With the image shown above, that's something i trying to archive.
I just modeled a bottle with a vex glass shader.
I need to map some texture with transparency on top of the glass surface.

question one: I have sorted out the surface where i want to map my texture in SOP with a group op and a uvtexture op. Then, i created a vex layered shader in SHOP and loaded a texture map in the base. I also set the texture tints to diffuse. And then i load a second texture map in layer2 as an alpha matte with texture tints set to alpha. And compositing set to over.

but it doesn't work. U guys have any suggestion? That's any other way to do it? Thanks in advance.

You don't need the second texture map, just make sure the one in the base layer map has the alpha channel embedded in it -e RGBA not just RGB, houdini will then automatically use the alpha channel of the image to work out which bits are transparent.

thanks simon. going to try it soon.

Simon
You don't need the second texture map, just make sure the one in the base layer map has the alpha channel embedded in it -e RGBA not just RGB, houdini will then automatically use the alpha channel of the image to work out which bits are transparent.

and yea, should set the texture map's tint to diffuse and alpha?

Hi jeonado,

Yep, you should set the Texture Tints to “Diff + Alpha”.

Cheers!
steven

stevenong
Hi jeonado,

Yep, you should set the Texture Tints to “Diff + Alpha”.

Cheers!
steven

thanks, steven. I set texture tints to “Diffuse” at first, because it is a default setting. Suprisingly, it works as well.

One thing i noticed that the particular faces with texture map + alpha looks funny on the viewport. But it looks fine when i rendered out.
It only shows the texture map on the viewport, and the transparency area gone empty. Is that the openGL problem?

regards,
jordan.

hi, everyone.

That's a few anti-aliasing filter in the t-map like box, point, gaussian, catmull-rom, sinc, bartlett and hanning.

Since it has not been covered in the vex-layered-surface help file, I would like to ask which one produce better a.a.

and yea what's the different between t-map and s-map? i can tell the “T” is stand for texture. what abt the “S” surface?

thanks,
jordan.

Hi Jordan,

jeonado
thanks, steven. I set texture tints to “Diffuse” at first, because it is a default setting. Suprisingly, it works as well.

The difference between “Diffuse” & “Diff + Alpha” is whether should the shader use the Alpha in the texture map to set the Alpha value. Try it on a simple grid & after it renders, look at the alpha of the rendered image.

One thing i noticed that the particular faces with texture map + alpha looks funny on the viewport. But it looks fine when i rendered out.
It only shows the texture map on the viewport, and the transparency area gone empty. Is that the openGL problem?

Are you displaying the UV Texture SOP or the Shader SOP if you have one in your network? Maybe a screen grab will better show what the problem is.

Hope the above helps!

Cheers!
steven

Hi Jordan,

jeonado
That's a few anti-aliasing filter in the t-map like box, point, gaussian, catmull-rom, sinc, bartlett and hanning.

Since it has not been covered in the vex-layered-surface help file, I would like to ask which one produce better a.a.

You will find more information about the filters online as they are general filters used in CG & not specific to Houdini.

To make use of the filter, please make sure to convert your texture map to the RAT format. To do so, read in your file with a File COP, RMB on the File COP, select “Save Image”, set your path & put the file extension as “.rat”. For example: ctexture_dir/my_texture.rat

and yea what's the different between t-map and s-map? i can tell the “T” is stand for texture. what abt the “S” surface?

S and T refers to “Surface texture coordinates”. You can also think of them as U and V. Typically, if you apply texture coordinates to a grid in the XY plane, U (S) is along the X axis while V (T) is along Y.

With regards to your question, the parameters should read S “Map Filter” & T “Map Filter”.

I hope the above helps!

Cheers!
steven

Steven, your information is really helpful. thank you so much.

Learning houdini is a steep learning curve because it's lack of documentation.
Usually I read the help card, but most of the time I solve the problem by asking question in the forum since this forum is so helpful and also try my luck by clicking on each single setting on the parameter pane.


guys, thank you so much.

jordan.

Hi, everyone.

I am able to knockout the alpha channel now.
With the image shown below, u would notice that the transparency area gone empty. can anyone tell me how to solve this problem?

thanks.
jordan.

Hi Jordan,

With regards to the missing area, there is an OpenGL tab in the VEX Layer Surface shader. Go to the tab & uncheck the “Transparent Texture Alpha” toggle.

I don't disagree that the documentation can be improved but most of what you need is there. Have you checked out the tutorial videos? Please go to the Vislab mirror [sidefx.vislab.usyd.edu.au] and check out the tutorials. They are based on 6.0 but the UI is not drastically different.

There are also other training videos links available which are posted in recent threads under the General Discussion. Please check them out too.

Last but not least, you're welcome.

Cheers!
steven

thanks for your patient once again, steven.


regarding to the image above, the texture meant to be a sticker which stick on top of the surface. So the transparent area suspose to fill up with the surface shader. But now it become empty.

Question: I was using group sop to select the particular faces where i want to map the texture and another group sop to select the whole geometry for diffuse color.

Then i loaded a shader sop and assigned the number of surfaces to 2 group.
One for the diffuse shader another one for the texture map.
Since the texture map is embedded with an alpha channel, the transparent area gonna be empty.

How should i fill up the transparent area with the same shader i applied to the whole box?


thanks,
jordan.

dont forget you can bug people over at odforce.net if you feel you are spamming too much on this forum

also the mail archive might help.

mark2
dont forget you can bug people over at odforce.net if you feel you are spamming too much on this forum

also the mail archive might help.

LOL, thanks for your suggestion anyway, mark.


ok, guys. a better description of my problem with an image attached below.
I just want to fill up the alpha transparent aread.


thanks,
jordan.