Bump channel heigth? - Polyloop

medeamajic · 10th December 2006, 14:33

How can I set the bump channel heigth for my black and white image? The manual says there should be a slider value for the heigth below the glow channel. I do not see it. I am using a rectangular layer with a black and white image/image map in the bump channel.

benmartin4 · 10th December 2006, 19:54

The manual is missleading. Here is how you do it...
1) Add the image to the Bump channel.
2) Click on top level shader.
3) This will give you a list of all the channels with a few extra options underneath. You should see a slider called "Bump Amplitude" under Bump.

I believe this is what you need.

medeamajic · 10th December 2006, 23:20

With your help I was able to find the bump amplitude slider in the multi chanel panel but it does not change the heigth much. I am not sure why. I posted some screen shots. Maybe I did something wrong. I have a black and white image in the bump channel and it does indent into the object slightly. How can I get it to go deeper? I used a bitmap image.

bwtr · 11th December 2006, 00:01

You have Carrara5 it seems. Why are you not using the displacement Tab?

medeamajic · 11th December 2006, 00:45

I see the screen shot. Could you post a few more screen shots and a little more info. I like the way your image looks with different colors on the riased area.

I want to learn how to do more complex textures. As of now I can set up shader domains and switch them to chrome or glass but the UV mapping and dissplacment is what I need to learn.

bwtr · 11th December 2006, 03:15

In the above "Earth" I just used the exact same texture image as applied to the sphere, but reducing the amplitude down from the default 1.0. It really is that simple. Page 607> of Help.

bwtr · 11th December 2006, 03:48

Checkers and Scan Lines(vert) from the Wizard and a wierd b&w Fractal image I had on file.

ps The Earth maps--of all the planets--in various qualities-- are in the extras stuff disk which comes with Carrara

medeamajic · 11th December 2006, 06:14

Interesting

medeamajic · 11th December 2006, 11:44

I forgot to ask. Can you get deep indents when using the bump channel with grey scale images? I would like to think it should work better. I thought maybe I need to save it in grey scale mod instead of 24 bit color. I will try a few different options later today.

dbigers · 12th December 2006, 02:02

Typically a grey scale map is better. The reason being that Carrara ignores color information in the bump channel. (most apps do). As for deeper bumps. Bump mapping works great for some things. But the appearance of bumps is just that--an appearance. The renderer recalculates the light light leaving a bumpy surface such that the object "appears" to have physical bumps. Regardless of how deep they look, from the side the surface will still be smooth.

Depending on how close you plan to get to an object and some other things which are often scene specific, bump mapping is an excellent choice. It is much easier to render as well, since you are not actually generating geometry, just changing the way the light "appears" to have left the surface.

medeamajic · 12th December 2006, 10:36

Interesting info.

fuzzyeuclid · 12th January 2007, 05:16

Quote:

Originally Posted by medeamajic

With your help I was able to find the bump amplitude slider in the multi chanel panel but it does not change the heigth much.

I had a similar problem. The slider will only increase the value to a slightly higher number, which doesn't make a great deal of difference. However, did you try manually inputing a value? I entered a value of 500 - this produced a much "deeper" bump and with a sigh of relief I achieved the effect I had been looking for.

medeamajic · 12th January 2007, 11:23

Thanks for the info. I will try this soon. I thought my bumps were shallow.

Patrick210 · 12th January 2007, 16:44

You should also understand that "bump" is a render time trick and doesn't produce actual geometry, so you won't see any noticable depth as your facet faces further away from the camera. Displacement creates real geometry.

medeamajic · 12th January 2007, 22:36

Could you show a few screen shots of how this is done? It sounds better than using the bump channel. I am not sure what channel a displacement map would go in. I take it they should be black and white images.

bwtr · 13th January 2007, 01:27

See link seven above.

medeamajic · 13th January 2007, 02:40

I want a few screen shot to show how it is done. I am not asking for screen shots showing what you can do.

What channel is the displament map placed in? That info would help a little along with knowing what parameters to tweak might get me on track.

Patrick210 · 13th January 2007, 03:12

At the top of the shader tree there is a whole tab for displacement. Here's a link for a tutorial Thomas did for displacement:

http://forums.polyloop.net/carrara-t...nt-shader.html

bwtr · 13th January 2007, 03:12

Well you could have looked at link 4!!!!!

And the Help is "interesting" in Carrara.

bwtr · 13th January 2007, 03:33

Carrara Help

10th December 2006, 14:33	#1 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	Bump channel heigth? How can I set the bump channel heigth for my black and white image? The manual says there should be a slider value for the heigth below the glow channel. I do not see it. I am using a rectangular layer with a black and white image/image map in the bump channel. Last edited by medeamajic; 10th December 2006 at 14:48.

