, I'm jealous :)
Ian

I'm amazed at the pace of this thread! Great stuff, right back to my beer and painting my speakers :D

DickM
03-04-2006, 03:50 PM
Yeah, I love this texture. I bought it from .............. I can't remember. But I got a full cd and all of them are great. I'll try and find out where it's from and post it for you.

I will lower the bump a bit more, I think your right there.

I really like the skylight option. And yes, I really like the GI dome but what I'll do is render one with and one without. I'll see if the render hit is worth it. I'll post both.

Yeah, I prefer geometry gobos personally. Always seem to look better.

I have messed with the alis boxes in the past, but am unaware of what mackie line is? Enlighten me!

Light settings for main "sun" light:
Type: Spot Light
Intensity: 1.455 > This setting is nice and bright and doesn't blow out areas too much.
Size: 2.0
Shadow: Raytraced, soft edge enabled= Light Radius: 1.0, Samples: 12
Optimize Shadow enabled
Light to ref distance: 400

The scale is what ever EI defaults too I guess. Honestly, I never mess with it. Suggestions maybe?

Oh, and the pace may slow down a bit as I have to render :argh:

Thanks man

Reuben5150
03-04-2006, 04:06 PM
So, if you have tips and rules of thumb, please share with me and the rest of the EI community.

http://www.morleyarts.com/ruins.html

Thanks

Richard


Hey great image !

Ok, my suggestions, some already mentioned..

If you are using a soft edge on the RT shadows (which it looks like), i would turn the soft edge sample level down to about 7.

GI, i would really try and do without the illuminator, as you know, 1 sample= 1 light and with all those lights incuded in the GI calculation its gonna be a big render hit.

Use skylight instead, just turn up the intensity to compensate for tuning off the illuminator, could also try a skymap image, tinting the objects with some sky color adds realism.

Place a "regular" light in the position of your virtual sun, also use this light for shadow generation, included in GI with one bounce.

if you want to control RT shadow opacity, simply duplicate the "sun light" and turn off shadow casting for that light, turn intensity right down, like 0.2, now you have a "shadow opacity controller" :)

If i think of any more i'll post back :thumbsup:


Reuben

halfworld
03-04-2006, 04:22 PM
Yo!

Well, while my speakers dry Ill ramble on some more ;)

When you set both boxes in the AA render tab to 255, camera goes in to Averaging mode (camera even says this in it's interface). If I am not mistaken averaging alters the colours of the pixels along object edges, essentially increasing contrast, when you do this in a dark room it is called Mackie lining - something that the 'Un-sharpen mask...' in photoshop tries to emulate. You end up with a sharper image and we use it for still images 75% of the time. If you start to get jaggies (because the image is too sharp) you can either turn sampling up to 2x2 (adding between 10 and 15% to the render time) or turn off averaging by putting a lower number in the top AA box. Hope you haven't fallen asleep yet!

On with the ramble! I work to a scale of 1 scene unit = 1 cm, so 100 scene units = 1m.

On this scale, in EI, I've found the optimum sun distance from a scene is:
On a super bright mid-summer day: 100,000 scene units.
On an dull (or spring/ autumn) day: 32,000 scene units.
At sunrise or sunset: 400 scene units.

If you want to be true to the real world, multiply all those numbers by 100, but sod that, this is CG and EI doesn't do real world falloff calculations.

So, and I'm not necessarily referring to this scene because you have a great look going, if you move your sun (which must be a spotlight) 32,000 scene units from the action, then look through the sun in the world view, then adjust the cone angles of the sun spotlight so it just covers the scene. One last thing to do, divide the sun reference distance (distance from the scene) by 10. That is you light size (3200). Exception: Never go over six thousand in your sun size, the render hit isn't worth it 99% of the time.

Right! So take an object in your scene, those pillars look about 1.75m tall? how many scene units is their Y in the info box... From there you can work out how many scene units there are to a metre et voila, you can get your sun to an optimum position.

Although, like I said, you have a great look, if it isn't broken, don't do what Ian says :)
Ian

Apologies for boring the crap out of you!!!

plsyvjeucxfw
03-04-2006, 05:12 PM
This is a great thread.

The EI Manuals should be written this way. Instead of a check list of every toggle and entry box, they should teach what this stuff is for and how to use it.

Excellent info everybody, and Richard -- great image!

Igors
03-04-2006, 10:08 PM
Well, I'd like to see that speed. This image took close to 3 hours to render on a 2.1ghz G5 with 2.5 gig of ram. That's too slow for me :cry:

Hi, Richard

Yes, 3 hours is too slow. We've read this thread and we are fully agree with all already given recommendations - all of them are absolute rational. Here are a few things we want to add:

1. Use "Show Samples" diagnostics, let GI shows where are problems

2. Start from maximal simple settings:

- GI: 1 bound, Secondary Rays = 0, Sampling 8x8
- single Light with buffer shadow
- no AA

3. Increase AA (step by step) and see results with "Show Samples". Check geometry in areas are filled with red color. Things like leaves, grass, polygons hairs etc. are heavy for GI always and anywhere cause their geometry is "scattered" that makes GI interpolation technique ineffective. Maybe it makes a sense to exclude such groups from GI calculation

