PDA

View Full Version : How to load transparent textures in 3D MAX?


marshall6912
11-10-2003, 02:46 PM
I am creating a low poly game model and certain parts calls for transparency.Do anyone know how to load the texture so that certain parts will be transparent when rendered?I've used Paintshop Pro to create 1 gif and 1 png texture with the color black set as the color to be transparent.But when i render it in 3D MAX,the color black is still present.

EricChadwick
11-10-2003, 03:22 PM
In max, transparency doesn't use a key color. It needs a black and white bitmap in the Opacity channel.

There is a way to use the alpha channel of a color map as the opacity map. If you want I can describe that, but it sounds like you have an incompatible texture.

Stroker
11-10-2003, 03:22 PM
I'm a little confused.

Is your GIF/PNG the texture itself with transparency?
Or is your GIF/PNG a B&W mask?

If it's a mask, just load it into the opacity map slot, but first take out the transparency in the GIF/PNG.

EricChadwick
11-10-2003, 03:55 PM
Sounds to me like the former.

One quickie way to do this without making a separate grayscale alphamap, would be to use the Output curves.

Copy the bitmap from Diffuse Color into the Opacity channel. Then in the Output rollout check the Enable Color Map checkbox. In the Color Map window, add a single linear point to the curve, and move it to xy (0,1). This will make all pixels brighter than 000 into full white.

Works OK if you're in a hurry, but a custom opacity bitmap works better.

marshall6912
11-10-2003, 04:17 PM
Originally posted by Stroker
I'm a little confused.

Is your GIF/PNG the texture itself with transparency?
Or is your GIF/PNG a B&W mask?

If it's a mask, just load it into the opacity map slot, but first take out the transparency in the GIF/PNG.

My GIF/PNG is the former with the texture and the color black selected to be the transparent color.

marshall6912
11-10-2003, 04:19 PM
Originally posted by posm
In max, transparency doesn't use a key color. It needs a black and white bitmap in the Opacity channel.

There is a way to use the alpha channel of a color map as the opacity map. If you want I can describe that, but it sounds like you have an incompatible texture.

Can you describe how to use the alpha channel of a color map as the opacity map??Thanx a lot in advance.

EricChadwick
11-10-2003, 04:25 PM
OK...

When the same bitmap is used in both Diffuse and Opacity channels, then the following method can be used to extract the alpha of the Diffuse bitmap. In the Opacity channel, in the Bitmap Parameters rollout:
Alpha Source = Image Alpha.
Mono Channel Output = Alpha.
RGB Channel Output = Alpha as Gray.

Hope that helps.

PokeChop
11-10-2003, 04:49 PM
Here is how I do it with a 32bit Targa file. To see the transparency of a 32bit TGA file in the viewport and have it render correctly here's what I do:

1. Make a TGA material and assign the TGA to the DIFFUSE slot
2. Double-click and open DIFFUSE slot in material editor
3. Uncheck "tile" in the Coordinates section of the TGA properties of the DIFFUSE Targa material (sometimes needed to view transparency in viewports, sometimes not).
4. Check ALPHA in the Mono Channel Output area
5. Go back to the maps section in the material editor
6. Drag the DIFFUSE slot contents to the OPACITY slot and choose INSTANCE for the copy method
7. Make sure you right-click on the active viewport label and choose TRANSPARENCY - BEST to see your results in the viewport

That should get it. I have no idea why unchecking tile in the coordinates section allows you to sometimes see the transparency in the viewport, but it works for me. Hope this is of some help.

marshall6912
11-10-2003, 05:05 PM
Thanx a lot guys,that worked great :)

CGTalk Moderation
01-16-2006, 04:00 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.