SIM GEOMETRY measurements · compatibility · cost

Guide 03 / field geometry

ACC FOV calculator: the vertical convention

ACC’s single-display field is treated as vertical FOV. Its triple story changed: a historical stretched-span answer now sits beside a distinct Triple Screen rendering mode.

Assetto Corsa Competizione is a useful lesson in dating evidence. A still-accessible 505 Games support answer describes triple-monitor support as one image stretched across three screens (historical 505 Games answer). Later official v1.8 release notes refer to a distinct “Triple Screen rendering mode” (official ACC v1.8 notes). Both documents can be authentic and still describe different software eras. The published dataset record marks the 505 answer as historical so it does not override the newer rendering path.

The single-display field is vertical

The conventions record maps ACC’s single-screen FOV control to verticalSpan. The vertical naming, the 10–90 degree range, and the View Settings path come from converging specialist material rather than current first-party documentation, so the record is graded medium confidence (dataset-listed ACC FOV convention source). A vertical angle describes the rays from the eye to the top and bottom of the visible image. It is independent of aspect ratio as a setting convention, although the horizontal view produced from it depends on the render aspect.

That distinction explains why an ACC number can look much smaller than the horizontal result from a calculator without being inconsistent. For the prefilled 597.7 × 336.2 mm panel at 600 mm, the physical horizontal span is about 52.9° while the vertical span is about 31.3°. Entering 52.9 into a vertical field would ask for a much wider projection than the measured screen. For a single display, read the tool’s vertical result and preserve the same center distance used to derive it.

The 505 answer is historical evidence, not noise

The 505 support article says ACC’s triple-monitor support creates a single rendering surface spanning all three monitors and advises configuring the total resolution (historical 505 Games support article). Read on its own, that would imply single-span rendering: one wide projection later bent across angled physical panels. Such a projection cannot provide a separate off-axis frustum for each monitor, so perspective at the side panels differs from native multi-projection geometry.

The old page captures a prior product state rather than a current setup path. It predates v1.8, whose official announcement explicitly mentions fixes for bezel lines and DLSS/FSR behavior in “Triple Screen rendering mode” (official ACC v1.8 release notes). Those details only make sense in the context of a named, current triple rendering path. Use the newer official evidence for present-tense guidance and the older page only as product history.

Current triples are physical-geometry inputs

For current ACC triples, the dataset classifies the mode as native multi-projection and maps the calculator output to physical-geometry, not to a single degrees value. The official v1.8 notes establish that the distinct rendering mode exists (official Triple Screen mode evidence); they do not publish a complete field-by-field setup procedure. Do not rely on unverified JSON keys, exact control names, or configuration recipes.

Measure the center distance, visible panel width, bezel per side, and actual side angle, calculate the physical layout, and enter those same physical quantities in ACC’s triple-screen controls where the current interface asks for them. The ACC record leaves the exact active-FOV JSON key null because the available community field names lack direct supporting evidence.

A triple renderer needs more than the single vertical FOV because it must locate three projection planes. The calculator reports the full visible envelope, center-panel span, active image coverage, and seam occlusion. ACC’s mapping remains physical-geometry: use the measured dimensions to configure the native mode rather than translating the entire rig into one vertical or horizontal field.

Where Pannini correction fits

The dataset also records Pannini projection correction for non-triple wide rendering in ACC (dataset-listed ACC projection guidance). Pannini is a projection choice, not a new physical FOV convention. It can redistribute distortion across a wide single render, which is relevant to an ultrawide or to a spanned output that is not using the dedicated triple path. It does not turn one projection into three independently aligned frustums, and it should not be mixed into a claim that the physical monitor angle has changed.

Keep three layers separate: the measured screen geometry, the angular convention used by the game’s FOV field, and any projection correction applied during rendering. A vertical angle can be correct while a wide rectilinear image stretches near its edges. A Pannini-adjusted image can redistribute that appearance while retaining the same physical monitor. Native triples solve a different problem by assigning projections to separately angled panels.

Single-screen procedure

  1. Measure visible image width and height, plus eye-to-visible-center distance in the driving posture.
  2. Open the prefilled state and replace those dimensions. If the display is curved, add its radius and keep width as the visible chord.
  3. Use the vertical physical span as the ACC single-display baseline because the dataset maps ACC single to verticalSpan (vertical-convention source).
  4. Read the ±10 mm sensitivity band. If the game control forces rounding, record both the physical result and the entered value.
  5. Adjust camera position separately from FOV; do not compensate for an incorrect projection angle by moving the virtual eye.

Open the prefilled ACC vertical-FOV example

Triple-screen procedure

Select the current Triple Screen rendering mode documented by the v1.8-era evidence (official current-mode evidence). Enter measured geometry in the current interface, retaining the exact side angle and bezel definition in your rig record. If a guide repeats only the stretched-span answer, check its date: it may be accurately quoting the historical 505 document (historical single-span evidence) while missing the later mode.

This history is worth preserving because it demonstrates how a citation can be genuine but temporally wrong for present-tense advice. The answer is not to erase old evidence or blindly prefer a newer date. It is to identify what each source actually establishes, attach it to a software era, and leave unsupported details null. That is why the ACC record can tell a richer and more honest story than a timeless settings table.

External sources