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# 1 27-11-2005 , 03:22 PM
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HDRI and Final Gather

Hello everybody.

I'm learning how to use HDRI images and Final Gather. I have a couple of questions here:

1. Should I kill every light on the scene?
2. How can I avoid the grainy textures? (see picture)
3. How can I improve the shadows? (I'm using here an ambient light with 0 intensity and raytrace shadows on)

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# 2 27-11-2005 , 03:48 PM
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here is a better illuminated picture

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# 3 27-11-2005 , 03:59 PM
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Improve the amount of Final Gather rays, remove the ambient light and instead use a plane with very high incandescence. Thats all I can think of.


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# 4 27-11-2005 , 04:15 PM
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thanks!

So, if I understand, I should not use any lights while rendering with Final Gather, right? what would happen? what if I need a very specific light, like a spot light or a point light?

# 5 27-11-2005 , 04:53 PM
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you can add all the light you want. ex:if you have a hdri of a sky and you see thesun, you might add a spot light to "fake the sun light" cuz if you have a blinn material on your model, you wont see any specular highlight.hdri only make your scene to look a lot more realistic, make a better REFLECTION.but if you dont want to add any light, you can.

# 6 27-11-2005 , 05:16 PM
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MattTheMan: About the 2nd question, I increased the Final Gather rays till 2000, and nothing happened. The problem was the occlusion material I was using on the floor and walls. I increased the Samples and I obtained better results.

mcFleury: Thanks for answering! I'll use a directional light for reflections, let's see what happens.


Here is the last render: notice how the grainy texture is practically gone:

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# 7 27-11-2005 , 05:45 PM
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Ok, well what I was suggesting was you kill the ambient light and use a plane that is slightly bigger then your model with its incandescence to the maximum and then render. Tweaking the plane's size should change the amount of light your scene recieves. Try that and post what happens.


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# 8 27-11-2005 , 07:50 PM
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Ok, MattTheMan. I'm rendering the thing. It's taking hours! I don't know why. Usually I render fast, I have a 3.2 Gb processor.

I'll post it when it's done.

# 9 27-11-2005 , 09:09 PM
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Well, it won't render! :angery: the computer crashes or freezes.

I'm using a HDRI image, Global Illumination, Final Gathering, Smooth surfaces, etc., etc., maybe it's too much for this machine... or for my patience...

# 10 27-11-2005 , 09:39 PM
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Well can you post your entire computer stats cuz I too have a 3.2 gb processor but with 2 gb of dual channel dds ram and a 256 Raedon Xctacy graphics card. All of my HDRI renders, like the screwdrivers one I have posted in the Finished Work section take less then about 30 mins to render. The screwdriver took 3 minutes to render, batch, from the command line. It might help you to render stuff as batch renders, from the command line. Look into it. It will help. user added image
Anyway, post the scene file too, I'll try to see what is taking up all of your RAM so that your comp crashes. Hope this helps ya.
ChEeRs, user added image
,MaTt user added image


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# 11 27-11-2005 , 11:50 PM
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I have a 3.2 gb processor with 1 gb ram and a 256 Nvidia graphics card (5200)

Here is my scene file (remeber I'm using a HDRI image, so you'll have tu update it from your computer)

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File Type: rar bluecubes.rar (246.8 KB, 299 views)
# 12 02-12-2005 , 01:03 PM
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Originally posted by MattTheMan
Well can you post your entire computer stats cuz I too have a 3.2 gb processor but with 2 gb of dual channel dds ram and a 256 Raedon Xctacy graphics card. All of my HDRI renders, like the screwdrivers one I have posted in the Finished Work section take less then about 30 mins to render. The screwdriver took 3 minutes to render, batch, from the command line. It might help you to render stuff as batch renders, from the command line. Look into it. It will help. user added image
Anyway, post the scene file too, I'll try to see what is taking up all of your RAM so that your comp crashes. Hope this helps ya.
ChEeRs, user added image
,MaTt user added image

super pc
I m soryy my pc atı radeon 9200 128mb..p4 1.8 ghz 512 mb ddr ram...how much usd and euro:headbang: :headbang:

# 13 02-12-2005 , 08:51 PM
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Mine is worth around 2400 USD. My dad is a computer engineer, and some of the stuff his business doesnt need anymore he gets. HE DID NOT PAY THE FULL 2400 THAT IT WAS WORTH. Dont confuse me with some super rich snob. I'm not. But he also put it together. I think the only things we did buy were the case and the graphics card, which was around $200 - $250, i dunno, I got it for christmas. Anyway, your scene seems to render fine with me... takes about 40-50 minutes. Dunno what the problem may be. Sorry i cant be of help.


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