How to make a Real Hud (Like the ATG Javelin)

[Japo32]

Well.. Because I don't want to be lost this post, that maybe could help to someone, I want to rescue it here. So Here it comes:

As you know.. In blender.. if you want to see transparency and see throug it the objects behind, you have to render that faces the last ones. So to do that you create groups. in the example they put into the help in blender.. they say that if you have a cockpit with transparent canopy and transparent hud, to show propertly all... you have to create two groups with the hud and canopy this way:

1. All geometry without group

2. Group A Canopy

3. Group B Hud

So the first you see has to be the last to be drawn and that way you can see everything through the canopy and hud+canopy

So... With my problem to make an real hud.

If I map the faces of the geometry of the hud inside the panel.png in front of it.. would be great.. but when I move side to side.. I would never see how it slip the information "inside" the hud.

the first think I though was to put a transparent plane maped with the pane.png information of the hud behind the geometry of the hud (also transparent but only for viewing through it).

the problem? In the front I would see it smaller (no problem.. the plane behing bigger than the geometry hud plane). Going side to side.. the info slips.. but I would also see that false hud not seeing through the geometry hud.. because it is there. So I had to think of a mask or something. First I though about a dataref that controll something like "hide if this dataref (point of view) is here or there" but could not find any.

So here it comes the exporting groups.

we have:

1. geometry hud. Just for visual, but transparent

2. a box (or plane better) that surrounds the geometry hud (is in the same distance from our eye) but with a hole the same size of the geometry hud (is important because is like the mask we want.

3. the transparent plane with the info of the hud mapped from the panel.png

How we make that box to be a mask. see every geometry but no the 3º option (the transparent plane with info of the hud?) Easy. groups.

If the groups are like this we could see everything.. so is not our purpose:

1. Group C: Geometry hud (transparent)

2. Group B: Box Transparent (mask)

3. Group A: box mapped with info of the hud with the panel.png

but if we turn 2 & 3...

1. Group C: Geometry hud (transparent)

2. Group A: Box Transparent (mask)

3. Group B: box mapped with info of the hud with the panel.png

We could not see the group B because is drawn behind the group A.. but group A HAVE A HOLE IN THE SAME POSITION AND SIZE OF THE GROUPC!!!

here is a drawn of the idea....

[Japo32]

Thinking a little bit more, I though about the internal canopy again.. and a better way to make that mask box:

The arrows are the direction of the normal.

hope it work. the only thing.. is... if works... Will it work also if the cockpit is inside the objects folder and the cockpit.obj is only planes and transparent planes to make clicking?

[Japo32]

Here a video showing how it works (old video.. while building the Javelin)

[Superxpdude]

That's pretty cool.

[Dozer]

This is a very old thread now - but I have to say...

WOW! Very impressed by this; very clever thinking!