4. Replace buffer shadow with soft ray-trace shadow (not a big speed happy itself). We agree with Ian: GI + dome is a possible but imho not a lucky combo. Adding a light with GI Mode = Exclusive (no shadow) often is much better and faster if you need rid of dark areas

That's all :)

yhloon
03-05-2006, 08:10 AM
I didn't realize the issue with small tightly packed polys. Luckly, most of this image is using relatively low res props, except for the bushes.



opps!, I just discover that the slow down on the tiny poly is due to the GI + shadow transmission... If I turn off the Shadow tranmission the render took 10 times faster to finish.

and

I also learn that it is the matter of modeling, I always model the forhead in low poly, and the eyelid and lips in very details (hi poly) once the engage smoothening the forehead in 2 or 3 step sub-divitionn the eyelid and lips will become too tiny, end up the total polygon up to 30k to 100k...

apologise on any wrong info given :pmy bad...

regards,
Loon

yhloon
03-05-2006, 08:20 AM
1. Use "Show Samples" diagnostics, let GI shows where are problems

2. Start from maximal simple settings:

- GI: 1 bound, Secondary Rays = 0, Sampling 8x8
- single Light with buffer shadow
- no AA

3. Increase AA (step by step) and see results with "Show Samples". Check geometry in areas are filled with red color. Things like leaves, grass, polygons hairs etc. are heavy for GI always and anywhere cause their geometry is "scattered" that makes GI interpolation technique ineffective. Maybe it makes a sense to exclude such groups from GI calculation

4. Replace buffer shadow with soft ray-trace shadow (not a big speed happy itself). We agree with Ian: GI + dome is a possible but imho not a lucky combo. Adding a light with GI Mode = Exclusive (no shadow) often is much better and faster if you need rid of dark areas

That's all :)



thanks Igor:), I learn somrthing new...

Regards,
Loon

DickM
03-05-2006, 04:38 PM
Ok, I got the second render finished. This render has no secondary rays and only 1 bounce. The render time was cut from 2 hours and 51 mins to 1 hour and 47 mins. This is a good increase but not sure if it was worth it. This image, while nice, does not have some of the nicer areas that I liked from the original.

Below the second render link, there is a compare image comparing the 2 parts of the image that I liked more in the original. I don't know if this is due to the removal of secondary rays or bringing down the bounce to 1. Something tells me it's the bounce. But, there may be good news in this. This render still has on my Illuminator dome. I think if I remove this now, I will get an even faster render and it may return some of the darker areas back to the image that I liked. I also will be trying the AA tip that Ian suggested in the next render. Again, I shall post my results. Any new critiques?

note: pay no attention to the new rocks at the top of the steps, these are old objects that were turned on by accident and need to be deleted. They added no extra render time, as you can see, they are extremely low poly.

Additionally: The bump and displacement on the ground object has been lowered. It has a far less bubbly look now. If you see the ground object by itself (see earlier post) you'll notice no bubbly look, but once it's rendered with the rest of the scene, the shadows that fall on the ground makes it to start looking slightly bubbly. I may bring down the displacement just that little bit more.

http://www.morleyarts.com/ruins2.html

http://www.morleyarts.com/compareruins01.html

Thanks

DickM
03-05-2006, 04:45 PM
Also, I should have mentioned, look at the compare image again. I like the original dark area under the 2 rocks that are by the bush on the left. Again, it looks like a light has been turned on underneath the rock and is adding unrealistic lighting.

Giacomo_M
03-05-2006, 05:43 PM
I just want to say that the second image, to my eye, looks every bit as good as the first.

I'd venture to suggest (as others have) that you could probably lose the illuminator and compensate for it by adjusting the sun light and GI settings. (It's at least worth doing a lo-res test render for comparison.)

Also, not to seem lordly, but: rendering in passes is just pretty much standard practice nowadays.

DickM
03-05-2006, 07:33 PM
For the most part I agree with you, but there are some places like the ones I pointed out that are just not as good as the original. My next test will be to cut off the illuminator dome and see if I get those areas back.
As far as passes go, I wanted to stay away from passes with this image. With most of my other work, I work in passes and I'm very familiar with it. This image was to test the capability of EIAS's GI in one render, no post work.

Thanks GM

richardjoly
03-06-2006, 01:50 AM
This is a great thread.
The EI Manuals should be written this way. Instead of a check list of every toggle and entry box, they should teach what this stuff is for and how to use it.


Yes Kurt, I agree with you,that would help a lot. Thanks everyone for the great tips.

DickM
03-06-2006, 03:05 PM
Ok, this render has no illuminator dome, and has averaging mode anti aliasing. I figured from all the remarks I got about the sampling of all the lights in the dome that I would get a much faster render. It was faster, but only by 13 minutes. But hey, 13 minutes is 13 minutes, so I won't complain too much.

