Stargate¶

Stargate is a Gottlieb System 3 table known for its authentic darkness and powerful "Catch-All" flippers. The VPW project featured professional-grade asset scanning (20k resolution textures, 3D-scanned toys, metrology-measured ramps), Blender toolkit baking, and careful attention to the unique characteristics of Gottlieb hardware. Development went from version 1.3.1 through RC3 to a v2.0 release.

Build Notes¶

Gottlieb System 3 Flippers¶

Gottlieb System 3 flippers are extremely powerful with steep angles. Trademarked as "Catch-All Flippers" by Gottlieb. Red-sleeved coils at 3.85 ohms / 48 volts are standard. Key differences from Williams/Bally:

No reliable live catch
No tap pass
Post passes are risky
Ball frequently goes airborne when kicked on the fly

Tables like Shaq Attack and Waterworld used even stronger orange-sleeve coils.

PAPA Machine Reference

PAPA tournament machines often have modified flipper angles that differ from factory settings. Do not use PAPA videos as definitive reference for flipper positions -- use them only for rough references, not for how normal machines play.

Collidable Ramp Optimization (Dual-Ramp Technique)¶

Complex ramp meshes should be split into two versions: a high-poly visible mesh and a low-poly invisible collidable mesh. VPX calculates collision math for every face in a collidable primitive.

A 15k-face ramp reduced to 4.5k faces still has too many polygons
Target: ~1600 tris for a ramp that serves both visual and physics roles
Technique: delete all non-visible surfaces, export as "low poly," or use Blender's "limited dissolve"

Metal Ramp Mesh Collision¶

JLou disassembled actual ramps and measured them with metrology tools to create accurate meshes. Original Stargate ramp textures were scanned at 20k resolution. Mesh collision works reliably when polygon count is managed.

Gottlieb System 3 Trough Configuration¶

Stargate has 4 balls: one in drain (sw24), three in trough positions (sw34 on swtrough3). Key learnings:

Do NOT add a 4th trough kicker -- only 3 needed
Switch 24 is the drain/outhole
Switch 34 activates on the 3rd ball in the trough
Trough timer interval of 300ms works well
One-way gate sits at the peak of the trough ramp
Physical trough photos from Pinside were essential for mapping switches correctly

Trough Kicker System¶

VPW standard: simulate ball trough using kickers instead of letting balls physically roll through. Benefits:

VPX physics engine does not constantly solve ball positions in the trough
Eliminates ball collision "chattering" when two balls rest against each other
Balls locked in kickers have near-zero impact on physics performance
ROM controls drain kick-in and plunger-lane kick-out solenoids; gravity is simulated via timed kicker chains

VUK Subway with Bezier Curves¶

Subway-to-VUK transitions use bezier curves to create a pipe path for the ball. The underside of the path can clip through other geometry because the ball itself hides the offending geometry.

VPW Check-In/Check-Out Version Control¶

VPW uses a bot-managed system:

Check out latest version before making changes
Upload modified file to personal cloud storage
Check in with version number, download link, and change comments
Always work from the latest checked-in version

Blender Toolkit Render Time¶

A 4K 100% quality bake took under 5 hours. Separate visual test renders (no inserts or flashers baked) were done first to validate physics before committing to full bakes.

Playfield Dimension Verification¶

Quick validation: check if bumper holes and other circular features are actually circular. If circles appear oval, the image has incorrect aspect ratio. Stargate playfield is 20.25" x 46" at 300 DPI. Cross-reference photos from the machine owner for color accuracy.

3D & Art¶

High-Quality Asset Scanning¶

JLou's professional workflow:

Scan all plastics at very high resolution
3D scan all toys
Disassemble and measure ramps with metrology tools
Original texture scans at 20k resolution
Reference photos under controlled white lighting for color accuracy
Full manual scan (58 pages assembled into single PDF)

Total resource library: 10.67 GB, 716 files across 37 subfolders.

Playfield Scan Color Correction¶

Get photos of real playfield under pure white light as color reference
Mesh scan detail with reference color
Paint with high saturation, then apply desaturation, noise, and slight blur
Add wood grain texture using a Multiply layer at ~50% opacity with motion-blurred noise
Verify scan is not being stretched by VPX

Blender Toolkit -- Apply Transformations¶

When baking lightmaps and objects face wrong directions, the fix is "Apply All Transformations" (Ctrl+A). This resets the axis without changing the visual position/rotation. Common issue with complex objects like guardians and pyramid toys.

Scripting¶

VUK Stuck Ball Retry Timer¶

Pattern for handling stuck balls in ROM-controlled VUKs:

Sub SolCallback(23, Enabled)
    If Enabled Then
        If VUK.BallCntOver = 0 Then Exit Sub
        VUK.Kick 90, 12
        Set VUKBall = VUK.Ball
        VUKCheckTimer.Enabled = True
    End If
End Sub

Sub VUKCheckTimer_Timer()
    If Not VUKBall Is Nothing Then
        If VUKBall.Z < 50 Then
            VUK.Kick 90, 14  ' retry with more force
        Else
            Set VUKBall = Nothing
            VUKCheckTimer.Enabled = False
        End If
    Else
        VUKCheckTimer.Enabled = False
    End If
End Sub

This does not override ROM logic -- it only adds a safety net.

Gottlieb System 3 ROM and NVRAM¶

Stargate requires specific ROM files from the "new fixed ROMs" package for VPinMAME v3.6.0-963 beta or higher. The correct NVRAM file must be present for the game to start. NVRAM should be included in VPW release packages for Gottlieb tables.

Kicker/Kick-Back Target Boundary Fix¶

Roth kicking targets assume confinement on both sides. If the ball hits the corner, the target primitive can jump to incorrect positions. Fix: add boundary condition checking in animation logic. Adjust kDist parameter for sensitivity tuning rather than modifying the collidable targets.

Troubleshooting¶

Eye of Ra Multiball ROM Bug¶

Eye of Ra mode incorrectly continues with one ball in play. This is a known ROM bug documented in real tournament rulings. Filed as GitHub issue #493 on vpinball/pinmame. Not fixable at table level.

Staged Flipper Sound¶

Upper staged flipper sound was removed because it sounded odd partway through a staged flip. Potential fix: conditionally enable sound only when staged flippers are enabled in settings.

Game Knowledge¶

Table Darkness is Authentic¶

Stargate is authentically one of the darkest pinball machines ever made. Even with bright LEDs installed, the real machine remains notably dark. Colored GI in the pops and under ramps helps areas stand out and serves the "Stargate spirit" since the original lighting is flat.

Resources¶

Hardware¶

Pico 4 vs Quest 2: Pico 4 significantly better for PCVR pinball development. Superior Fresnel lens, IPD up to ~70mm, comfortable mount. 3800x3800 at 90Hz, comparable to 2D 4K quality.