10th December 2006, 19:54	#2 (permalink)
benmartin4 Vertex Join Date: Dec 2006 Posts: 3	The manual is missleading. Here is how you do it... 1) Add the image to the Bump channel. 2) Click on top level shader. 3) This will give you a list of all the channels with a few extra options underneath. You should see a slider called "Bump Amplitude" under Bump. I believe this is what you need. __________________ Never been wired or framed!

10th December 2006, 23:20	#3 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	With your help I was able to find the bump amplitude slider in the multi chanel panel but it does not change the heigth much. I am not sure why. I posted some screen shots. Maybe I did something wrong. I have a black and white image in the bump channel and it does indent into the object slightly. How can I get it to go deeper? I used a bitmap image. Attached Thumbnails Last edited by medeamajic; 10th December 2006 at 23:40.

11th December 2006, 00:01	#4 (permalink)
bwtr Brian Join Date: Jul 2005 Location: South Australia Posts: 2,097	You have Carrara5 it seems. Why are you not using the displacement Tab? Attached Thumbnails

11th December 2006, 03:48	#7 (permalink)
bwtr Brian Join Date: Jul 2005 Location: South Australia Posts: 2,097	Checkers and Scan Lines(vert) from the Wizard and a wierd b&w Fractal image I had on file. ps The Earth maps--of all the planets--in various qualities-- are in the extras stuff disk which comes with Carrara Attached Thumbnails

11th December 2006, 00:45	#5 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	I see the screen shot. Could you post a few more screen shots and a little more info. I like the way your image looks with different colors on the riased area. I want to learn how to do more complex textures. As of now I can set up shader domains and switch them to chrome or glass but the UV mapping and dissplacment is what I need to learn.

11th December 2006, 03:15	#6 (permalink)
bwtr Brian Join Date: Jul 2005 Location: South Australia Posts: 2,097	In the above "Earth" I just used the exact same texture image as applied to the sphere, but reducing the amplitude down from the default 1.0. It really is that simple. Page 607> of Help.

11th December 2006, 06:14	#8 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	Interesting

11th December 2006, 11:44	#9 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	I forgot to ask. Can you get deep indents when using the bump channel with grey scale images? I would like to think it should work better. I thought maybe I need to save it in grey scale mod instead of 24 bit color. I will try a few different options later today.

12th December 2006, 02:02	#10 (permalink)
dbigers Spline Join Date: Nov 2005 Posts: 31	Typically a grey scale map is better. The reason being that Carrara ignores color information in the bump channel. (most apps do). As for deeper bumps. Bump mapping works great for some things. But the appearance of bumps is just that--an appearance. The renderer recalculates the light light leaving a bumpy surface such that the object "appears" to have physical bumps. Regardless of how deep they look, from the side the surface will still be smooth. Depending on how close you plan to get to an object and some other things which are often scene specific, bump mapping is an excellent choice. It is much easier to render as well, since you are not actually generating geometry, just changing the way the light "appears" to have left the surface. __________________ Donnie

12th December 2006, 10:36	#11 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	Interesting info.

12th January 2007, 11:23	#13 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	Thanks for the info. I will try this soon. I thought my bumps were shallow.

12th January 2007, 16:44	#14 (permalink)
Patrick210 Pixar want to hire me! Join Date: Apr 2004 Location: Florida, USA Posts: 549	You should also understand that "bump" is a render time trick and doesn't produce actual geometry, so you won't see any noticable depth as your facet faces further away from the camera. Displacement creates real geometry.

12th January 2007, 22:36	#15 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	Could you show a few screen shots of how this is done? It sounds better than using the bump channel. I am not sure what channel a displacement map would go in. I take it they should be black and white images.

13th January 2007, 01:27	#16 (permalink)
bwtr Brian Join Date: Jul 2005 Location: South Australia Posts: 2,097	See link seven above.

13th January 2007, 02:40	#17 (permalink)
medeamajic Now, I learn animation Join Date: Sep 2005 Posts: 1,028	I want a few screen shot to show how it is done. I am not asking for screen shots showing what you can do. What channel is the displament map placed in? That info would help a little along with knowing what parameters to tweak might get me on track.

13th January 2007, 03:12	#18 (permalink)
Patrick210 Pixar want to hire me! Join Date: Apr 2004 Location: Florida, USA Posts: 549	At the top of the shader tree there is a whole tab for displacement. Here's a link for a tutorial Thomas did for displacement: http://forums.polyloop.net/carrara-t...nt-shader.html

13th January 2007, 03:12	#19 (permalink)
bwtr Brian Join Date: Jul 2005 Location: South Australia Posts: 2,097	Well you could have looked at link 4!!!!! And the Help is "interesting" in Carrara.

13th January 2007, 03:33	#20 (permalink)
bwtr Brian Join Date: Jul 2005 Location: South Australia Posts: 2,097	Carrara Help Attached Thumbnails

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