The anti aliasing I think I like. Things do look sharper. The illuminator dome being turned off does NOT look good. I've lost the warm daylight haze feel. I will try however to up the skylight intensity to compensate for this as suggested. Although, this may add to the underlighting on some of the objects which I do not like. We'll see.
Reuben suggested that I add a skylight image, well actually there has been one since the first render. I should have noted this. I'm using the same image that is in the backgound, that's why the colors seem to match so well.

http://www.morleyarts.com/ruins3.html

DickM
03-06-2006, 07:03 PM
I forgot to mention that I took Reuben's advice and lowered the soft edge on the raytraced shadow down to 7 samples instead of 12. So I'm not sure if this was the bigger time saver or the removal of the illuminator dome?

Any guesses?

Reuben5150
03-06-2006, 10:55 PM
Both i should think,

Raising the skylight intensity should actually counter that "underlighting" effect, remember that the sykylight model adds its own shadowing, its the bounced rays that cause the underlighting.

For the sake of experience you might try rendering this scene with reverse illumination turned off (no bounces), you'll find its a pretty big difference, not to say the results will be better though.

Also be aware the "optimize shadow generation" can produce artifacts and give slightly differently results, i would turn this off, it may add to the render time, but not a great deal.

Reuben

DickM
03-06-2006, 11:00 PM
More great suggestions Reuben. Thanks, I'll try em out. :thumbsup:

Reuben5150
03-06-2006, 11:06 PM
I think now its just a case of balancing the lighting and shadow, its very close, i would turn off AA, RT soft edge and remove some objects so you can get some fast snapshots.

Reuben

yhloon
03-07-2006, 06:54 AM
Hi Richard,

I do agree the first render looks better, about the third render if you prefer the illuminator doom light maybe you can try what Igor has suggested...

Adding a light with GI Mode = Exclusive (no shadow) often is much better and faster if you need rid of dark areas

regards,
Loon

halfworld
04-06-2006, 10:58 AM
So what ever happened to this very promising image eh!

Did you get to spend more polishing time on it?
Ian

DickM
04-06-2006, 12:23 PM
hey Ian
I got slammed with work, which is a good thing. I have messed with it a bit. The problem is, the slower image looks better than the optimized ones. I got stuck deciding on what to do next. I think I will try loons and igors method of adding another GI light set to exclude shadows. See if that helps instead of the illuminator dome.
I hope I can finish this render up soon. I think I maybe seeing some light at the end of the tunnel.

cjberg
04-06-2006, 03:08 PM
Looks Good Richard...

richardjoly
04-06-2006, 07:35 PM
OK. I'm trying to summarize the wealth of info coming from this thread. Thanks Richard, Loon, Yan, Reuben, Giacomo and Igors for your input. If you read this and find out I went wrong somewhere please correct me.
I understand these are not absolute settings but good guidelines to start with.

Setting up a "Sun" light
Type: Spotlight
Intensity: 1.455
Shadow: Raytrace, soft edges (radius 1, samples 7)
Now for distance and size:
Light to reference distance: Assuming 1 scene unit = 1cm
400 scene units - Sunrise and sunset
32 000 scene units - Dull spring and autumn scenes
100 000 scene units - Superbright mid-summer day
Light size: 10% of the distance used (A distance of 32 000 gives a light size of 3200)
Using a size over 6000 isn't worth it.
Always look through the sun light to adjust the angle so it fits the scene.
To control the shadow opacity you can duplicate the sun light, turn off it's shadow casting, turn intensity way down (0.2) and go from there.

Global illumination
Primary rays: 200
Secondary rays: 0 (To get rid of dark areas, add one GI light, GI Mode = Exclusive, no shadow)
Sampling level: 8X8 (Lowering it to 16X16 will be faster but less accurate)
Bounce: 1 (1 for outdoor scenes and 2 for indoor scenes though it's not a rule)
Use skylight (or skymap) set to around 0.55 (Play with this setting to increase or decrease the color depth of the image.

This is about what I learned from this thread and, again, many thanks to all contributors.

halfworld
04-07-2006, 08:51 AM
Oi Richard! You trying to put the EI training company out of business before we've even started? hehehehe :)

That is an excellent summery, I have, however, never set my Sun intensity quite that high, you might start to see blow out, but that of course might be what you're after.

I think the only thing you missed is:

If your scene contains reflections/ transparency you may want to fake secondary rays without the render hit:
Duplicate sun, set GI mode to secondary. This brightens the reflections of objects but not the objects themselves.

This renders OpenGLs lighting preview useless though because of all the extra light this pumps into the view. I usually switch to 'Camera light only' when I use this trick, either that or I only turn the secondary sun on for renders.

And of course, these settings are all for stills only. Animation is hugely different (and therein lies the training video ;)

!!
Ian

PS. Nice to see you found us CJ :)

richardjoly
04-07-2006, 03:23 PM
...If your scene contains reflections/ transparency you may want to fake secondary rays without the render hit:
Duplicate sun, set GI mode to secondary. This brightens the reflections of objects but not the objects themselves...

Thanks for the correction Yan. This is exactly the kind of info I want to see in a training video. Putting EI Training company out of business!? Au contraire, I'll buy everything!

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